Isolation and sequencing of cDNA clones encoding Drosophila chromosomal protein D1. A repeating motif in proteins which recognize at DNA

Drosophila melanogaster D1 is a satellite DNA-associated protein which preferentially binds DNA sequences containing runs of AT base pairs. Clones encoding this polypeptide have been isolated from a lambda gt11 cDNA library by immunological screening with a D1 antiserum. The deduced sequence of the D1 polypeptide is 355 amino acids long and contains 10 copies of a repeating motif consisting of a glycine-arginine-proline (GRP) tripeptide located within a cluster of basic amino acids. Three copies of a similar motif have previously been observed in a mammalian satellite DNA-binding protein, high mobility group protein I (Lund, T., Dahl, K. H., Mork, E., Holtlund, J., and Laland, S. G. (1987) Biochem. Biophys. Res. Commun. 146, 725-730), suggesting that this motif may be a general feature of proteins which bind AT-rich satellite DNA and perhaps other AT-containing DNA as well.     

New and interesting cases of conjugating desmids from Lapland

A number of desmid samples collected in Lapland appeared to be remarkably rich in zygospores. The spore morphology of Euastrum sinuosum Lenorm. ex Arch., Cosmarium tumidum Lund., C. isthmochondrum Nordst., Staurastrum dilatatum Ehr. ex Ralfs, Actinotaenium wollei (W. & G. S. West) Teil. ex Růž. & Pouz. and A. didymocarpum (Lund.) comb, nov., either when hitherto unknown or requiring a critical discussion is extensively treated. A new species, Cosmarium taxillus (with zygospores) is described.
Repeatedly recorded incidences of a disturbed zygospore development and the grey to black pigmentation of the mesosporium are discussed in connection with the possible effect of habitat factors.     

Low-resolution structure of the complex of human blood platelet factor 4 with heparin determined by small-angle neutron scattering

Small-angle neutron scattering was used to confirm that human platelet factor 4 was a compact tetrameric globular protein of radius of gyration 1.74 nm and indistinguishable from a sphere. The same technique, when applied to the 1:1 mol/mol complex of platelet factor and heparin of Mr 14000, revealed that the radius of gyration of the particle varied, depending on the relative proportion of 2H2O to H2O in the solvent. Analysis of this variation by the method of Ibel and Stuhrmann (Ibel, K. and Stuhrmann, H.B. (1975) J. Mol. Biol. 93, 255-266) revealed that in the complex the material of greatest neutron-scattering length (the highly sulphated polysaccharide heparin) was furthest from the centre of the particle. This confirms the postulate of Luscombe and Holbrook (Luscombe, M. and Holbrook, J.J. (1983) in Glycoconjugates (Chester, A.M., Heineg?rd, D., Lundblad, A. and Svensson, S., eds.), pp. 818-819, Secretariat, Lund) that the exact 1:1 mole ratio of heparin (Mr greater than 10 000) to platelet factor in this stable complex arises from the heparin winding around the outside of a globular protein core.     

Promotion of the in vitro renaturation of dodecameric glutamine synthetase from Escherichia coli in the presence of GroEL (chaperonin-60) and ATP.

The folding and assembly of dodecameric glutamine synthetase (GS) from Escherichia coli was examined in the absence and presence of the E. coli heat shock protein, GroEL (chaperonin-60). At nonphysiological temperatures (15-20 degrees C), unfolded GS spontaneously renatured to 80-90% of its original activity in the absence of GroEL. At near-physiological temperatures (37 degrees C), only 20-40% of the original activity returns. Under the latter solution conditions, GroEL and ATP enhance the extent of GS renaturation to 70-80% of the original activity at 37 degrees C. In the absence of ATP, GroEL arrests the renaturation of unfolded GS by forming a stable binary complex. The addition of ATP to this complex resulted in the release of GS subunits and formation of active dodecameric GS. The order of addition of ATP or unfolded GS to GroEL results in differences in the t1/2 values where half-maximal GS activity is attained. At a constant GS concentration, the formation of the GroEL.GS complex followed by ATP addition resulted in approximately a 2-fold increase in the observed t1/2 value compared to that observed when GroEL was preincubated with ATP before the GS renaturation reaction was initiated. These differences in renaturation rates may be related to binding affinity differences between the ATP-free and -bound GroEL conformer for unfolded or partially folded protein substrates [Badcoe, I. G., Smith, C. J., Wood, S., Halsall, D. J., Holbrook, J. J., Lund, P., & Clarke, A. R. (1991) Biochemistry 30, 9195-9200].(ABSTRACT TRUNCATED AT 250 WORDS)     

