The nucleocapsid protein of severe acute respiratory syndrome-coronavirus inhibits the activity of cyclin-cyclin-dependent kinase complex and blocks S phase progression in mammalian cells

Deregulation of the cell cycle is a common strategy employed by many DNA and RNA viruses to trap and exploit the host cell machinery toward their own benefit. In many coronaviruses, the nucleocapsid protein (N protein) has been shown to inhibit cell cycle progression although the mechanism behind this is poorly understood. The N protein of severe acute respiratory syndrome-coronavirus (SARS-CoV) bears signature motifs for binding to cyclin and phosphorylation by cyclin-dependent kinase (CDK) and has recently been reported by us to get phosphorylated by the cyclin-CDK complex (Surjit, M., Kumar, R., Mishra, R. N., Reddy, M. K., Chow, V. T., and Lal, S. K. (2005) J. Virol. 79, 11476-11486). In the present study, we prove that the N protein of SARS-CoV can inhibit S phase progression in mammalian cell lines. N protein expression was found to directly inhibit the activity of the cyclin-CDK complex, resulting in hypophosphorylation of retinoblastoma protein with a concomitant down-regulation in E2F1-mediated transactivation. Coexpression of E2F1 under such conditions could restore the expression of S phase genes. Analysis of RXL and CDK phosphorylation mutant N protein identified the mechanism of inhibition of CDK4 and CDK2 activity to be different. Whereas N protein could directly bind to cyclin D and inhibit the activity of CDK4-cyclin D complex; inhibition of CDK2 activity appeared to be achieved in two different ways: indirectly by down-regulation of protein levels of CDK2, cyclin E, and cyclin A and by direct binding of N protein to CDK2-cyclin complex. Down-regulation of E2F1 targets was also observed in SARS-CoV-infected VeroE6 cells. These data suggest that the S phase inhibitory activity of the N protein may have major significance during viral pathogenesis.     

The complete amino acid sequence of coagulogen isolated from Southeast Asian horseshoe crab, Carcinoscorpius rotundicauda

The complete amino acid sequence of coagulogen purified from the hemocytes of the horseshoe crab Carcinoscorpius rotundicauda was determined by characterization of the NH2-terminal sequence and the peptides generated after digestion of the protein with lysyl endopeptidase, Staphylococcal aureus protease V8 and trypsin. Upon sequencing the peptides by the automated Edman method, the following sequence was obtained: A D T N A P L C L C D E P G I L G R N Q L V T P E V K E K I E K A V E A V A E E S G V S G R G F S L F S H H P V F R E C G K Y E C R T V R P E H T R C Y N F P P F V H F T S E C P V S T R D C E P V F G Y T V A G E F R V I V Q A P R A G F R Q C V W Q H K C R Y G S N N C G F S G R C T Q Q R S V V R L V T Y N L E K D G F L C E S F R T C C G C P C R N Y Carcinoscorpius coagulogen consists of a single polypeptide chain with a total of 175 amino acid residues and a calculated molecular weight of 19,675. The secondary structure calculated by the method of Chou and Fasman reveals the presence of an alpha-helix region in the peptide C segment (residue Nos. 19 to 46), which is released during the proteolytic conversion of coagulogen to coagulin gel. The beta-sheet structure and the 16 half-cystines found in the molecule appear to yield a compact protein stable to acid and heat. The amino acid sequences of coagulogen of four species of limulus have been compared and the interspecies evolutionary differences are discussed.     

Decreasing Tropomyosin Phosphorylation Rescues Tropomyosin-induced Familial Hypertrophic Cardiomyopathy

