The protein of M(r) 21,000 constituting the prosome-like particle of duck erythroblasts is homologous to apoferritin.

In duck erythroblasts, two major populations of untranslated messenger (m) RNP can be separated by sucrose gradient centrifugation in low ionic strength. One of these contains globin mRNA associated to protein factors, among them the prosomes. The other, sedimenting in the 35S zone, contains non-globin mRNA. From this '35S' mRNP, a new RNP particle called the prosome-like particle was isolated and characterized [Akhayat, O., Infante, A. A., Infante, D., Martins de Sa, C., Grossi de Sa, M.-F. & Scherrer, K. (1987) Eur. J. Biochem. 170, 23-33]. The PLP is a multimer of a protein of M(r) 21,000, and contains small RNA species. The particle is tightly associated with repressed mRNA and inhibits in vitro protein synthesis. We show here that the protein of M(r) 21,000, constituting the prosome-like particle, is apoferritin. Different approaches confirm the RNP character of this particle and provide evidence that some of its RNA species are tRNA. The hypothesis is discussed as to whether (apo-)ferritin might serve other functions in addition to iron storage.     

Steroids, intracellular sodium levels, and Na+/K+-ATPase regulation

In outer medullary kidney tubules, both specific mineralocorticoid, and specific glucocorticoid Na+/K+-ATPase activation in vitro were inhibitable by amiloride, an inhibitor of a number of Na+-transporting mechanisms (Bentley, P.J. (1968) J. Physiol. (Lond.) 195, 317-330; Kinsella, J. L., and Aronson, P. S. (1980) Am. J. Physiol. 238, F461-F469). In addition, dexamethasone raised, whereas amiloride reduced, intracellular Na+ levels. These observations are consistent with the possibility that the steroidal responses are mediated by changes in intracellular Na+ ion activity. However, when intracellular Na+ levels were increased by the incubation of tubule segments in medium containing ouabain (10(-4) M), no Na+/K+-ATPase activation was observed, over incubation periods of up to 6 h. As mineralocorticoid and glucocorticoid effects are maximal within 2 h (Rayson, B.M., and Lowther, S.O. (1984) Am. J. Physiol. 246, F656-F662), these results suggest that the Na+ ion per se does not mediate the steroidal effects observed, directly. Incubation of tubule segments in medium containing 10(-4) M ouabain, at 37 degrees C, for longer periods (18 h), however, did indeed increase Na+/K+-ATPase activity, markedly. Thus, a potential homeostatic mechanism was demonstrable, where a chronic increase in intracellular Na+ level, measured after 2-4 h of treatment, resulted in an increase in Na+/K+-ATPase activity, such that the intracellular Na+ level was restored after 18-20 h of incubation to one not significantly different from the control value. This mechanism, however, appears to be clearly distinguishable from that which mediates steroidal Na+/K+-ATPase activation.     

BUCHBESPRECHUNGEN

Book reviewed in this article:
P apageorgiou , N.: Population Energy Relationships of the Agrimi (Capra aegagrus cretica) on Theodorou Island, Greece.
S chwartz , J. H.; R ollins , H. B., (Ed.): Models and methodologies in evolutionary theory. Bull.
G upta , A. P. (Ed.): Arthropod Phylogeny. New York:
M ayr , E.: Evolution und die Vielfalt des Lebens. übers. aus dem Engl, von K. de S ousa F erreira . Berlin, Heidelberg, New York:
T henius , E.: Die Evolution der Saugetiere.
Proceedings in Life Science. Ecological Genetics: The Interface. Ed. by P. F. B russard . Berlin, Heidelberg, New York:
S tarck , D.: Ver gleichende Anatomie der Wir beltiere auf evolutionsbiologischer Grund-lage. Bd. 2: Das Skeletsystem. Allgemeines, Skeletsubstanzen.
N iethammer , J.; K rapp , F. (Hrsg.): Handbuch der Saugetiere Europas. Bd. I: Rodential (Sciuridae, Castoridae, Gliridae, Muridae). Wiesbaden:
S eidel , F. (Hrsg.): MorphogenesederTiere. Liefg.2: G5-I: Cephalopoda, Tintenfische. Von P. FIORINI.
K raus , O. (Ed.): Das evolutive Plateau Säugetier. (Origin and early evolution of mammals). Karlsruhe 25. - 27. Nov. 1977. Mit Beiträgen von D. S tarck , H.-F. M oeller , W. M aier , G. H ahn . Sonderbande des Naturwissenschaftlichen Vereins in Hamburg Nr. 3. Hamburg und Berlin:
U ebele -K allhardt , B. M.: Human Oocytes and Their Chromosomes. An Atlas. Berlin, Heidelberg, New York:     

Glycosylated and unglycosylated recombinant-derived human stem cell factors are dimeric and have extensive regular secondary structure.