Force of Habit: Exploring Everyday Culture

Force of Habit: Exploring Everyday Culture. Jonas Frykman and Orvar Lofgren. eds. Lund Studies in European Ethnology, 1. Lund, Sweden: Lund University Press, 1996. 172 pp.     

Human U1 small nuclear RNA pseudogenes do not map to the site of the U1 genes in 1p36 but are clustered in 1q12-q22.

Human U1 small nuclear RNA is encoded by approximately 30 gene copies. All of the U1 genes share several kilobases of essentially perfect flanking homology both upstream and downstream from the U1 coding region, but remarkably, for many U1 genes excellent flanking homology extends at least 24 kilobases upstream and 20 kilobases downstream. Class I U1 RNA pseudogenes are abundant in the human genome. These pseudogenes contain a complete but imperfect U1 coding region and possess extensive flanking homology to the true U1 genes. We mapped four class I pseudogenes by in situ hybridization to the long arm of chromosome 1, bands q12-q22, a region distinct from the site on the distal short arm of chromosome 1 to which the U1 genes have been previously mapped (Lund et al., Mol. Cell. Biol. 3:2211-2220, 1983; Naylor et al., Somat. Cell Mol. Genet. 10:307-313, 1984). We confirmed our in situ hybridization results by genomic blotting experiments with somatic cell hybrid lines with translocation products of human chromosome 1. These experiments provide further evidence that class I U1 pseudogenes and the true U1 genes are not interspersed. The results, along with those published elsewhere (Bernstein et al., Mol. Cell. Biol. 5:2159-2171, 1985), suggest that gene amplification may be responsible for the sequence homogeneity of the human U1 gene family.     

The outer mitochondrial membrane protein mitoNEET contains a novel redox-active 2Fe-2S cluster

The outer mitochondrial membrane protein mitoNEET was discovered as a binding target of pioglitazone, an insulin-sensitizing drug of the thiazolidinedione class used to treat type 2 diabetes (Colca, J. R., McDonald, W. G., Waldon, D. J., Leone, J. W., Lull, J. M., Bannow, C. A., Lund, E. T., and Mathews, W. R. (2004) Am. J. Physiol. 286, E252-E260). We have shown that mitoNEET is a member of a small family of proteins containing a 39-amino-acid CDGSH domain. Although the CDGSH domain is annotated as a zinc finger motif, mitoNEET was shown to contain iron (Wiley, S. E., Murphy, A. N., Ross, S. A., van der Geer, P., and Dixon, J. E. (2007) Proc. Natl. Acad. Sci. U. S. A. 104, 5318-5323). Optical and electron paramagnetic resonance spectroscopy showed that it contained a redox-active pH-labile Fe-S cluster. Mass spectrometry showed the loss of 2Fe and 2S upon cofactor extrusion. Spectroscopic studies of recombinant proteins showed that the 2Fe-2S cluster was coordinated by Cys-3 and His-1. The His ligand was shown to be involved in the observed pH lability of the cluster, indicating that loss of this ligand via protonation triggered release of the cluster. mitoNEET is the first identified 2Fe-2S-containing protein located in the outer mitochondrial membrane. Based on the biophysical data and domain fusion analysis, mitoNEET may function in Fe-S cluster shuttling and/or in redox reactions.     