Studies indicate that tropomyosin (Tm) phosphorylation status varies in different mouse models of cardiac disease. Investigation of basal and acute cardiac function utilizing a mouse model expressing an α-Tm protein that cannot be phosphorylated (S283A) shows a compensated hypertrophic phenotype with significant increases in SERCA2a expression and phosphorylation of phospholamban Ser-16 (Schulz, E. M., Correll, R. N., Sheikh, H. N., Lofrano-Alves, M. S., Engel, P. L., Newman, G., Schultz Jel, J., Molkentin, J. D., Wolska, B. M., Solaro, R. J., and Wieczorek, D. F. (2012) J. Biol. Chem. 287, 44478–44489). With these results, we hypothesized that decreasing α-Tm phosphorylation may be beneficial in the context of a chronic, intrinsic stressor. To test this hypothesis, we utilized the familial hypertrophic cardiomyopathy (FHC) α-Tm E180G model (Prabhakar, R., Boivin, G. P., Grupp, I. L., Hoit, B., Arteaga, G., Solaro, R. J., and Wieczorek, D. F. (2001) J. Mol. Cell. Cardiol. 33, 1815–1828). These FHC hearts are characterized by increased heart:body weight ratios, fibrosis, increased myofilament Ca²⁺ sensitivity, and contractile defects. The FHC mice die by 6–8 months of age. We generated mice expressing both the E180G and S283A mutations and found that the hypertrophic phenotype was rescued in the α-Tm E180G/S283A double mutant transgenic animals; these mice exhibited no signs of cardiac hypertrophy and displayed improved cardiac function. These double mutant transgenic hearts showed increased phosphorylation of phospholamban Ser-16 and Thr-17 compared with the α-Tm E180G mice. This is the first study to demonstrate that decreasing phosphorylation of tropomyosin can rescue a hypertrophic cardiomyopathic phenotype.     

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.     

Book Reviews

Wilkinson, R. E. (ed.) Plant-Environment Interactions, Second Edition.
Stacey, G.; Keen, N. T. (eds) : Plant-Microbe Interactions.
Shurtle, M. C.; C. W. Averre Ill : Diagnosing Plant Diseases Caused by Nematodes.
Tjamos, E. C., R. C. Rowe, J. B. Heale, D. R. Fravel (eds) : Advances in Verticillium: Research and Disease Management.
Frederiksen, R. A.; G. N. Odvody (eds) : Compedium of Sorghum Diseases.
Podila, G. K., D. D. Douds Jr. (eds) : Current Advances in Mycorrhizae Research.
Kronstad, J. W. (ed.) : Fungal Pathology.
Agrawal, A. A., S. Tuzun, E. Bent (eds) : Induced Plant Defenses against Pathogens and Herbivores. Biochemistry, Ecology, and Agriculture.
Bartels, G.; Backhaus, G. F. (Hrg.) : Die Pr̈ng von Panzen auf ihre Widerstandsfhigkeit gegen Schadorganismen in der Biologischen Bundesanstalt. Teil 2 Resistenzpr̈ng von Kulturpanzen im Acker- und Gartenbau gegen Pilze, Bakterien und Viren-Testing of crop cultivars for resistance to noxious organisms at the Federal Biological Research Centre. Part 2. Testing of resistance of field and horticultural crops to fungi, bacteria and viruses. Mitt. Biol. Bundesanstalt för Land- und Forstwirtschaft, Berlin-Dahlem, Heft 373.
Bacon, Ch. W., L. F. White Jr. (eds) : Microbial Endophytes.
Siddiqi, M. R. : Tylenchida. Parasites of Plants and Insects.
Khetan, S. K. : Microbial Pest Control.
Upadhyay, R. K., K. G. Mukerji, B. P. Chamola (eds) : Biocontrol Potential and its Exploitation in Sustainable Agriculture.     

Book Reviews

Books review in this article:
The Biochemical Basis of Neuropharmacology (5th edition) by J. R. Cooper, F. E. Bloom, and R. H. Roth
Animal Cell Culture, a Practical Approach by R. I. Freshney
Folates and Pterins. Nutritional Pharmacological and Physiological Aspects , Vol. 3 edited by R. L. Blakley and V. M. Whitehead
MPTP: A Neurotoxin Producing a Parkinsonian Syndrome edited by S. P. Markey, N. Castagnoli Jr., A. J. Trevor, and I. J. Kopin
GABAergic Mechanisms in the Mammalian Periphery edited by S. L. Erdö and N. G. Bowery     

The hereditary hemochromatosis protein, HFE, specifically regulates transferrin-mediated iron uptake in HeLa cells