We have recently described the identification, isolation, and characterization of a factor, termed stem cell factor (SCF), which acts on primitive hematopoietic progenitors of the marrow. A soluble form of the factor was isolated from the conditioned medium of a rat cell line (Zsebo, K. M., Wypych, J., McNiece, I. K., Lu, H. S., Smith, K. A., Karkare, S. B., Sachdev, R. K., Yuschenkoff, V. N., Birkett, N. C., Williams, L. R., Satyagal, V. N., Tung, W., Bosselman, R. A., Mendiaz, E. A., and Langley, K. E. (1990) Cell 63, 195-201) and rat and human cDNAs have been cloned (Martin, F. H., Suggs, S. V., Langley, K. E., Lu, H. S., Ting, J., Okino, K. H., Morris, C. F., McNiece, I. K., Jacobsen, F. W., Mendiaz, E. A., Birkett, N. C., Smith, K. A., Johnson, M. J., Parker, V. P., Flores, J. C., Patel, A. C., Fisher, E. F., Erjavec, H. O., Herrera, C. J., Wypych, J., Sachdev, R. K., Pope, J. A., Leslie, I., Wen, D., Lin, C.-H., Cupples, R. L., and Zsebo, K. M. (1990) Cell 63, 203-211). The cDNAs encode amino acids C-terminal to those found in the isolated natural form, including a putative transmembrane domain. This paper describes the structural characterization of soluble forms of recombinant human SCF purified from Escherichia coli (unglycosylated) and from Chinese hamster ovary (CHO) cells (glycosylated). Fluorescence emission spectra indicate that the single Trp residue is present in a hydrophobic environment. Circular dichroism and infrared spectroscopy indicate considerable secondary structure, including both alpha-helix and beta-sheet. Molecular weight determinations by sedimentation equilibrium show that the molecules are dimeric (noncovalently associated), and gel filtration analyses are consistent with this conclusion. The CHO cell-derived SCF is about 30% carbohydrate by weight, with both N-linked and O-linked sugar. The presence or absence of the carbohydrate does not influence the results of the various structural analyses.     

Role of the sonchus yellow net virus N protein in formation of nuclear viroplasms

Sonchus yellow net virus is a plant nucleorhabdovirus whose nucleocapsid (N), phosphoprotein (P), and polymerase (L) proteins form large viroplasms in the nuclei of infected plants (C. R. F. Martins, J. A. Johnson, D. M. Lawrence, T. J. Choi, A. Pisi, S. L. Tobin, D. Lapidus, J. D. O. Wagner, S. Ruzin, K. McDonald, and A. O. Jackson, J. Virol. 72:5669-5679, 1998). When expressed alone, the N protein localizes to the nuclei of plant and yeast (Saccharomyces cerevisiae) cells and the P protein is distributed throughout the cells, but coexpression of N and P results in formation of subnuclear viroplasm-like foci (M. M. Goodin, J. Austin, R. Tobias, M. Fujita, C. Morales, and A. O. Jackson, J. Virol. 75:9393-9406, 2001; M. M. Goodin, R. G. Dietzgen, D. Schichnes, S. Ruzin, and A. O. Jackson, Plant J. 31:375-383, 2002). We now show that the N protein and various fluorescent derivatives form similar subnuclear foci in plant cells and that homologous interactions mediated by a helix-loop-helix region near the amino terminus are required for formation of the foci. Mutations within the helix-loop-helix region also interfere with N- and P-protein interactions that are required for N and P colocalization in the subnuclear foci. Affinity purification of N proteins harboring single mutations within the motif revealed that Tyr40 is critical for N-N and N-P interactions. Additional in vitro binding assays also indicated that the N protein binds to yeast and plant importin alpha homologues, whereas mutations in the carboxy-terminal nuclear localization signal abrogate importin alpha binding. The P protein did not bind to the importin alpha homologues, suggesting that the N and P proteins use different pathways for nuclear entry. Our results in toto support a model suggesting that during infection, the N and P proteins enter the nucleus independently, that viroplasm formation requires homologous N-protein interactions, and that P protein targeting to the viroplasm requires N-P protein interactions that occur after N and P protein import into the nucleus.     

Oxidative activation of protein kinase Cgamma through the C1 domain. Effects on gap junctions

The accumulation of reactive oxygen species (ROS, for example H2O2) is linked to several chronic pathologies, including cancer and cardiovascular and neurodegenerative diseases (Gate, L., Paul, J., Ba, G. N., Tew, K. D., and Tapiero, H. (1999) Biomed. Pharmacother. 53, 169-180). Protein kinase C (PKC) gamma is a unique isoform of PKC that is found in neuronal cells and eye tissues. This isoform is activated by ROS such as H2O2. Mutations (H101Y, G118D, S119P, and G128D) in the PKCgamma Cys-rich C1B domain caused a form of dominant non-episodic cerebellar ataxia in humans (Chen, D.-H., Brkanac, Z., Verlinde, C. L. M. J., Tan, X.-J., Bylenok, L., Nochli, D., Matsushita, M., Lipe, H., Wolff, J., Fernandez, M., Cimino, P. J., Bird, T. D., and Raskind, W. H. (2003) Am. J. Hum. Genet. 72, 839-849; van de Warrenburg, B. P. C., Verbeek, D. S., Piersma, S. J., Hennekam, F. A. M., Pearson, P. L., Knoers, N. V. A. M., Kremer, H. P. H., and Sinke, R. J. (2003) Neurology 61, 1760-1765). This could be due to a failure of the mutant PKCgamma proteins to be activated by ROS and to subsequently inhibit gap junctions. The purpose of this study was to demonstrate the cellular mechanism of activation of PKCgamma by H2O2 and the resultant effects on gap junction activity. H2O2 stimulated PKCgamma enzyme activity independently of elevations in cellular diacylglycerol, the natural PKC activator. Okadaic acid, a phosphatase inhibitor, did not affect H2O2-stimulated PKCgamma activity, indicating that dephosphorylation was not involved. The reductant, dithiothreitol, abolished the effects of H2O2, suggesting a direct oxidation of PKCgamma at the Cys-rich C1 domain. H2O2 induced the C1 domain of PKCgamma to translocate to plasma membranes, whereas the C2 domain did not. Direct effects of H2O2 on PKCgamma were demonstrated using two-dimensional SDS-PAGE. Results demonstrated that PKCgamma formed disulfide bonds in response to H2O2. H2O2-activated PKCgamma was targeted into caveolin-1- and connexin 43-containing lipid rafts, and the PKCgamma phosphorylated the connexin 43 gap junction proteins on Ser-368. This resulted in disassembly of connexin 43 gap junction plaques and decreased gap junction activity. Results suggested that H2O2 caused oxidation of the C1 domain, activation of the PKCgamma, and inhibition of gap junctions. This inhibition of gap junctions could provide a protection to cells against oxidative stress.     

