Report on the Na+/H+ Exchanger Satellite Meeting at the 53rd Annual Meeting of the Canadian Society of Biochemistry, Molecular and Cellular Biology

The Satellite Meeting on Na+/H+ Exchangers, held on 17 April 2010, covered a range of new developments in this field. The symposium was chaired by Dr. Larry Fliegel, University of Alberta, and the speakers were Dr. John Orlowski of McGill University, Dr. Jan Rainey of Dalhousie University, Dr. Etana Padan of The Hebrew University of Jerusalem, Dr. Masa Numata of The University of British Columbia, Dr. Pavel Dibrov from the University of Manitoba, Dr. Todd Alexander of the University of Alberta, and Grant Kemp of the University of Alberta. Talks ranged from organellar pH homeostasis to structure and function of Na+/H+ exchanger proteins. Highlights of the symposium included elucidation of the structure of transmembrane regions of the NHE1 isoform and development of a new model of the NHE1 protein based on the E. coli Na+/H+ exchanger. The symposium brought together scientists from different corners of the world. The discussions that followed were lively and many scientists received constructive comments from their peers.     

Q & A

Gregory A. Petsko is Gyula and Katica Tauber Professor of Biochemistry and Chemistry and Director of the Rosenstiel Basic Medical Sciences Research Center at Brandeis University. He did his undergraduate work at Princeton and his graduate work as a Rhodes Scholar at Oxford University. He held faculty positions at Wayne State University School of Medicine and MIT before moving to Brandeis in 1990. A structural biologist, he is best known for his work, together with his colleague Dagmar Ringe, on the structural basis of enzyme catalytic power and the role of protein dynamics in protein function. He writes a regular opinion column for the journal Genome Biology.     

Protein enrichment of lignocellulose resulting from the growth of two Streptomyces strains

Two Streptomyces strains were grown on sugarcane bagasse and groundnut hulls lignocelluloses in semi-solid state culture at 37°C for 12 weeks. Best results gave a 45% depletion of sugarcane bagasse lignocellulose with a 21% crude protein content of final material. The possibility of using S. viridosporus to improve the protein content of both lignocelluloses for use as an animal feedstock supplement is discussed.At the time of this research the authors were with the Department of Biological Sciences, Rivers State University of Science & Technology, PMB 5080, Port Harcourt, Nigeria and the Department of Biological Sciences, University of Calabar, PMB 1115, Calabar, Nigeria. Dr lyo is now with the Department of Microbiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.     

DC-SIGN蛋白在家蚕系统中的表达及生物活性研究

目的：构建人DC-SIGN基因片段的家蚕表达系统,进行目的产物表达、鉴定及生物活性分析。方法：从体外刺激分化的DC细胞中克隆出DC-SIGN cDNA,在家蚕表达载体pBacPAK8的BamHⅠ和EcoRⅠ位点构建成重组质粒pBacPAK8-DC-SIGN,与线性化的Bm-BacPAK6病毒基因组DNA共转染家蚕细胞,空斑筛选得到重组病毒Bm-BacPAK-DC-SIGN,重组病毒感染家蚕细胞BmN,Western blot检测表达产物;HIV-1包膜糖蛋白gp120与表达产物孵育检测其生物活性。结果：构建了稳定表达人DC-SIGN蛋白片段的家蚕杆状病毒表达系统;成功表达了DC-SIGN蛋白片段,且能特异性地与HIV-1包膜糖蛋白gp120结合。结论：成功地在家蚕杆状病毒表达系统中表达了人DC-SIGN蛋白片段,具有天然DC-SIGN蛋白样的生物活性,为其抗体制备及AIDS防治药物的研发奠定了基础。     

Epigenomics: novel aspect of genomic regulation

An International Symposium on Epigenomics took place at Yonsei University, Korea in December, 2006. The meeting brought to light new aspects of genome regulation by DNA and protein modification.     