HFE is the protein product of the gene mutated in the autosomal recessive disease hereditary hemochromatosis (Feder, J. N., Gnirke, A., Thomas, W., Tsuchihashi, Z., Ruddy, D. A., Basava, A., Dormishian, F., Domingo, R. J., Ellis, M. C., Fullan, A., Hinton, L. M., Jones, N. L., Kimmel, B. E., Kronmal, G. S., Lauer, P., Lee, V. K., Loeb, D. B., Mapa, F. A., McClelland, E., Meyer, N. C., Mintier, G. A., Moeller, N., Moore, T., Morikang, E., Prasss, C. E., Quintana, L., Starnes, S. M., Schatzman, R. C., Brunke, K. J., Drayna, D. T., Risch, N. J., Bacon, B. R., and Wolff, R. R. (1996) Nat. Genet. 13, 399-408). At the cell surface, HFE complexes with transferrin receptor (TfR), increasing the dissociation constant of transferrin (Tf) for its receptor 10-fold (Gross, C. N., Irrinki, A., Feder, J. N., and Enns, C. A. (1998) J. Biol. Chem. 273, 22068-22074; Feder, J. N., Penny, D. M., Irrinki, A., Lee, V. K., Lebron, J. A., Watson, N. , Tsuchihashi, Z., Sigal, E., Bjorkman, P. J., and Schatzman, R. C. (1998) Proc. Natl. Acad. Sci. U S A 95, 1472-1477). HFE does not remain at the cell surface, but traffics with TfR to Tf-positive internal compartments (Gross et al., 1998). Using a HeLa cell line in which the expression of HFE is controlled by tetracycline, we show that the expression of HFE reduces 55Fe uptake from Tf by 33% but does not affect the endocytic or exocytic rates of TfR cycling. Therefore, HFE appears to reduce cellular acquisition of iron from Tf within endocytic compartments. HFE specifically reduces iron uptake from Tf, as non-Tf-mediated iron uptake from Fe-nitrilotriacetic acid is not altered. These results explain the decreased ferritin levels seen in our HeLa cell system and demonstrate the specific control of HFE over the Tf-mediated pathway of iron uptake. These results also have implications for the understanding of cellular iron homeostasis in organs such as the liver, pancreas, heart, and spleen that are iron loaded in hereditary hemochromatotic individuals lacking functional HFE.     

Books

Books reviewed in this article:
BROMHALL, D. 1980. Devil birds: the life of the Swift.
HAMMOND, N. & EVERETT, M. 1980. Birds of Britain and Europe.
H osking , E. & M ac D onell , K. 1980. Eric Hosking's birds
H oward , R. & M oore , A. 1980. A complete checklist of the birds of the world
K ovshar' , A. F. 1979. (Songbirds in the subalpine zone of Tien-shan.)
L y -T io -F ane , M. 1978 ('1976'). Pierre Sonnerat 1748–1814. An account of his life and work
M oon , G. 1980. The birds around us: New Zealand birds, their habits and habitats
N isbet , I. C. T. 1980. Status and trends of the Roseate Tern Sterna dougallii in North America and the Caribbean
N orth -C oombes , A. 1980 ('1979'). The vindication of Frangois Leguat
P emberton , J. E. 1980. The birdwatcher's yearbook
S kutch , A. F. 1979. The imperative call: a naturalist's quest in temperate and tropical America
S tonehouse , B. (ed.) 1978. Animal marking. Recognition marking of animals in research
S utcliffe , S. A. (ed.) 1979. Proceedings of the Second North American Conference on Common Loon Research and Management
C arp , E. 1980. Dictionary of wetlands of international importance in the western Palearctic
C lark , R. J., S mith , D. G. & K elso , L. H. 1978. Working bibliography of the owls of the world
C ortes , J. E., F inlayson , J. C., M osquera , M. A. & G arcia , E. F. J. 1980. The birds of Gibraltar
F alkus , H. 1980. Nature detective
L incer , J. L., C lark , W. S. & L e F ranc , M. N. 1979. Working bibliography of the Bald Eagle
L ockley , R. M. 1980. Orielton: the human and natural history of a Welsh Manor
P aine , A. J. R. Birds of prey in Suffolk 1973–78
P hillips , W. W. A. 1978. Annotated checklist of the birds of Ceylon (Sri Lanka)     