Tyrosine and carboxyl protonation changes in the bacteriorhodopsin photocycle. 2. Tyrosines-26 and -64

Low-temperature Fourier transform infrared (FTIR) and UV difference spectroscopies combined with selective tyrosine nitration and tyrosine isotopic labeling have been used to investigate the participation of tyrosines-26 and -64 in the bacteriorhodopsin (bR) photocycle. Nitration of Tyr-26 has no detectable effect on the FTIR or UV difference spectra of the BR570----K630 or BR570----M412 transitions. In contrast, nitration of Tyr-64 causes changes in both the FTIR and UV spectra of these transitions. However, this nitration does not alter tyrosine peaks in the FTIR difference spectra which have previously been associated with the protonation of a tyrosinate by K630 and the deprotonation of a tyrosine by M412 [Roepe, P., Ahl, P. L., Das Gupta, S. K., Herzfeld, J., & Rothschild, K. J. (1987) Biochemistry (preceding paper in this issue)]. Instead, Tyr-64 nitration appears to affect other tyrosine peaks. These results and changes in UV difference spectra upon Tyr-64 nitration are consistent with the deprotonation of Tyr-64 by M412 as concluded previously [Scherrer, P., & Stoeckenius, W. (1985) Biochemistry 24, 7733-7740]. Effects on chromophore vibrations caused by Tyr-64 nitration are unaltered upon reducing the nitrotyrosine to aminotyrosine with sodium dithionite. Finally, nitro-Tyr-64 causes a shift in the frequency of a positive peak at 1739 cm-1 in the BR570----M412 FTIR difference spectrum which reflects the protonation of a carboxyl-containing residue [Engelhard, M., Gerwert, K., Hess, B., Kreutz, W., & Siebert, F. (1985) Biochemistry 24, 400-407; Roepe, P., Ahl, P. L., Das Gupta, S. K., Herzfeld, J., & Rothschild, K. J. (1987) Biochemistry (preceding paper in this issue)]. The shift does not occur for samples containing amino-Tyr-64. These data suggest that Tyr-64 may interact with this carboxyl group.     

Book Reviews

Books reviewed in this article:
BERNARDO, J. M., BERGER, J. O., DAWID, A. P., and SMITH, A. F. M. (editors). Bayesian Statistics 6.
VAN DER VAART, A. W. Asymptotic Statistics.
NOLAN, D. and SPEED, T. StatLabs: Mathematical Statistics Through Applications.
BINNS, M. R., NYROP, J. P., and VAN DER WERF, W. Sampling and Monitoring in Crop Protection: The Theoretical Basis for Developing Practical Decision Guides.
DIECKMANN, U., LAW, R., and METZ, J. A. J. (editors). The Geometry of Ecological Interactions: Simplifying Spatial Complexity.
LAWSON, A., BIGGERI, A., BOHNING, D., LESAFFRE, E., VIEL, 3.-F., and BERTOLLINI, R. Disease Mapping and Risk Assessment for Public Health.
BLAND, M. and PEACOCK, J. Statistical Questions in Evidence Based Medicine. Oxford University Press, Oxford, 2000.
MANLY, B. F. J. Statistics for Environmental Science and Management.
RÍOS INSUA, D. and RUGGERI, F. (editors) Robust Bayesian Analysis.
BARNDORFF-NIELSEN, 0. E., COX, D. R., and KLUP-PELBERG, C. Complex Stochastic Systems.
PETRIE, A. and SABIN, C. Medical Statistics at a Glance.
THERNEAU, T. M. and GRAMBSCH, P. M. Modeling Survival Data: Extending the Cox Model.
TAN, W.-Y. Stochastic Modeling of AIDS Epidemiology and HIV Pathogenesis.
CHATFIELD, C. Time-Series Forecasting.
MATTHEWS, J. N. S. An Introduction to Randomized Controlled Clinical Trials.
CLARK, I. and HARPER, W. V. Practical Geostatistics 2000.
TANIGUCHI, M. and KAKIZAWA, Y. Asymptotic Theory of Statistical Inference for Time Series.
KARIAN, Z. A. and DUDEWICZ, E. J. Fitting Statistical Distributions: The Generalized Lambda Distribution and Generalized Bootstrap Methods.     

X-ray absorption spectroscopic studies of the high-spin iron(II) active site of isopenicillin N synthase: evidence for Fe-S interaction in the enzyme-substrate complex.