Immunogold localization of chymotrypsin inhibitor-2, a lysine-rich protein,in developing barley endosperm

Chymotrypsin inhibitor-2, a lysine-rich protein in the barley endosperm, has been localized at the ultrastructural level by immunocytochemistry in developing barley endosperm cells 14 days post anthesis. The protein is deposited in the protein bodies. Two morphologically distinct types of protein bodies, small spherical and large irregularly shaped, are present. Golgi-apparatus-derived vesicles whose content is labelled by chymotrypsin inhibitor-2 antibody-gold particles are observed at the Golgi complex and around the vacuoles. These observations indicate that the transport of the protein to the site of deposition is mediated by the Golgi apparatus.Abbreviations CI chymotrypsin inhibitor - DPA days post anthesis - ER endoplasmic reticulum The authors wish to thank Dr. V.R. Franceschi (Department of Botany, Washington State University, Pullman, USA) for many helpful discussions and advice during the work, and the staff at the Electron Microscope Center at Washington State University for technical assistance.     

Characterization of a low molecular weight antigenic protein from the envelope of influenza virus

Eckert, Edward A. (The University of Michigan, Ann Arbor). Characterization of a low molecular weight antigenic protein from the envelope of influenza virus. J. Bacteriol. 92:1430-1434. 1966.-An antigenic protein from the lipid-extracted residue of influenza virus strain PR8 was solubilized with urea-dithiothreitol (DTT). The protein subunits had a sedimentation coefficient of 2S in urea-DTT and reassociated to a 4S state on dialysis. This form of the envelope protein did not agglutinate erythrocytes, but reacted with strain-specific antisera in the complement-fixation and blocking-antigen tests.     

Fine structure of endosperm protein bodies inSetaria lutescens (Gramineae)

Summary Endosperm protein bodies are membrane bound. Internally, each body shows a pattern of dark and light concentric layers. A median dense core may also be present. These bodies stain for protein with mercuric bromphenol blue, but not for acid phosphatase.Based on a portion of a dissertation submitted to the Graduate College of Iowa State University in partial fulfillment of the requirements for the Ph. D. degree.     

Mechanisms of homocysteine toxicity in humans

Summary. Homocysteine, a non-protein amino acid, is an important risk factor for ischemic heart disease and stroke in humans. This review provides an overview of homocysteine influence on endothelium function as well as on protein metabolism with a special respect to posttranslational modification of protein with homocysteine thiolactone. Homocysteine is a pro-thrombotic factor, vasodilation impairing agent, pro-inflammatory factor and endoplasmatic reticulum-stress inducer. Incorporation of Hcy into protein via disulfide or amide linkages (S-homocysteinylation or N-homocysteinylation) affects protein structure and function. Protein N-homocysteinylation causes cellular toxicity and elicits autoimmune response, which may contribute to atherogenesis. Present address: Department of Biochemistry and Biotechnology, Agricultural University, 60637 Poznań, Poland     

Ezrin蛋白在甲状腺乳头状癌中的表达及其与生存期关系的研究

目的探讨膜细胞骨架链接蛋白Ezrin在甲状腺乳头状癌组织中的表达及其与生存期关系的研究。方法收集武汉大学人民医院和武汉大学中南医院病理2000-2006年手术切除及活检的甲状腺乳头状癌标本40例和甲状腺腺瘤标本20例。采用免疫组织化学方法检测各组组织内Ezrin蛋白的表达。利用HPIAS-2000图像分析系统测定Ezrin蛋白在甲状腺乳头状癌及甲状腺腺瘤中表达的平均光密度和平均阳性面积率,并结合临床资料进行总生存期分析。结果 1.甲状腺乳头状癌组织中Ezrin蛋白呈高表达;甲状腺腺瘤中Ezrin蛋白呈低表达;图像分析结果显示两组间差异有显著性意义(P<0.05)。2.Ezrin蛋白表达强阳性组总生存期均短于表达弱阳性组(P<0.05),差异有统计学意义。结论 Ezrin蛋白与甲状腺乳头状癌的发生、发展及临床预后有密切关系。     

Protein Kinase Inhibitors Inhibit Stimulation of Inositol Phospholipid Turnover and Induction of Phenylalanine Ammonia-Lyase in Fungal Elicitor-Treated Tobacco Suspension Culture Cells