Role of alpha-helix seven of Bacillus thuringiensis Cry1Ab delta-endotoxin in membrane insertion, structural stability, and ion channel activity

Domain I of the Cry1Ab insecticidal toxic protein has seven alpha-helices and is considered to be involved in the ion channel activity. While other alpha-helices, particularly alpha-4 and alpha-5, have been extensively explored, the remaining alpha-helices have been slightly studied. Site-directed mutagenesis was used to generate mutations throughout sequences encoding the alpha-helix 7 to test its role in ion channel function. Every amino acid residue in alpha-helix 7 was mutated to alanine. Most resultant proteins, e.g., D225A, W226A, Y229A, N230A, R233A, R234A, D242A, and F247A yielded no protoxin or were sensitive to degradation by trypsin or Manduca sexta midgut juice. Other mutant proteins, R224A, R228A, and E235A, were resistant to degradation to the above proteases but were 8, 30, and 12 times less toxic to M. sexta, respectively, than the wild-type Cry1Ab. Circular dichroism spectroscopy indicated a very small change in the R228A spectrum, while R224A and E235A display the same spectrum as the wild-type protein. These three mutant proteins showed little differences from Cry1Ab when analyzed by saturation binding and competition binding kinetics with (125)I-labeled toxin or by surface plasmon resonance to M. sexta brush border membrane vesicles. More conservative amino acid substitutions were introduced into alpha-helix 7 residues: R228K, F232Y, E235Q, and F247Y. In comparison with wild-type Cry1Ab, mutant proteins R228K, F232Y, E235A, and E235Q selectively discriminate between K+ and Rb+, while R224A and R228A had reduced inhibition of short-circuit current for both ions, when analyzed by voltage clamping of M. sexta midguts.     

Mechanism of inhibition of HIV-1 integrase by G-tetrad-forming oligonucleotides in Vitro

The G-tetrad-forming oligonucleotides and have been identified as potent inhibitors of human immunodeficiency virus type 1 integrase (HIV-1 IN) activity (Rando, R. F., Ojwang, J., Elbaggari, A., Reyes, G. R., Tinder, R., McGrath, M. S., and Hogan, M. E. (1995) J. Biol. Chem. 270, 1754-1760; Mazumder, A., Neamati, N., Ojwang, J. O., Sunder, S., Rando, R. F., and Pommier, Y. (1996) Biochemistry 35, 13762-13771; Jing, N., and Hogan, M. E. (1998) J. Biol. Chem. 273, 34992-34999). To understand the inhibition of HIV-1 IN activity by the G-quartet inhibitors, we have designed the oligonucleotides and, composed of three and four G-quartets with stem lengths of 19 and 24 A, respectively. The fact that increasing the G-quartet stem length from 15 to 24 A kept inhibition of HIV-1 IN activity unchanged suggests that the binding interaction occurs between a GTGT loop domain of the G-quartet inhibitors and a catalytic site of HIV-1 IN, referred to as a face-to-face interaction. Docking the NMR structure of (Jing and Hogan (1998)) into the x-ray structure of the core domain of HIV-1 IN, HIV-1 IN-(51-209) (Maignan, S., Guilloteau, J.-P. , Qing, Z.-L., Clement-Mella, C., and Mikol, V. (1998) J. Mol. Biol. 282, 359-368), was performed using the GRAMM program. The statistical distributions of hydrogen bonding between HIV-1 IN and were obtained from the analyses of 1000 random docking structures. The docking results show a high probability of interaction between the GTGT loop residues of the G-quartet inhibitors and the catalytic site of HIV-1 IN, in agreement with the experimental observation.     

In vivo studies of altered expression patterns of p53 and proliferative control genes in chronic vitamin A deficiency and hypervitaminosis.