Isopenicillin N synthase from Cephalosporium acremonium (IPNS; M(r) 38.4K) is an Fe(2+)-requiring enzyme which catalyzes the oxidative conversion of (L-alpha-amino-delta-adipoyl)-L-cysteinyl-D-valine (ACV) to isopenicillin N, with concomitant reduction of O2 to 2H2O. Chemical and spectroscopic data have suggested that catalysis proceeds via an enzyme complex of ACV bound to the iron through its cysteinyl thiolate [Baldwin, J. E., & Abraham, E. P. (1988) Nat. Prod. Rep. 5, 129-145; Chen, V. J., Orville, A. M., Harpel, M. R., Frolik, C. A., Surerus, K. K., Münck, E., & Lipscomb, J. D. (1989) J. Biol. Chem. 264, 21677-21681; Ming, L.-J., Que, L., Jr., Kriauciunas, A., Frolik, C. A., & Chen, V. J. (1991) Biochemistry 30, 11653-11659]. Here we have employed the technique of Fe K-edge extended X-ray absorption fine structure (EXAFS) to characterize the iron site and to seek direct evidence for or against the formation of an Fe-S interaction upon ACV binding. Our data collected in the absence of substrate and O2 are consistent with the iron center of IPNS being coordinated by only (N,O)-containing ligands in an approximately octahedral arrangement and with an average Fe-(N,O) distance of 2.15 +/- 0.02 A. Upon anaerobic binding of ACV, the iron coordination environment changes considerably, and the associated Fe EXAFS cannot be adequately simulated without incorporating an Fe-S interaction at 2.34 +/- 0.02 A along with four or five Fe-(N,O) interactions at 2.15 +/- 0.02 A.(ABSTRACT TRUNCATED AT 250 WORDS)     

RECENT ORNITHOLOGICAL PUBLICATIONS

Books: Andrews , I.J. 1995. The Birds of the Hashemite Kingdom of Jordan Barrows , E.M. 1995. Animal Behavior Desk Reference Briffett , C. & Supari , Sutari bin Catchpole , C.K. & Slater , P.J.B. 1995. Bird Song: Biological themes and variations Clement , P. 1994. The Chiffchaff Collar , N.J., Crosby , M.I. & Stattersfield , A.J. 1994. Birds to Watch 2: The world list of threatened birds Flade , M. 1994. Die Brutvogelgemeinschaften Mittel- und Nord-deutschlands Gehlbach . F.R. 1994. The Eastern Screech Owl: Life history, ecology and behavior in the suburbs and countryside Gill , F.B. 1995. Ornithology. 2nd edition Holz , R. 1994. Bibliographie ornithologischer Artikel aus Zeit-schriften und Periodika der DDR Hora , J., Kanuch , P. et al. 1992. Important Bird Areas in Europe Czechoslovakia Howell , S.N.G. & Webb , S. 1995. A Guide to the Birds of Mexia and Northern Central America Jackson , C. 1994. Bird Painting: The eighteenth century Krattiger , A.F., Mc Neely , J.A., Lesser , W.H., Miller , K.R., ST. Hill , Y. & Senanayake , R. (eds) Love , J.A. 1994. Penguins Reilly , P. 1994. Penguins of the World Lutwack , L. 1994. Birds in Literature Miller , R.I., ed. 1994, Mapping the Diversity of Nature Nechaev , V.A. 1995. Game- and Protected Birds of Sakhalin and the Kuril Islands (in Russian) Nettleship , D.N., Burger , J. & Gochfeld , M. 1994. Seabirds on Islands: Threats, case studies and action plans Olsen , K.M. & Larsson , H. 1995. Terns of Europe and North America Ridley . M. 1995. Animal Behavior Searcy , W.A. & Yasukawa , K. 1995. Polygyny and Sexual Selection in Red-winged Blackbirds Small , A. 1994. California Birds: Their status and distribution Summers , R.W. & Mc Adam , J.H. 1993. The Upland Goose: A study of the interaction between geese, sheep and man in the Falkland Islands Sutherland , W.J. & Hill , D.A. (eds). 1995. Managing Habitats for Conservation Walters , M. 1994. Birds' Eggs Wheeler , B.K. & Clark , W.S. 1995. A Photographic Guide to North American Raptors Also Received: Cabot , D. 1995. Irish Birds Chandler , D. & Langman , M. 1995. Bird Habitats and Conservation Chebez , J.C. & Bertonatti , C.C. 1994. La Avifauna de la Isla de los Estados, Mas de Aflo Nuevo y Mar circundante Tierra de Fuego, Argentina Dawson , L. & Langman , M. 1995. Bird Behaviour Dekker , R.W.R.J., Mc Gowan , P.J.K. & WPA/Birdlife /Species Survival Commission Megapode Specialist Group Granlund , J., Mc Peck , G.A. & Adams , R.J. 1995. The Birds of Michigan Geligan , J., Smith , M., Rogers , D. & Contreras , A. (eds). 1994 Green , I. & Moorhouse , N. 1995. A Birdwatchers' Guide to Turkey Hayman , P., Arlott , N. & Tarboton , W. 1994. Birds of Southern Africa: The SASOL Plates Collection Hustings , F. & van Dijk , K. 1994. Bird Census in the Kizilirmak Delta, Turkey, in Spring 1992 Inskipp , C. & Inskipp , T. 1994. An Introduction to Birdwatching in Bhutan Jenkins , D. (ed.). 1995. Proceedings of the 6th International Symposium on Grouse, 20–24 September 1993, Udine, Italy Kivit , H., Nijmeijer , H. & Ovaa , A. (eds). 1994. Wader and Waterfowl Migration in the Cukurova Deltas, South Turkey, Spring 1990 Kutac . E.A. & CARAN, C. 1994. Birds and Other Wildlife of South Central Texas: A handbook Monroe , B.L., JR. 1995. The Birds of Kentucky Noble , W.T. de (ed.). 1995. Birds of the Messolonghi Wetlands, Eastern Mediterranean Wader Project, Spring 1990 Olney , P.J.S., Ellis , P. & Fisken , F.A. (eds) Olsen , J. 1994. Some Time with Eagles and Falcons Palmer , M. 1994. A Birdwatching Guide to the Costa Blanca. Revised edition Piper , S.E. 1994. Mathematical Demography of the Cape Vulture Rogers , D.W. 1994. Site Guides: Costa Rica, a guide to the best birding locations. Pp. 90. McMinnville, Oregon: Cinclus Rogers , D.W. 1994. Site Guides: La Ruta Maya, a guide to the best birding locations of the Yucatan, Belize, Guatemala, Honduras and El Salvador Rogers , D.W. 1993. Site Guides: Venezuela, a guide to the best birding locations SKARPHÉØINSSON, K.H., PÉTURSSON. G. & HEMARSSON, J.Ó. 1994. Uatbreisla varpfugla à Suvesturlandi: Könnum 1987–1992 [Atlas of Breeding Birds in Southwestern Iceland: A survey 1987–19921 Speight , G. 1995. Finding Birds in Britain: A site guide Stone , C.J., et al. 1995. An Atlas of Seabird Distribution in Northwest European Waters Sueur , F. & Commecy , X. 1990. Guide des Oiseaux de la Baie de Somme Thomson , T. 1994. Birding in Ohio. 2nd edition Walters , M. 1995. The Pocket Guide to Birds of Britain and Europe Zink , G. & Bairletn , F. 1995. Der Zug europäischer Singvögel: Ein Atlas der Wiedefunde beringter Vögel     

