Página 1 dos resultados de 2391 itens digitais encontrados em 0.011 segundos

Structure, processing and midgut secretion of putative peritrophic membrane ancillary protein (PMAP) from Tenebrio molitor larvae

FERREIRA, A. H.; CRISTOFOLETTI, P. T.; PIMENTA, D. C.; RIBEIRO, A. F.; TERRA, W. R.; FERREIRA, C.
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
37.414644%
A cDNA coding for a Tenebrio molitor midgut protein named peritrophic membrane ancillary protein (PMAP) was cloned and sequenced. The complete cDNA codes for a protein of 595 amino acids with six insect-allergen-related-repeats that may be grouped in A (predicted globular)- and B (predicted nonglobular)-types forming an ABABAB structure. The PMAP-cDNA was expressed in Pichia pastoris and the recombinant protein (64 kDa) was purified to homogeneity and used to raise antibodies in rabbits. The specific antibody detected PMAP peptides (22 kDa) in the anterior and middle midgut tissue, luminal contents, peritrophic membrane and feces. These peptides derive from PMAP, as supported by mass spectrometry, and resemble those formed by the in vitro action of trypsin on recombinant PMAP. Both in vitro and in vivo PMAP processing seem to occur by attack of trypsin to susceptible bonds in the coils predicted to link AB pairs, thus releasing the putative functional AB structures. The AB-domain structure of PMAP is found in homologous proteins from several insect orders, except lepidopterans that have the apparently derived protein known as nitrile-specifier protein. Immunocytolocalization shows that PMAP is secreted by exocytosis and becomes entrapped in the glycocalyx...

Screening de uma bibliotecade expressãode cDNA de cerebelo de rato usando-se como sonda o anticorpo anti-KM+ e expressão de drebinas em displasia cortical focal IIB (DCF IIB) associada com epilepsia de difícil controle medicamentoso; Screning of a lambda zapii rat cerebellum library using an affinity-purified anti-lectin KM+ antibody expression of drebins in focal cortical dysplasia type type IIB (FCD IIB) associated with drug-resistant epilepsy

Maia, Roberta de Assis
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 01/06/2007 Português
Relevância na Pesquisa
37.082922%
p83 é uma proteína com massa molecular aparente de 83 kDa, supostamente ainda não descrita, específica de sistema nervoso, e desenvolvimento regulada. p83 interage fortemente com laminina, Tau, tubulina e heat shock protein 90. p83 foi inicialmente detectada por imunohistoquímica e western blot usando-se um anticorpo anti-lectina KM+ purificado por afinidade. Sua purificação a partir de cérebro de rato está em progresso. Identificar o envolvimento de p83 em processos do Sistema Nervoso Central humano é um passo necessário em direção à compreensão de sua função biológica. Uma biblioteca de expressão de cDNA de cerebelo de rato (Lambda ZAP II, Stratagene) foi submetida ao screening, usando-se um anticorpo específico para isolar o cDNA de p83. O anticorpo anti-KM+ foi pré-adsorvido contra proteínas de E. coli XL1 Blue MRF, antes de ser usado no screening. As membranas foram reveladas por imunodetecção cromogênica (fosfatase alcalina e NBT/BCIP). A análise de todos os clones Lambda ZAP II foi feita por excisão in vivo do fagomídeo pBluescript, subclonagem em E. coli XL1 Blue MRF, purificação do DNA plasmidial e digestão com Eco RI. A seqüência correspondente ao clone isolado foi analisada usando-se ferramentas e bancos de dados do NCBI. A seqüência nucleotídica mostrou identidade com as isoformas A e E de drebrina. As isoformas A e E de drebrina foram detectadas em adulto e embrião...

SEQUENCE OF A CDNA-ENCODING BOTHROPSTOXIN-I, A MYOTOXIN FROM THE VENOM OF BOTHROPS-JARARACUSSU

Ward, R. J.; Monesi, N.; Arni, R. K.; Larson, R. E.; Pacolarson, M. L.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 305-306
Português
Relevância na Pesquisa
36.923442%
With the aim of further understanding the structure/function relationships in the membrane-damaging activity of the Lys(49) phospholipase A(2) (Lys(49)-PLA(2)) sub-family, we used PCR (polymerase chain reaction) on total venom gland cDNAs from Bothrops jararacussu with degenerate oligodeoxyribonucleotides encoding the N- and C-termini of myotoxin II, a Lys(49)-PLA(2) from Bothrops asper. A 350-bp cDNA coding for bothropstoxin I (BtxtxI) was amplified. Sequencing of the amplified fragment shows that BtxtxI has a Lys(49), and comparison with the known structure of myotoxin II showed that the amino acids involved in the formation of a novel dimeric structure in this protein were also conserved.