Fluorescence microscopical demonstration of 5-hydroxydopamine in adrenergic nerves

Summary It is demonstrated that 5-hydroxydopamine (5HDA) is capable of forming highly fluorescent products with formaldehyde under conditions suitable for histochemical analyses. Prom absorptiometric and fluorometric studies it is reasonable to assume that the fluorophores formed are isoquinolines, in analogy with the reaction between, e.g., dopamine and formaldehyde. The reaction proceeds readily in protein layers and actual nerve terminals in tissues, allowing demonstration and identification of 5HDA in tissue structures. From studies on rat irides it is demonstrated that only adrenergic terminals take up 5HDA in demonstrable amounts.This work was supported by grants from the Swedish Medical Research Council (B69-14X-712-04C and B69-14X-2321-02), Knut och Alice Wallenbergs stiftelse and the Faculty of Medicine, University of Lund.     

Late Quaternary caviomorph rodents (Rodentia: Hystricognathi) from the Serra da Capivara,northeastern Brazil,with description of a new taxon

In this paper, fossil rodents (Hystricognathi: Caviomorpha) from the late Quaternary of the southwestern State of Piauí, northeastern Brazil, are described. The material comes from archaeological/palaeontological sites located in the region of the Serra da Capivara. The late Quaternary taxa of this region include Galea Meyen, 1832, Kerodon rupestris Wied-Neuwied, 1820, Hydrochoeridae indet., Dasyprocta Illiger, 1811, cf. Myocastor Kerr, 1792, Thrichomys Trouessart, 1880, Phyllomys Lund, 1839, Coendou magnus Lund, 1839 and a new taxon with chinchilloid affinities. The Coendou magnus and cf. Myocastor material represents the northernmost records of these taxa. The unexpected presence of a new extinct taxon contributes to the understanding of the ancient rodent faunas from South America. Today, the studied area is located within the Caatinga Biome but some of the fossil taxa, such as Hydrochoeridae and cf. Myocastor, indicate wetter environments and permanent water bodies during the late Pleistocene–early Holocene.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:92711BC3-8997-4474-A8AF-83DF4F91BB48     

Bodytime: On the Interaction of Body, Identity, and Society

Bodytime: On the Interaction of Body, Identity, and Society. Susanne Lundin and Lynn Åkesson. eds. Lund, Sweden: Lund University Press, 1996. 196 pp.     

Possible axo-axonal synapses between peripheral adrenergic and cholinergic nerve terminals

Summary The relations between adrenergic and cholinergic terminals were studied in rat iris and rat heart with the electron microscope. Adrenergic terminals were identified by treating the animals with 5-hydroxydopamine, which produces dense-cored synaptic vesicles in adrenergic terminals in tissues fixed in glutaraldehyde and osmium. The specificity of this observation was verified. It was found that adrenergic and cholinergic nerve terminals often come in close contact with one another, the distance between the adjoining membranes being about 250 Å. At times, faint membrane thickenings could be observed in these places. The available pharmacological, physiological, and morphological evidence leaves little room for doubt that cholinergic terminal fibres can influence the adrenergic fibres. From mainly morphological evidence, it is also postulated that adrenergic terminals influence cholinergic ones.This work was supported by grants from the United States Public Health Service (06701-04), the Faculty of Medicine, University of Lund, Lund, Sweden and the Swedish Medical Research Council (B70-14X-2321-03 and B70-14X-712-05). Svenska sällskapet för medicinsk forskning.     

Electron microscopic investigation of adrenergic and non-adrenergic axons in the rabbit SA-node

Summary The rabbit SA-node was outlined electrophysiologically and its adrenergic and cholinergic innervation patterns were studied with the electron microscope. Differentiation between adrenergic and cholinergic terminals was achieved by fixation of the specimens in KMnO₄ which produces dense-cored synaptic vesicles in adrenergic terminals, whereas synaptic vesicles in cholinergic terminals are empty. It was found that adrenergic and cholinergic nerve terminals often come in close apposition to each other, the distance between adjoining membranes being in the order of 250 Å. At times, faint membrane thickenings could be seen in these places. The available pharmacological, physiological and morphological evidence leaves little room for doubt that cholinergic terminal fibers can influence the adrenergic ones. From mainly morphological evidence it is also postulated that adrenergic terminals influence cholinergic terminals.This work was supported by grants from Åhlén-Stiftelsen, the Faculty of Medicine, University of Lund, Lund, Sweden, the United States Public Health Service (project 06701-04) and the Swedish Medical Research Council (B70-14X-2321-03 and B70-14X-712-05).     