Books

Books reviewed in this article: Adar , M. (ed.). 1993. Bird Sounds (in Hebrew) Baumel , J.J., King , AS., Breazile , J.E., Evans , H.E. & Van den Berge Bergman , H.-H. 1993. Der Buchfink. Born , E.G. & Flores , D. 1993. The Mississippi Kite. Bhushan , B., Fry , G., Hibi , A., Mundkur , T., Prawiradilaga , D.M., Sonobe , K. & Usui , S. 1993. Clement , P., Harris , A. & Davis , J. 1993. Finches & Sparrows. An identification guide. Crawley , M.J. 1993. GLIM for Ecologists. Methods in ecology series. Dowsett , R.J. & Forbes -Watson , A. 1993. Checklist of Birds of the Afrotropical and Malagasy Regions. Dowsett , R.J. & Dowsett -Lemaire , F. 1993. A Contribution to the Distribution and Taxonomy of Afrotropical and Malagasy Birds. Dvorak , M., Ranner . A. & Berg . H.-M. 1993. Atlas der Brutvögel Österreichs Glutz von Blotzheim , U.N. & Bauer , K.M. 1991. Handbuch der Vogel Mitteleuropas. Band 12/I and II: Passeriformes (3. Teil). Sylviidae. Harrison , C. & Greensmth , A. 1993. Birds of the World. Eyewitness Handbooks Hume , R. & Pearson , B. Seabirds. Martin , B. P. & Proud , A. 1993. Wildfowl of the British Isles and North-west Europe. Maclean , G.L. (ed.). 1993. Robert's Birds of Southern Africa. Mc Ferran , J.B. & Mc Nulty , M.S. (eds). Mc Gregor , P.K. (ed.). Mc Nicholl , K.M. & Cranmer -Byng , J.L. (eds). 1994. Ornithology in Ontario. Muñiz , A.M. & Rosello , E. (eds). 1993. Archaeornithology: Birds and the archaeological record. Archaeofauna (Revista de la Asociacion Española de Arqueozoología): 2. Norman , D. 1994. The Fieldfare. Ogilvie , M. & Pearson , B. 1994. Wildfowl Osing , H. 1993. Der Flußregenpfeifer (Charadrius dubius). Redig , P.T., Cooper , J.E., Remple , J.D. & Hunter Ryabitsev , V.K. 1993. Territorial Relationships and Bird Community Dynamics in the Subarctic (In Russian, English contents.) Schepers , F.J. & Marteijn , C.L. (eds). 1993. Coastal Waterbirds in Gabon. Smley , C.G. & Monroe , B.L., Jr . 1993. A Supplement to Distribution and Taxonomy of Birds of the World. Monroe , B.L., Jr . & Sibley , C.G. 1993. A World Checklist of Buds. Whylde , A. 1993. Threatened Mammals, Birds, Amphibians and Fish in Ireland. Irish Red Data Book 2: Vertebrates. Alderton , D. 1993. The Handbook of Cage and Aviary Birds. Boutin , J. 1993. Les Oiseaux de Camargue. Bransbury , J. 1992. Where to Find Birds in Australia. Camphuysen , C.J., Ensor , K., Furness , R.W., Garthe , S., Hüppop , O., Leaper , G., Offringer , H. & Tasker , M.L. 1993. Seabirds Feeding on Discards in Winter in the North Sea: Final report to the European Commission. Castroviejo , J. 1993. Mappa del Parque nacional de Doñana. Davis , S.M. & Ogden . J.C. (eds). 1994. Everglades: The ecosystem and its restoration. Department of the Environment . 1994. Biodiversity: The UK action plan. Epple , W. 1993. Eulen: Die geheimnisvollen Vagel der Nacht. Ken-nenlernen, erleben, schützen. Fernández -Cordeiro , A. & Dominguez , J. (eds). 1991. Actas do Pri-meiro Congreso Galego de Ornitoloxía. Cursos e Congressos da Universidade de Santiago de Compostela no. Finlayson , C.M., Chuikov , Y.S., Prentice , R.C. & Fischer , W. (eds). 1993. Biogeography of the Lower Volga. Russia: An overview. Fisher , C. & Jones , P. (eds). 1993. Papers from the History of Ornithology Conference Gales , R. 1993. Co-operative Mechanisms for the Conservation of Albatross. Garcia , E. & Paterson , A. 1994. Where to Watch Buds in Southern Spain, Andalucía. Extremadura and Gibraltar. Grishchenko , V.N. & Skil's‘kii , I.V. (eds). 1994. Materials of the 1st Conference of Young Ornithologists Ukraine, March 46.1994, Lutsk (in Russian). Library of journal “Berkut” 1. Holden , P. & Langman , M. 1994. Migrants and Migration. Kaufman , J. & Meng , H. 1992. Falcons Return. Keller , C.E. & Keller , T.C. 1993. Birds of Indianapolis: A guide to the region. Mc Eneaney , T. 1993. The Birder's Guide to Montana. Merritt , J.F. & Hannakan , C.J. (eds). 1992. Guide to Biological Field Stations: Directory of members Meschini , E. & Frugis , S. (eds). 1993. Atlante degli uccelli nidificanti in Italia. Supplemento alle Ricerche di Biologia deb Selvaggina. Nethercoat , I. & Langman , M. 1994. Bird Identification and Field Craft. Hamlyn Young Ornithologists' Guides Oman Bird Records Commitee . 1994. Oman Bird List. The official list of the birds of the Sultanate of Oman. Renno , K.O. (compiler). 1993. Eesti Linnutatlas: Eesti haudelindude levikuatlas. Sen -Hsiong Wu & Hsiou Yin Yang . 1991. A guide to the birds of Taiwan (in Chinese). Simpson , K. & Day , N. 1994. Field Guide to the Birds of Australia. The most complete one-volume book of identification. Thalmann , G. (ed.). 1994. Thorburn's Atlas of European Birds. Tomer , J.S. & Brodhead , M.J. (eds). 1992. A Naturalist in Indian Territory. The journals of S.W. Woodhouse, 1849–50. Watkins , D. 1993. A National Plan for Shorebird Conservation in Australia. Western Hemisphere Shorebird Reserve Network . 1993. Western Hemisphere Shorebird Reserve Network site profiles. World Conservation Monitoring Centre Cambridge Wynne , G. 1994. Biodiversity Challenge: An agenda for conservation action in the UK.     