Expressão gênica diferencial em palmitos de cana-de-açúcar submetida a diferentes períodos de estresse hídrico

Jovino, Daniele Fernanda Revoredo
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: xiii, 81 f. : il.
Português
Relevância na Pesquisa
36.967158%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV; Sob condições de estresse hídrico, a cana-de-açúcar pode sofrer mudanças fisiológicas e bioquímicas, tais como diminuição nas atividades fotoquímicas, redução da fixação de CO2 e acúmulo de osmólitos e osmoprotetores. O objetivo deste trabalho foi identificar, através da técnica de macroarranjo de cDNA, o perfil de expressão de genes promotores das diferentes vias metabólicas em palmitos da variedade de cana-de-açúcar SP80-3280 submetidas ao estresse hídrico nos dias 5, 9, 13 e 17 após o início da condição de supressão de água, sendo considerado o dia 1 como controle. Os resultados do macroarranjo mostraram que as proteínas mais expressas sob déficit hídrico pertencem a quatro categorias das quais as ESTs mais importantes foram selecionadas. As quatro categorias descritas abaixo estão discutidas neste trabalho. As ESTs da via do metabolismo de açúcar e amido (invertase de parede celular (INV), sacarose fosfato sintase (SFS), sacarose fosfato fosfatase (SFF), trealose fosfato sintase (TFS), trealose fosfato sintase/fosfatase (TFS/F) e hexoquinase (HXQ)) pertencem a categoria de bioenergética. Colina monooxigenase (CMO) e betaína aldeído desidrogenase (BADH) as quais pertencem a via do metabolismo de glicina betaína...

Characterization of mammalian translocase of inner mitochondrial membrane (Tim44) isolated from diabetic newborn mouse kidney

Wada, Jun; Kanwar, Yashpal S.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 06/01/1998 Português
Relevância na Pesquisa
27.530405%
Mammalian translocase of mitochondrial inner membrane (mTim44) was isolated during representational difference analysis of cDNA from diabetic mouse kidney. Streptozotocin-induced diabetic mouse kidney cDNA was prepared and subtracted by normal mouse kidney cDNA. By using one of the isolated cDNA fragments as a screening probe, full-length cDNA of mTim44 was isolated from λZAP kidney cDNA library. At the nucleotide level, mTim44 did not exhibit significant homology with any known genes; however, at the amino acid level, it had 50% similarity and 29% identity with yeast Tim44. C-terminal FLAG epitope-tagged mTim44 fusion protein was transiently expressed in COS7 cells. By using anti-FLAG epitope M2 monoclonal antibody, mTim44 was found to have its subcellular localization associated with mitochondria. By immunoelectron microscopy, mTim44 was seen in the paracrystalline structures within the mitochondria, as well as in their cristae. Mitochondrial import assay of in vitro translated mTim44 indicated that its precursor product (≈50 kDa) was imported and proteolytically processed to a mature ≈44-kDa protein, and its translocation was inner membrane potential (ΔΨ)-dependent. Imported mTim44 was protected from protease digestion in which outer membranes were selectively permeabilized with digitonin. The mature form of mTim44 could be recovered in the supernatant of sonicated mitochondrial membrane fraction treated with 0.1 M Na2CO3...

Prostate-specific membrane antigen is a hydrolase with substrate and pharmacologic characteristics of a neuropeptidase.

Carter, R E; Feldman, A R; Coyle, J T
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 23/01/1996 Português
Relevância na Pesquisa
27.413208%
This report demonstrates that the investigational prostatic carcinoma marker known as the prostate-specific membrane antigen (PSM) possesses hydrolytic activity with the substrate and pharmacologic properties of the N-acetylated alpha-linked acidic dipeptidase (NAALADase). NAALADase is a membrane hydrolase that has been characterized in the mammalian nervous system on the basis of its catabolism of the neuropeptide N-acetylaspartylglutamate (NAAG) to yield glutamate and N-acetylaspartate and that has been hypothesized to influence glutamatergic signaling processes. The immunoscreening of a rat brain cDNA expression library with anti-NAALADase antisera identified a 1428-base partial cDNA that shares 86% sequence identity with 1428 bases of the human PSM cDNA [Israeli, R. S., Powell, C. T., Fair, W. R. & Heston, W.D.W. (1993) Cancer Res. 53, 227-230]. A cDNA containing the entire PSM open reading frame was subsequently isolated by reverse transcription-PCR from the PSM-positive prostate carcinoma cell line LNCaP. Transient transfection of this cDNA into two NAALADase-negative cell lines conferred NAAG-hydrolyzing activity that was inhibited by the NAALADase inhibitors quisqualic acid and beta-NAAG. Thus we demonstrate a PSM-encoded function and identify a NAALADase-encoding cDNA. Northern analyses identify at least six transcripts that are variably expressed in NAALADase-positive but not in NAALADase-negative rat tissues and human cell lines; therefore...