Several clinical trials have revealed that individuals who were given beta-carotene and vitamin A did not have a reduced risk of cancer compared to those given placebo; rather, vitamin A could actually have caused an adverse effect in the lungs of smokers [Omenn, G.S., Goodman, G.E., Thornquist, M.D., Balmes, J., Cullen, M.R., Glass, A., Keogh, J.P., Meyskens, F.L., Valanis, B., Williams, J.H., Barnhart, S. & Hammar, S. N. Engl. J. Med (1996) 334, 1150-1155; Hennekens, C.H., Buring, J.E., Manson, J.E., Stampfer, M., Rosner, B., Cook, N.R., Belanger, C., LaMotte, F., Gaziano, J.M., Ridker, P.M., Willet, W. & Peto, R. (1996) N. Engl. J. Med. 334, 1145-1149]. Using differential display techniques, an initial survey using rats showed that liver RNA expression of c-H-Ras was decreased and p53 increased in rats with chronic vitamin A deficiency. These findings prompted us to evaluate the expression of c-Jun, p53 and p21WAF1/CIF1 (by RT-PCR) in liver and lung of rats. This study showed that c-Jun levels were lower and that p53 and p21WAF1/CIF1 levels were higher in chronic vitamin A deficiency. Vitamin A supplementation increased expression of c-Jun, while decreasing the expression of p53 and p21WAF1/CIF1. Western-blot analysis demonstrated that c-Jun and p53 showed a similar pattern to that found in the RT-PCR analyses. Binding of retinoic acid receptors (RAR) to the c-Jun promoter was decreased in chronic vitamin A deficiency when compared to control hepatocytes, but contrasting results were found with acute vitamin A supplementated cells. DNA fragmentation and cytochrome c release from mitochondria were analyzed and no changes were found. In lung, an increase in the expression of c-Jun produced a significant increase in cyclin D1 expression. These results may explain, at least in part, the conflicting results found in patients supplemented with vitamin A and illustrate that the changes are not restricted to lung. Furthermore, these results suggest that pharmacological vitamin A supplementation may increase the risk of adverse effects including the risk of oncogenesis.     

REVIEWS

Book reviewed in this article
Plant Physiology. By N. A. M aximov , edited by R. B. H arvey and A. E. M urneek .
The Physiology of Plants. By W illiam S eifriz .
A Textbook of General Botany. By R. M. H olman and W. W. R obbins .
Plant Form and Function. By F. E. F ritsch and E. J. S alisbury .
Plant Physiology, with Reference to the Green Plant. By E. C. M iller , Ph.D.
The Vegetation of South Africa. By R. S. A damson , M.A., D.Sc.     

Amino acid sequence and post-translational modification of stem cell factor isolated from buffalo rat liver cell-conditioned medium.

Stem cell factor (SCF) isolated from culture medium conditioned by Buffalo rat liver cells was subjected to detailed structural analysis. Attempts at direct N-terminal sequencing of the factor indicated that its N terminus is blocked as pyroglutamic acid (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., Bosselman, R. A., Mendiaz, E. A., and Langley, K. E. (1990) Cell 63, 195-201). The removal of the blocking pyroglutamate by pyroglutamate aminopeptidase allowed sequencing of the polypeptide chain to position 47. Stem cell factor was also digested with CNBr, trypsin, Staphylococcus aureus protease (strain V8), and AspN peptidase to generate different sets of peptides that were then separated by reverse-phase high-performance liquid chromatography and sequenced. Sequence of an internal peptide fragment obtained by cleavage of stem cell factor at a single tryptophanyl peptide bond was also obtained. From these analyses, the complete amino acid sequence could be constructed. The factor as isolated is a single polypeptide of 164 or 165 amino acids. The sequence is confirmatory to a sequence deduced from a cDNA sequence and provides important evidence for C-terminal processing of the polypeptide encoded by cDNA. There are four potential N-linked glycosylation sites. Asn65, Asn72, Asn109, and Asn120. Sequence determination of isolated peptides suggested that Asn120 is glycosylated, Asn65 and Asn109 glycosylated in some molecules but not in others, and Asn72 not glycosylated. Amino acids at three positions, i.e. 142, 143, and 155, could not be detected during sequence analysis. Since the gene sequence codes for Ser, Thr, and Thr at these positions (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. C., 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. W., Cupples, R. L., and Zsebo, K. M. (1990) Cell 63, 203-211), they could be sites of O-linked carbohydrate attachment. The four cysteines form two intramolecular disulfide bonds, Cys4-Cys89 and Cys43-Cys138.     