Desmids of Iraq

Forty species and varieties of desmids belonging to the genera Closterium (7), Pleurotaenium (1), Euastrum (3), Cosmarium (28) and Staurastrum (1) have been described from southern Iraq including two new varieties under Cosmarium (i.e. C. cyclicum Lund, var. mesopotamianum var. nov., and C. tyrolicum (Nordst.) Krieger & Gerloff var. minor var. nov.). Most of the taxa are new records for Iraq.     

Ancient DNA preserved in small bone fragments from the P.W. Lund collection

The Lund collection is one of the oldest subfossil collections in the world. The vast assemblage of subfossils was collected in the 1830s and 1840s by Peter Wilhelm Lund in Lagoa Santa, Brazil, and was shipped to Copenhagen in 1848, where it was stored in various locations around the city with little attention for the future preservation of the collection. So far, successful genetic research on the material collected by Lund has been limited to two samples of human petrous bone. However, less is known about the preservation conditions of the vast amounts of small and fragmentary bones stored in the collection. To address this, we studied ancient DNA from bulk bone samples of approximately 100 bone fragments from the P.W. Lund collection from boxes with varying degrees of physical preservation conditions. Using bulk bone metabarcoding, we found a high species diversity in all samples. In total, we identified 17 species, representing 11 mammals, two birds, one fish, and three frogs. Of these, two species are new to the collection. Collectively, these results exhibit the potential of future genetic studies on the famous P.W. Lund collection and suggest that the effects of poor storage conditions are probably negligible compared with the long‐term in situ degradation that specimens undergo before excavation.     

Role of nuclear pools of aminoacyl-tRNA synthetases in tRNA nuclear export

Reports of nuclear tRNA aminoacylation and its role in tRNA nuclear export (Lund and Dahlberg, 1998; Sarkar et al., 1999; Grosshans et al., 20001) have led to the prediction that there should be nuclear pools of aminoacyl-tRNA synthetases. We report that in budding yeast there are nuclear pools of tyrosyl-tRNA synthetase, Tys1p. By sequence alignments we predicted a Tys1p nuclear localization sequence and showed it to be sufficient for nuclear location of a passenger protein. Mutations of this nuclear localization sequence in endogenous Tys1p reduce nuclear Tys1p pools, indicating that the motif is also important for nucleus location. The mutations do not significantly affect catalytic activity, but they do cause defects in export of tRNAs to the cytosol. Despite export defects, the cells are viable, indicating that nuclear tRNA aminoacylation is not required for all tRNA nuclear export paths. Because the tRNA nuclear exportin, Los1p, is also unessential, we tested whether tRNA aminoacylation and Los1p operate in alternative tRNA nuclear export paths. No genetic interactions between aminoacyl-tRNA synthetases and Los1p were detected, indicating that tRNA nuclear aminoacylation and Los1p operate in the same export pathway or there are more than two pathways for tRNA nuclear export.     

Estimation of breast burn size

It is the authors' opinion that the size of chest burns on large-breasted women can be significantly underestimated, especially if the methods of calculation rely on burn charts, such as the Lund and Browder burns chart. This latter chart is based on data derived from only three women and eight men. The surface area of the torsos of 60 volunteers (20 men, 20 small-breasted women, and 20 large-breasted women) was measured using two well-established techniques. The torso surface area was divided into two parts: the anterior trunk and the posterior trunk (i.e., torso surface area = posterior trunk + anterior trunk). The anterior trunk was subdivided and the area above the costal margins defined as the pectoral region. These areas were measured separately for each individual. The volunteers' total body surface area was calculated using normograms, based on their weight and height. The area of each torso section was recorded as a percentage of the total body surface area and torso surface area. Whereas the torso surface area/total body surface area ratio did not vary significantly between the groups, the proportion of anterior to posterior trunk size did depend on the sex and on breast size. There was a direct correlation between the woman's bra cup size and the ratio of anterior-to-posterior trunk surface area. A simple chart was therefore derived that estimates the relative size of a woman's torso surface area once her bra cup size is known. Such a chart can be used to improve accuracy in adult female chest burn estimation, when used in conjunction with a burns chart. Breast burns in larger breasted women are underestimated when calculated using current burn charts. We recommend that a correction be made when estimating chest burns in women to account for the increased surface area of the breasts. A chart, such as the one we have developed, could be used in conjunction with a burn chart (e.g., Lund and Browder) to make this correction.     