Human catechol-O-methyltransferase: cloning and expression of the membrane-associated form.

Bertocci, B; Miggiano, V; Da Prada, M; Dembic, Z; Lahm, H W; Malherbe, P
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/02/1991 Português
Relevância na Pesquisa
27.449915%
A cDNA clone for human catechol-O-methyltransferase (hCOMT; S-adenosyl-L-methionine:catechol O-methyltransferase; EC 2.1.1.6) was isolated from a human hepatoma cell line (Hep G2) cDNA library by hybridization screening with a porcine cDNA probe. The cDNA clone was sequenced and found to have an insert of 1226 nucleotides. The deduced primary structure of hCOMT is composed of 271 amino acid residues with the predicted molecular mass of 30 kDa. At its N terminus it has a hydrophobic segment of 21 amino acid residues that may be responsible for insertion of hCOMT into the endoplasmic reticulum membrane. The primary structure of hCOMT exhibits high homology to the porcine partial cDNA sequence (93%). The deduced amino acid sequence contains two tryptic peptide sequences (T-22, T-33) found in porcine liver catechol-O-methyltransferase (COMT). The coding region of hCOMT cDNA was placed under the control of the cytomegalovirus promoter to transfect human kidney 293 cells. The endogenous COMT activity, which was approximately 9.98 units per mg of protein in the untransfected cells, increased to 206 units per mg of protein upon transfection with a plasmid containing the COMT cDNA. The COMT activity of recombinant protein was inhibited competitively (IC50 = 700 nM) by the selective COMT inhibitor Ro 40-7592. An anti-COMT monoclonal antibody recognized...

A single gene encodes membrane-bound and free forms of GP-2, the major glycoprotein in pancreatic secretory (zymogen) granule membranes.

Fukuoka, S; Freedman, S D; Scheele, G A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/04/1991 Português
Relevância na Pesquisa
27.367312%
GP-2, a 75-kDa glycoprotein, was isolated from dog pancreatic zymogen granule membranes (ZGMs). In a carbohydrate-shift strategy, N-terminal and internal peptide sequences were obtained on glycosylated and deglycosylated forms of GP-2, respectively, by gas-phase sequencing. Sets of mixed oligonucleotides and the polymerase chain reaction were used to obtain a double-stranded cDNA probe, which was used to isolate overlapping cDNA clones from a dog pancreatic cDNA library. The sequence of these clones revealed an open reading frame that encodes a protein of 509 amino acids, eight N-linked oligosaccharide attachment sites, and an N-terminal signal sequence absent from the mature form of GP-2 associated with ZGMs. The C terminus shows a 20-residue hydrophobic transmembrane domain preceded by a decapeptide containing potential phosphatidylinositol-glycan attachment sites. GP-2 completely released from ZGMs by exogenous phospholipase C showed similar immunochemical properties and electrophoretic mobilities compared to the form associated with ZGMs. A similar form of GP-2 was released from zymogen granules permeabilized with saponin and incubated in the absence of added phospholipase C. Kinetic analysis of GP-2 release at 0 degrees C and 37 degrees C suggested the presence of a granule enzyme responsible for endogenous release of GP-2 to granule contents and into the apical medium. The data indicate that GP-2 is a phosphatidylinositol-glycan-linked membrane protein released from the membrane of mature zymogen granules by an enzymatic mechanism. The cDNA structure presented here thus encodes both membrane-bound and free forms of GP-2.

Preparing a human membrane and secreted protein-enriched cDNA library using PCR primers derived from a genomic database

Fan, Yi; Wu, Chih Yuan; Chen, Cheng Wei; Chang, Tse Wen; Lim, Carmay
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 15/11/2001 Português
Relevância na Pesquisa
27.449915%
We describe here a strategy for preparing a human membrane and secreted protein (MSP)-enriched cDNA library based on human MSP- and non-MSP-encoding cDNA sequences in the databases. The signal peptide parts of the MSP-encoding cDNA sequences, which currently comprise about half of the estimated total number in humans, were analyzed for common patterns. These patterns form a ‘minimal’ set of polymerase chain reaction primer candidates of length varying from 9 to 21 nt. The products stemming from each primer candidate were determined and the results allowed us to obtain an ‘optimal’ mixed-length primer set. Ninety-six percent of the primers in this set were predicted to yield ≤10% undesired products, and the desired MSP-cDNA products could be easily separated by gel electrophoresis. The present analysis establishes a methodology for preparing a cDNA library that enables the analysis of individual MSPs. This methodology may also help identify new MSPs. As many cell regulatory processes are mediated by secreted proteins and their membrane-bound receptors, the preparation of a MSP-enriched cDNA library should benefit research on MSPs.

In vitro mutagenesis of a full-length cDNA clone of Semliki Forest virus: the small 6,000-molecular-weight membrane protein modulates virus release.