Interaction between the oligomycin sensitivity conferring protein and the F0 sector of the mitochondrial adenosinetriphosphatase complex: cooperative effect of the F1 sector

Beef heart mitchondrial oligomycin sensitivity conferring protein (OSCP) labeled with [14C]-N-ethylmaleimide ([14C]OSCP) at the only cysteine residue, Cys-118, present in the sequence [Ovchinnikov, Y. A., Modyanov, N. N., Grinkevich, V. A., Aldanova, N. A., Trubetskaya, O. E., Nazimov, I.V., Hundal, T., & Ernster, L. (1984) FEBS Lett. 166, 19-22] exhibits full biological activity in a reconstituted F0-F1 system [Dupuis, A., Issartel, J. P., Lunardi, J., Satre, M., & Vignais, P. V. (1985) Biochemistry 24, 728-733]. The binding parameters of [14C]OSCP with respect to the F0 sector of submitochondrial particles largely depleted of F1 and OSCP (AUA particles) have been explored. In the absence of added F1, a limited number of high-affinity OSCP binding sites were detected in the AUA particles (20-40 pmol/mg of particles); under these conditions, the low-affinity binding sites for OSCP were essentially not saturable. Addition of F1 to the particles promoted high-affinity binding for OSCP, with an apparent Kd of 5 nM, a value 16 times lower than the Kd relative to the binding of OSCP to F1 in the absence of particles. Saturation of the F1 and OSCP binding sites of AUA particles was attained with about 200 pmol of both F1 and OSCP added per milligram of particles. The oligomycin-dependent inhibition of F1-ATPase bound to AUA particles was assayed as a function of bound OSCP. At subsaturating concentrations of F1, the dose-effect curves were rectilinear until inhibition of ATPase activity by oligomycin was virtually complete, and maximal inhibition was obtained for an OSCP to F1 ratio of 1 (mol/mol).(ABSTRACT TRUNCATED AT 250 WORDS)     

Normal fertilization occurs with eggs lacking the integrin alpha6beta1 and is CD9-dependent