Elicitor prepared from Phytophthora nicotianae stimulated inositolphospholipid turnover and induced phenylalanine ammonia-lyaseactivity in tobacco suspension culture cells [Kamada and Muto(1994) Plant Cell Physiol. 35: 397]. Protein kinase inhibitors,K252a and staurosporine inhibited both responses. These resultssuggest that inositol phospholipid turnover plays an importantrole in PAL induction through protein kinases. In addition,their mode of inhibition were different, proposing that severaltypes of protein kinases are involved in these elicitor-inducedresponses. ¹Present address: The Johns Hopkins University School of Hygieneand Public Health, 615 N. Wolfe St., Baltimore, Maryland 21205,U.S.A. ²Present address: Nagoya University BioScience Center and GraduateSchool of Agricultural Sciences, Nagoya University, Chikusa-ku,Nagoya, 464-01 Japan.     

Qualitative analysis by isoelectric focusing of the protein content of Pharbitis nil apices and cotyledons during floral induction

The protein content of apices and cotyledons in Morally inducedor vegetative plants of Pharbitis nilwas examined using isoelectricfocusing. No differences were found in the protein patternsproduced by apical tissue with and without floral induction.Cotyledons, however, repeatedly showed the distinct loss ofa single protein band on floral induction. ¹Current address: Department of Radiation Biology and Biophysics,The University of Rochester School of Medicine and Dentristry,Rochester, N.Y. 14642, U.S.A. (Received March 29, 1976; )     

Cell elongation in the soybean root: The influence of inhibitors of RNA and protein biosynthesis

A possible requirement for RNA and protein synthesis duringcell elongation of intact seedling tissue was studied usingthe soybean seedling foot with the elongating zone being delineatedby India ink marks at 2 and 7 mm back of the root tip. In contrastto most excised plant tissues, there was marked net synthesisof RNA and protein during cell elongation of the intact root.AD and CH were potent inhibitors of cell elongation in the soybeanroot. CH essentially eliminated protein synthesis, whether measuredby net accumulation of protein or by ¹⁴C-leiicine incorporation,while completely inhibiting cell elongation after a short lag.AD, on the other hand, only partially inhibited protein synthesiswhile causing almost total inhibition of cell elongation aftera lag. The capacity of the tissue to synthesize protein in thepresence of AD was correlated with the maintenance of functionalpolyribosomes, thus suggestive that m-RNA associated with theregulation of cell elongation is more unstable (i.e., a shortermean life) than total root m-RNA. FU did not inhibit cell elongation,protein synthesis or the level of functional polyribosomes.The requirement for RNA synthesis during cell elongation ofthe seedling root, as in excised plant tissues, appears to berestricted to the AMPrich species of RNA presumed to be m-RNA. ¹This research was supported by NIH grant GM 10157. ²Purdue University AES paper No. 3359. ³Present address: Dept. of Botany, National Taiwan University,Taipei, Taiwan.     

Philip Cohen

Philip Cohen trained at University College London and, after postdoctoral research at the University of Washington, joined the University of Dundee Scotland, in 1971, where he has worked ever since. He is a Royal Society Research Professor and Director of the Medical Research Council Protein Phosphorylation Unit. His main contributions have been in the area of protein phosphorylation and its role in cell regulation and human disease. In 1998, he was knighted for his contributions to biochemistry and the development of Life Sciences at Dundee.     

Immunocytochemical detection of 28000-MW calcium-binding protein in horizontal cells of the rat retina

Summary Horizontal cells of rat retina were labeled intensely by a specific antibody to cerebellar calcium-binding protein. The amacrine cells stained very weakly. The presence of calcium-binding protein in horizontal cells could be of interest for the understanding of the feedback action of these cells on photoreceptors.Abbreviations used CaBP calcium-binding protein - DAB 3,3-diaminobenzidine - PAP unlabelled antibody peroxidase-antiperoxidase immunocytochemical complex On leave from the Department of Physiology, University of British Columbia, Vancouver, Canada     

Protein enrichment of apple pomace by co-culture of cellulolytic moulds and yeasts

The co-culture of cellulolytic moulds and yeasts on apple pomace in solid-state fermentation (SSF) and liquid-state fermentation (LSF) increased the protein content of apple pomace. The co-culture of Candida utilis and Aspergillus niger was the best among several combinations and increased the protein content of dried and pectin-extracted apple pomace to 20% and 17%, respectively, under SSF conditions.The authors are with the Microbiology Research Laboratory, Department of Biosciences, Himachal Pradesh University, Shimia-171005, India.     