KIF14 and citron kinase act together to promote efficient cytokinesis

Multiple mitotic kinesins and microtubule-associated proteins (MAPs) act in concert to direct cytokinesis (Glotzer, M. 2005. Science. 307:1735-1739). In anaphase cells, many of these proteins associate with an antiparallel array of microtubules termed the central spindle. The MAP and microtubule-bundling protein PRC1 (protein-regulating cytokinesis 1) is one of the key molecules required for the integrity of this structure (Jiang, W., G. Jimenez, N.J. Wells, T.J. Hope, G.M. Wahl, T. Hunter, and R. Fukunaga. 1998. Mol. Cell. 2:877-885; Mollinari, C., J.P. Kleman, W. Jiang, G. Schoehn, T. Hunter, and R.L. Margolis. 2002. J. Cell Biol. 157:1175-1186). In this study, we identify an interaction between endogenous PRC1 and the previously uncharacterized kinesin KIF14 as well as other mitotic kinesins (MKlp1/CHO1, MKlp2, and KIF4) with known functions in cytokinesis (Hill, E., M. Clarke, and F.A. Barr. 2000. EMBO J. 19:5711-5719; Matuliene, J., and R. Kuriyama. 2002. Mol. Biol. Cell. 13:1832-1845; Kurasawa, Y., W.C. Earnshaw, Y. Mochizuki, N. Dohmae, and K. Todokoro. 2004. EMBO J. 23:3237-3248). We find that KIF14 targets to the central spindle via its interaction with PRC1 and has an essential function in cytokinesis. In KIF14-depleted cells, citron kinase but not other components of the central spindle and cleavage furrow fail to localize. Furthermore, the localization of KIF14 and citron kinase to the central spindle and midbody is codependent, and they form a complex depending on the activation state of citron kinase. Contrary to a previous study (Di Cunto, F., S. Imarisio, E. Hirsch, V. Broccoli, A. Bulfone, A. Migheli, C. Atzori, E. Turco, R. Triolo, G.P. Dotto, et al. 2000. Neuron. 28:115-127), we find a general requirement for citron kinase in human cell division. Together, these findings identify a novel pathway required for efficient cytokinesis.     

THE EVOLUTION OF THE CONIFER CONE

Die Koniferen des Oberkarbons und des unteren Perms , Parts 1–7. By R udolf F lorin .
Plant Life of the Pacific World. By E lmer D. M errill
Merrilleana , A Selection from the General Writings of E lmer D rew M errill , Sc.D., LL.D.
Forest Soils and Forest Grozuth. By S. A. W ilde , F.E., D.T ech .S c .
The Natural Vegetation of Trinidad. By J. S. B eard .
Dating the Past: An Introduction to Geochronology. By F rederick E. Z euner .
La Culture des Tissits. By R.-J. G autheret .     

REVIEWS

Book review in this article
Botanical Latin . By W. T. S tearn .
Laboratory Manual of Tropical Mycology and Elementary Bacteriology . By A. T hompson and G loria L im .
Agriculture in the Tropics . By C. C. W ebster and P. N. W ilson .
Bananas . By N. W. S immonds .
Rice . By D. H. G rist .
Tea . By T. E den .
Lowson's Botany . By E. W. S imon , K. J. D ormer and J. N. H artshorne .
Annual Review of Plant Physiology , Vol. 16. Ed. by L. M achlis and W. K. B riggs .
Ultrastructural Plant Cytology . By A. F rey -W yssling and K. M ühlethaler .
Drawings of British Platits . Part XXII, Scrophulariaceae (1). By S tella R oss
Molecules and Cells .By D. A. C oult . The Principles of Modern Biology. Ed. by D. A. C oult .
The Growth of Cereals and Grasses . Ed. by F. L. M ilthorpe and J. D. I vins .
Origins of Metidelism . By R. C. O lby .
Fungal Genetics . By J. R. S. F incham and P. R. D ay . Botanical Monographs, Vol. 4, ed. by W. O. J ames .
Genetik der Pilze . by K. E sser and R. K uenen .
Microbial and Molecular Genetics . By J. R. S. F incham . Modern Biology Series, ed. by J. E. W ebb .
Index Kewensis Plantarum Phanerogamarum, Supplementum XIII . Compiled at the Herbarium of the Royal Botanic Gardens, Kew, under the direction of Sir G eorge T aylor .
A Flora of Northeastern Minnesota . By O lga L akela .
Stephen Hales, D.D., F.R.S. An Eighteenth Century Biography . By A. E. C lark -K ennedy .     