Previous results, based on inhibition of fertilization by an anti-alpha6 integrin mAb (GoH3), suggest that the alpha6beta1 integrin on mouse eggs functions as the receptor for sperm (Almeida, E.A., A.P. Huovila, A.E. Sutherland, L.E. Stephens, P.G. Calarco, L. M. Shaw, A.M. Mercurio, A. Sonnenberg, P. Primakoff, D.G. Myles, and J.M. White. 1995. Cell. 81:1095-1104). Because the egg surface tetraspanin CD9 is essential for gamete fusion (Kaji, K., S. Oda, T. Shikano, T. Ohnuki, Y. Uematsu, J. Sakagami, N. Tada, S. Miyazaki, and A. Kudo. 2000. Nat. Genet. 24:279-282; Le Naour, F., E. Rubinstein, C. Jasmin, M. Prenant, and C. Boucheix. 2000. Science. 287:319-321; Miyado, K., G. Yamada, S. Yamada, H. Hasuwa, Y. Nakamura, F. Ryu, K. Suzuki, K. Kosai, K. Inoue, A. Ogura, M. Okabe, and E. Mekada. 2000. Science. 287:321-324) and CD9 is known to associate with integrins, recent models of gamete fusion have posited that egg CD9 acts in association with alpha6beta1 in fusion (Chen, M.S., K.S. Tung, S.A. Coonrod, Y. Takahashi, D. Bigler, A. Chang, Y. Yamashita, P.W. Kincade, J.C. Herr, and J.M. White. 1999. Proc. Natl. Acad. Sci. USA. 96:11830-11835; Kaji, K., S. Oda, T. Shikano, T. Ohnuki, Y. Uematsu, J. Sakagami, N. Tada, S. Miyazaki, and A. Kudo. 2000. Nat. Genet. 24:279-282; Le Naour, F., E. Rubinstein, C. Jasmin, M. Prenant, and C. Boucheix. 2000. Science. 287:319-321; Miyado, K., G. Yamada, S. Yamada, H. Hasuwa, Y. Nakamura, F. Ryu, K. Su- zuki, K. Kosai, K. Inoue, A. Ogura, M. Okabe, and E. Mekada. 2000. Science. 287:321-324). Using eggs from cultured ovaries of mice lacking the alpha6 integrin subunit, we found that the fertilization rate, fertilization index, and sperm binding were not impaired compared with wild-type or heterozygous controls. Furthermore, a reexamination of antibody inhibition, using an assay that better simulates in vivo fertilization conditions, revealed no inhibition of fusion by the GoH3 mAb. We also found that an anti-CD9 mAb completely blocks sperm fusion with either wild-type eggs or eggs lacking alpha6beta1. Based on these results, we conclude that the alpha6beta1 integrin is not essential for sperm-egg fusion, and we suggest a new model in which CD9 acts by itself, or interacts with egg protein(s) other than alpha6beta1, to function in sperm-egg fusion.     

Messenger RNA for the 73,000-dalton poly(A)-binding protein occurs as translationally repressed mRNP in duck reticulocytes

Poly(A)-containing mRNA has been prepared from the polyribosomes and post-polyribosomal mRNP fraction of duck reticulocytes. The coding capacity of the respective mRNA populations has been examined by translation in vitro followed by two-dimensional electrophoresis of the 35S-labeled polypeptides. A detailed analysis of these results is given elsewhere (Imaizumi-Scherrer, M.-T., Maundrell, K., Civelli, O., and Scherrer, K. (1982) Dev. Biol. 93, 126-138). Here, we focus on one of these translation products which migrates as a slightly basic protein of 73,000 molecular weight. By two-dimensional electrophoretic analysis and partial peptide mapping, we show that this protein is indistinguishable from the poly(A)-binding protein. We conclude that the majority of the coding sequences for this protein are translationally repressed in the reticulocyte cytoplasm.     

The thrombospondin motif of aggrecanase-1 (ADAMTS-4) is critical for aggrecan substrate recognition and cleavage

Aggrecanase-1 (ADAMTS-4) is a member of the a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS) protein family that was recently identified. Aggrecanase-1 is one of two ADAMTS cartilage-degrading enzymes purified from interleukin-1-stimulated bovine nasal cartilage (Tortorella, M. D., Burn, T. C., Pratta, M. A. , Abbaszade, I., Hollis, J. M., Liu, R., Rosenfeld, S. A., Copeland, R. A., Decicco, C. P., Wynn, R., Rockwell, A., Yang, F., Duke, J. L., Solomon, K., George, H., Bruckner, R., Nagase, H., Itoh, Y., Ellis, D. M., Ross, H., Wiswall, B. H., Murphy, K., Hillman, M. C., Jr., Hollis, G. F., and Arner, E.C. (1999) Science 284, 1664-1666; 2 Abbaszade, I., Liu, R. Q., Yang, F., Rosenfeld, S. A., Ross, O. H., Link, J. R., Ellis, D. M., Tortorella, M. D., Pratta, M. A., Hollis, J. M., Wynn, R., Duke, J. L., George, H. J., Hillman, M. C., Jr., Murphy, K., Wiswall, B. H., Copeland, R. A., Decicco, C. P., Bruckner, R., Nagase, H., Itoh, Y., Newton, R. C., Magolda, R. L., Trzaskos, J. M., and Burn, T. C. (1999) J. Biol. Chem. 274, 23443-23450). The aggrecan products generated by this enzyme are found in cartilage cultures stimulated with cytokines and in synovial fluid from patients with arthritis, suggesting that aggrecanase-1 may be important in diseases involving cartilage destruction. Here we demonstrate that the thrombospondin type-1 (TSP-1) motif located within the C terminus of aggrecanase-1 binds to the glycosaminoglycans of aggrecan. Data from several studies indicate that this binding of aggrecanase-1 to aggrecan through the TSP-1 motif is necessary for enzymatic cleavage of aggrecan. 1) A truncated form of aggrecanase-1 lacking the TSP-1 motif was not effective in cleaving aggrecan. 2) Several peptides representing different regions of the TSP-1 motif effectively blocked aggrecanase-1 cleavage of aggrecan by preventing the enzyme from binding to the substrate. 3) Aggrecanase-1 was not effective in cleaving glycosaminoglycan-free aggrecan. Taken together, these data suggest that the TSP-1 motif of aggrecanase-1 is critical for substrate recognition and cleavage.     