Arrest of cell division but not protein synthesis in sodium-deficient cells of the marine diatom Phaeodactylum tricornutum Bohlin

Cell division in the marine diatom Phaeodactylum tricornutum was prevented when cultures were maintained in the absence of sodium, regardless of the nitrogen status of the cells or medium. Addition of 10 mM ammonium and 50 mM sodium to cultures preconditioned in nitrogen and sodium-deficient medium for 5 d led to a recovery in cell division and chlorophyll a, and net protein synthesis. Sodium added in the absence of ammonium led to a recovery in cell division, but not net protein synthesis. Ammonium added in the absence of sodium was partially assimilated (as NH₃) and resulted in a small amount of protein synthesis, but without cell division. This effect was enhanced if the cells had lower protein quotas prior to ammonium addition, with total consumption of the added 1 mM ammonium and appreciable net protein synthesis. Respiration was enhanced by 1 or 10 mM ammonium or 10 mM methylammonium addition to nitrogen-deficient cultures maintained in the presence or absence of sodium. In contrast to respiration, photosynthesis was inhibited by these additions in sodium-replete cultures, but was enhanced in sodium-deficient cultures.This research was supported by the Auckland University Research Committee and University Grants Committee of New Zealand.     

Structural features of insoluble elastin

Summary There is a dychotomy of opinion regarding the molecular configuration of elastin. Some authors sustain that this protein is amorphous while others believe that it is fibrillar in structure. In this investigation attempts have been made to better understand the fine structural characteristics of elastin. Thus, to this end, purified elastin preparations from pig aorta and ox ligamentum nuchae were either embedded in Epon and the sections examined at the electron microscope or minced, ground and then collected on carbon-coated grids and analyzed. In other experiments whole mouse aortas from Swiss albino mice were fixed in glutaraldehyde, embedded and stained with uranyl acetate and lead hydroxide or with acidic PTA.The results indicated that when elastin is examined as an embedded specimen it shows no organized substructure. Conversely, when the same protein preparation is first dispersed and then examined on carbon-coated grids fine filamentous units make up the bulk of the structure.Work performed as part of a research project of the University of Alabama in Birmingham and the University of Rome initiated under the cooperative program in Science between the United States and the Republic of Italy.Supported in part by a Grant from the C.N.R., Rome, Italy.     

Solid-state fermentation of carob pods byAspergillus niger for protein production: effect of particle size

Two strains ofAspergillus niger were cultured in solid-state fermentation system on carob pods ground from 1.25 to 8 mm diam. A particle size of 2.5 mm gave the highest protein content of the final product (20%, w/w) and 52% of the total soluble carbohydrates were utilized. The total tannin concentration of the carob pods decreased by 83% in 4 days of fermentation.T. Smail and O. Salhi are with the Laboratory of Microbiology, U.R.B.A.F., Institute of Biology, Tizi-Ouzou University, Algeria. J.S. Knapp is with the Department of Microbiology, The University of Leeds, Leeds LS2 9JT, UK;     

Proteomics data mining

Marc Wilkins completed his undergraduate and doctoral studies at Macquarie University, Sydney, Australia. During his doctoral studies, he defined the concept of the proteome and coined the term. After postdoctoral studies in Geneva, Switzerland, during which he co-edited the first book on proteomics, he returned to Australia, where he cofounded the company Proteome Systems. More recently, Marc took a position as Professor of Systems Biology at the University of New South Wales. He has established and directs the NSW Systems Biology Initiative, and is currently researching the role that protein post-translational modifications play in the regulation of protein-interaction networks.