Production of amyloglucosidase by Aspergillus niger under different cultivation regimens

Amyloglucosidase (AMG) was produced by Aspergillus niger in solid-state fermentation (SSF), submerged fermentation (SmF) and an aqueous, two-phase system of polyethyleneglycol (PEG) and salt. In SSF, a fed-batch mode of operation gave a yield of 64 U/ml compared with 44 U/ml in batch mode. Similar trends were observed for SmF, where fed-batch cultivation gave a yield of 102 U/ml compared with 66 U/ml in batch. Shorter cultivation times (66 h) were required for SmF than for SSF (96 h). In the aqueous, two-phase cultivation, the productivity and yield of AMG were both twice those in the control fermentation.M. Ramadas is with the Department of Biochemistry, Faculty of Medicine, University of Jaffna, Kokuvil, Sri Lanka. O. Holst and B. Mattiasson are with the Department of Biotechnology, Chemical Center, Lund University, Box 124, S-221 00 Lund, Sweden     

Hybridization between the peat mosses, Sphagnum capillifolium and S. quinquefarium (Sphagnaceae, Bryophyta) as inferred by morphological characters and isozyme markers

 Isozyme markers and morphological characters were studied in four populations of Sphagnum capillifolium and S. quinquefarium. Recombinant plants were found in three populations, where the two species occur sympatrically. All recombinants possessed different haplotypes and combinations of morphological characters, which show that they are results of independent hybridization events. Strongly male-biased sex ratios were found for Sphagnum capillifolium in all populations where it grew sympatrically with S. quinquefarium. Most of the recombinants were also male fertile. These observations suggest that S. quinquefarium is the female parent in the primary crosses and in subsequent backcrosses. Received September 3, 2001; accepted March 16, 2002 Published online: November 7, 2002 Addresses of the authors: Nils Cronberg (e-mail: Nils.Cronberg@sysbot.lu.se), Department of Systematic Botany, Lund University, S?lvegatan 37, SE-223 62 Lund, Sweden. Rayna Natcheva (e-mail: renimoss@iph.bio.bas.bg), Institute of Botany, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria.     

Influence of anions on the activation of carbamoyl phosphate synthetase (ammonia) by acetylglutamate: implications for the activation of the enzyme in the mitochondria

Rat liver carbamoyl phosphate synthetase is shown to be inhibited by anions competitively with acetylglutamate (the allosteric activator of the enzyme) with a potency decreasing in the order NO3- greater than SO4(2-) greater than Cl- approximately HCO3-. Inhibition by chloride accounts for most of the inhibition reported [Lund, P., and Wiggins, D. (1987) Biochem. J. 243, 273-276] in Tris buffer. Mes, acetate, and isethionate give little or no inhibition and phosphate inhibits noncompetitively. Plots of the KA value for acetylglutamate versus the concentration of chloride or nitrate are curved upward and binding assays demonstrate that the inhibitory anions displace acetylglutamate from the enzyme. Thus, the anions may compete with the carboxyls of acetylglutamate for positive charges at the binding site. Of the organic anions found in the mitochondrial matrix, alpha-ketoglutarate, malate, succinate, and citrate increase substantially the KA for acetylglutamate. Changes in the concentrations of ATP, HCO3-, NH4+, and Mg2+, and high concentrations of protein (60 mg/ml serum albumin) influence the KA value. Changes in the concentration of the enzyme have no effect. Under assay conditions approaching the ionic, buffer, and substrate concentrations expected to occur in the mitochondrial matrix, the KA value for acetylglutamate is 27 microM and the Vmax is decreased about 50%. These results indicate that physiological changes in the level of acetylglutamate significantly influence the degree of activation of carbamoyl phosphate synthetase in vivo.