The complete amino acid sequence of the low molecular weight cytosolic acid phosphatase

This paper presents the complete amino acid sequence of the low molecular weight acid phosphatase from bovine liver. This isoenzyme of the acid phosphatase family is located in the cytosol, is not inhibited by L-(+)-tartrate and fluoride ions, but is inhibited by sulfhydryl reagents. The enzyme consists of 157 amino acid residues, has an acetylated NH2 terminus, and has arginine as the COOH-terminal residue. All 8 half-cystine residues are in the free thiol form. The molecular weight calculated from the sequence is 17,953. The sequence was determined by characterizing the peptides purified by reverse-phase high performance liquid chromatography from tryptic, thermolytic, peptic, Staphylococcus aureus protease, and chymotryptic digests of the carboxymethylated protein. No sequence homologies were found with the two known acylphosphatase isoenzymes or the metalloproteins porcine uteroferrin and purple acid phosphatase from bovine spleen (both of which have acid phosphatase activity). Two half-cystines at or near the active site were identified through the reaction of the enzyme with [14C] iodoacetate in the presence or in the absence of a competitive inhibitor (i.e. inorganic phosphate). Ac-A E Q V T K S V L F V C L G N I C R S P I A E A V F R K L V T D Q N I S D N W V I D S G A V S D W N V G R S P N P R A V S C L R N H G I N T A H K A R Q V T K E D F V T F D Y I L C M D E S N L R D L N R K S N Q V K N C R A K I E L L G S Y D P Q K Q L I I E D P Y Y G N D A D F E T V Y Q Q C V R C C R A F L E K V R-OH.     