A molecular phylogeny of the cotingas (Aves: Cotingidae)

The phylogenetic relationships of members of Cotingidae were investigated using >2100 bp of sequence data from two nuclear introns (myoglobin intron 2 and G3PDH intron 11) and one protein-coding mitochondrial gene (cytochrome b). Strong support was found for a monophyletic clade including 23 traditional cotingid genera, corresponding to the Cotingidae sensu [Remsen, J.V. Jr., Jaramillo, A., Nores, M., Pacheco, J.F., Robbins, M.B., Schulenberg, T.S., Stiles, F.G., da Silva, J.M.C., Stotz, D.F., Zimmer, K.J., 2005. Version 2005-11-15. A classification of the bird species of South America. American Ornithologists' Union. ]. Neither Oxyruncus nor any of the genera in Tityrinae sensu [Prum, R.O, Lanyon, W.E., 1989. Monophyly and phylogeny of the Schiffornis group (Tyrannoidea). Condor 91, 444-461.] are members of Cotingidae. Within Cotingidae a polytomy of four well-supported clades was recovered: (1) the fruiteaters Pipreola and Ampelioides; (2) the Ampelion group, including Phytotoma; (3) Rupicola and Phoenicircus; and (4) the 'core cotingas' consisting of the remainder of the Cotingas (e.g. fruitcrows, Cotinga, Procnias, Lipaugus, and Carpodectes), with Snowornis in a basal position. The separation of Snowornis from Lipaugus [Prum, R.O, Lanyon, W.E., 1989. Monophyly and phylogeny of the Schiffornis group (Tyrannoidea). Condor 91, 444-461.] was strongly supported, as were the close relationships between Gymnoderus and Conioptilon, and between Tijuca and Lipaugus. However, basal relationships among 'core cotinga' clades were not resolved.     

The phylogenetic problem of Huia (Amphibia: Ranidae)

A taxonomic consensus for the diverse and pan-global frog family Ranidae is lacking. A recently proposed classification of living amphibians [Frost, D.R., Grant, T., Faivovich, J., Bain, R. H., Haas, A., Haddad, C.F.B., de Sá, R.O., Channing, A., Wilkinson, M., Donnellan, S.C., Raxworthy, C.J., Campbell, J.A., Blotto, B.L., Moler, P., Drewes, R.C., Nussbaum, R.A., Lynch, J.D., Green, D.M., Wheeler, W.C., 2006. The amphibian tree of life. B. Am. Mus. Nat. Hist. 297, 1-370] included expansion of the Southeast Asian ranid frog genus Huia from seven to 47 species, but without having studied the type species of Huia. This study tested the monophyly of this concept of Huia by sampling the type species and putative members of Huia. Molecular phylogenetic analyses consistently recovered the type species H. cavitympanum as the sister taxon to other Bornean-endemic species in the genus Meristogenys, rendering all previously published concepts of Huia as polyphyletic. Members of Huia sensu [Frost, D.R., Grant, T., Faivovich, J., Bain, R. H., Haas, A., Haddad, C.F.B., de Sá, R.O., Channing, A., Wilkinson, M., Donnellan, S.C., Raxworthy, C.J., Campbell, J.A., Blotto, B.L., Moler, P., Drewes, R.C., Nussbaum, R.A., Lynch, J.D., Green, D.M., Wheeler, W.C., 2006. The amphibian tree of life. B. Am. Mus. Nat. Hist. 297, 1-370.] appear in four places within the family Ranidae. A clade containing the type species of Odorrana is phylogenetically unrelated to the type species of Huia, and Odorrana is removed from synonymy with Huia. These findings underscore the need to include relevant type species in phylogenetic studies before proposing sweeping taxonomic changes. The molecular phylogenetic analyses revealed a high degree of homoplasy in larval and adult morphology of Asian ranid frogs. Detailed studies are needed to identify morphological synapomorphies that unite members in these major clades of ranid frogs.     

Role of the ortholog and paralog amino acid invariants in the active site of the UDP-MurNAc-L-alanine:D-glutamate ligase (MurD).

To evaluate their role in the active site of the UDP-N-acetylmuramoyl-L-alanine:D-glutamate ligase (MurD) from Escherichia coli, 12 residues conserved either in the Mur superfamily [Eveland, S. S., Pompliano, D. L., and Anderson, M. S. (1997) Biochemistry 36, 6223-6229; Bouhss, A., Mengin-Lecreulx, D., Blanot, D., van Heijenoort, J., and Parquet, C. (1997) Biochemistry 36, 11556-11563] or in the sequences of 26 MurD orthologs were submitted to site-directed mutagenesis. All these residues lay within the cleft of the active site of MurD as defined by its 3D structure [Bertrand, J. A., Auger, D., Fanchon, E., Martin, L., Blanot, D., van Heijenoort, J., and Dideberg, O. (1997) EMBO J. 16, 3416-3425]. Fourteen mutant proteins (D35A, K115A, E157A/K, H183A, Y194F, K198A/F, N268A, N271A, H301A, R302A, D317A, and R425A) containing a C-terminal (His)(6) extension were prepared and their steady-state kinetic parameters determined. All had a reduced enzymatic activity, which in many cases was very low, but no mutation led to a total loss of activity. Examination of the specificity constants k(cat)/K(m) for the three MurD substrates indicated that most mutations affected both the binding of one substrate and the catalytic process. These kinetic results correlated with the assigned function of the residues based on the X-ray structures.