Recent ornithological publications

UK Raptor Wording Group Armstrong , P. The English Country Parson: A companionship between Science and Religion. Berry , R. J. Orkney Nature. Bibby , C. J., Burgess , N.D., Hill , D.A. & Mustoe , S.H. Bird Census Techniques Böhm , C. Die Wasserpieper: Vom Meeresstrand zum Gletscherrand. Brewer , D., Diamond , A., Woodsworth , E.J., Collins , B.T. & Dunn , E.H. Canadian Atlas of Bird Banding. Volume 1: Doves, Cuckoos, and Hummingbirds through Passerines Chapman , A, The Hobby. Chiappe , L.M., Sh'uan , J., Qiang , J. & Norell , M.A. Anatomy and Systematics of the Confucius‐ornithidae (Theropoda: Aves) from the Late Mesozoic of Northeastern China. Coro Arizmendi , M. & Marquez Valdelamar , L. (eds) Areas de importancia para la Conservación de las Aves en MéAxico. Dean , W.R.J. The Birds of Angola. dolling , R.J., Fay , R.R. & Popper , A.N. (eds) Comparative Hearing: Birds and Reptiles. Elias , G. L., Reino , L. M., Silva , T., Tome , R. & Geraldes , P. Atlas das Aves Invernantes do Baixo Alentejo. Fry , C.H., Keith , S. & Urban , E.K. (eds) Birds of Africa Volume 6. Harris , T. & Franklin , K. Shrikes and Bush‐shrikes; including wood‐shrikes, helmet‐shrikes, flycatchershrikes, philentomas, batises and wattle‐eyes. Johnsgard , P.A. Trogons and Quetzals of the World. Lenz , N. Evolutionary Ecology of the Regent Bowerbird Sericulus chrysocephalus (Lewin, 1808). Olney , P.J.S., & Fisken , F.A. (eds) International Zoo Yearbook, Vol.37. Petersen , Islenskir Fuglar (Icelandic Birds) (in Icelandic). Robb, M.S. Introcuction to Vocalizations of Crossbills in North‐western Europe. Rodner , C., Lentino , M., & Restall , R. Checklist of the Birds of Nortehrn South America: an annotated checklist of the species and subspecies of Ecuador, Colombia, Venezuela, Aruba, Curaçao, Bonaire, Trinidad & Tobago, Guyana, Suriname and French Guiana. Sayre , R., Roca , E., Sedaghatkish , G., Young , B., Keel , S., Roca , R. & Shepparo , S. Nture n Focus: Rapid Ecological Assessment. Schulze ‐Hagen , K. & Geus , A. Joseph Wolf. Shawyer , C., Clarke , R. & Dixon , N. A Study into the Raptor Predation of Domestic Pigeons. Sibley , D. The North American Bird Guide. Siokhin , V.D. (ed.) Chislennost' i razmeshchenie gneziashchikhia okolovodnykh ptits v vodno‐bolotnykh ugodiakh Azovo‐Chernomorskogo poberezhia Ukrainy [Numbers and Distribution of Breeding Waterbirds in the Wetlands of the Azov‐Black Sea Region of Ukraine] (in Russian, with English summaries and captions). Skutch , A.F. Harmony and Conflict in the Living World. Snyder , N., Mc Gowan , P., Gilardi , J., & Grajal , A. (eds) Parrots. Status Survey and Conservation Action Plan 2000–2004. Storch , I. Status Survey and Conservation Action Plan 2000–2004: Grouse. Tamisier , A. & Dehorter , O. Camargue, Canards et Foulques. Tickell , W.L.N. Albatrosses. Vickery , P.D. & Herkert , R. (eds) Ecology and Conservation of Grassland Birds in the Western Hemisphere. Wilcove , D.S. The Condor's Shadow. The Loss and Recovery of Wildlife in America. Chamberlain , D.E., Fuller , R.J., Shrubb , M. Bunce , R.G.H., Duckworth , J.C, Garthwaite , D.G., Impey , A.J. & Hart , A.D.M. The Effects of Agricultural Management on Farmland Birds. Datskevich , V.A. Istoricheskii ocherk i nekotorye itogi ornitologicheskikh issledovanii v Belovezhskoi pushche (1945–1985 gg.) [Historical Survey and some Results of Ornithological Studies in the Belovezhskaya Pushcha (1945–1985)]. Fesenko , G.V. & Bokotey , A.A. Anotovanii spisok ukraînskikh naukovikh nazv ptakhiv fauni Ukraîni [The Annotated List of the Ukrainian Scientific Names of the Bird Species belonging to the Fauna of Ukraine] (in Ukrainian). Oddie , B. Bill Oddie's Birding Map of Britain & Ireland, 2nd edn. Pemberton , J.E. (ed.) The Birdwatcher's Yearbook and Diary 2001. Rusev , I.T. (ed.) Ptitsy Azovo‐Chernomorskogo regiona na rubezhe tysiacheletil: materialy iubileinoi mezhdunarodnoi nauchnoi konferentsii, posviashchennoi 20‐letiu Azovo Chernomorskoi ornitologicheskoi rabochei gruppy, Odessa 10–14 febralia 2000g [Birds of Black Sea Region on Border of Millenium] Serebryakov , V.V. & Alekseyenko , V.R. Vodno‐bolotnye ugod'ia Azovo‐Chernomorskogo poberezh'ia Ukrainy, bibliograficheskii ukazatel' 1970–1999 [Wetlands of the Azov‐Black Sea Region of Ukraine: Bibliography 1970–19991 (in Russian and English). Symanski , R. Blackhearts: Ecology in Outback Australia. World Conservation Monitoring Centre . Checklist of CITES Species: a Reference to the Appendices to the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Chappuis , C. Oiseaux d'Afrique. African Bird Sounds.     

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.