Liljeström, P; Lusa, S; Huylebroeck, D; Garoff, H
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1991 Português
Relevância na Pesquisa
27.367312%
We report on the construction of a full-length cDNA clone of Semliki Forest virus (SFV). By placing the cDNA under the SP6 promoter, infectious RNA can be produced in vitro and used to transfect cells to initiate virus infection. To achieve efficient transfections, a new protocol for electroporation of RNA was developed. This method gave up to 500-fold improvement over the traditional DEAE-dextran transfection procedure. Since virtually 100% of the cells can be transfected by electroporation, this method is a useful tool for detailed biochemical studies of null mutations of SFV that abolish production of infections virus particles. We used the cDNA clone of SFV to study what effects a deletion of the 6,000-molecular-weight membrane protein (6K membrane protein) had on virus replication. The small 6K protein is part of the structural precursor molecule (C-p62-6K-E1) of the virus. Our results conclusively show that the 6K protein is not needed for the heterodimerization of the p62 and E1 spike membrane proteins in the endoplasmic reticulum, nor is it needed for their transport out to the cell surface. The absence of the 6K protein did, however, result in a dramatic reduction in virus release, suggesting that the protein exerts its function late in the assembly pathway...

Expression of membrane interleukin 1 by fibroblasts transfected with murine pro-interleukin 1 alpha cDNA.

Fuhlbrigge, R C; Fine, S M; Unanue, E R; Chaplin, D D
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1988 Português
Relevância na Pesquisa
27.367312%
Studies of interleukin 1 (IL-1) alpha and beta have emphasized their functional similarities. IL-1 alpha and -beta are encoded by ancestrally related genes that have diverged dramatically in primary sequence; however, only modest differences in the regulation or biological activity of IL-1 alpha and IL-1 beta have been documented. Here we show that mouse L cells transfected with murine pro-IL-1 alpha cDNA expressed biologically active, 33-kilodalton pro-IL-1 alpha, and that this pro molecule was neither processed to the 17-kilodalton mature form nor secreted. The transfected cells also expressed membrane-associated IL-1 biological activity, indicating that the pro-IL-1 alpha cDNA can direct expression of membrane-associated IL-1 and that cleavage of the pro molecule is not required for membrane presentation. In contrast, transfection of pro-IL-1 beta cDNA did not generate biologically active material in L cells. Evidence is presented that the native murine IL-1 beta precursor molecule is also biologically inactive in peritoneal exudate cells stimulated with lipopolysaccharide. These differences in distribution of the bioactive forms of IL-1 alpha and IL-1 beta may provide selective advantages for the maintenance of two gene products with similar functions.

Isolation and characterization of cDNA clones for rat ribophorin I: complete coding sequence and in vitro synthesis and insertion of the encoded product into endoplasmic reticulum membranes

Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/04/1987 Português
Relevância na Pesquisa
27.47864%
Ribophorins I and II are two transmembrane glycoproteins that are characteristic of the rough endoplasmic reticulum and are thought to be part of the apparatus that affects the co-translational translocation of polypeptides synthesized on membrane-bound polysomes. A ribophorin I cDNA clone containing a 0.6-kb insert was isolated from a rat liver lambda gtll cDNA library by immunoscreening with specific antibodies. This cDNA was used to isolate a clone (2.3 kb) from a rat brain lambda gtll cDNA library that contains the entire ribophorin I coding sequence. SP6 RNA transcripts of the insert in this clone directed the in vitro synthesis of a polypeptide of the expected size that was immunoprecipitated with anti-ribophorin I antibodies. When synthesized in the presence of microsomes, this polypeptide, like the translation product of the natural ribophorin I mRNA, underwent membrane insertion, signal cleavage, and co-translational glycosylation. The complete amino acid sequence of the polypeptide encoded in the cDNA insert was derived from the nucleotide sequence and found to contain a segment that corresponds to a partial amino terminal sequence of ribophorin I that was obtained by Edman degradation. This confirmed the identity of the cDNA clone and established that ribophorin I contains 583 amino acids and is synthesized with a cleavable amino terminal insertion signal of 22 residues. Analysis of the amino acid sequence of ribophorin I suggested that the polypeptide has a simple transmembrane disposition with a rather hydrophilic carboxy terminal segment of 150 amino acids exposed on the cytoplasmic face of the membrane...

Secretory Carrier Membrane Protein 2 Regulates Exocytic Insertion of NKCC2 into the Cell Membrane*

Zaarour, Nancy; Defontaine, Nadia; Demaretz, Sylvie; Azroyan, Anie; Cheval, Lydie; Laghmani, Kamel
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.90638%
The renal-specific Na-K-2Cl co-transporter, NKCC2, plays a pivotal role in regulating body salt levels and blood pressure. NKCC2 mutations lead to type I Bartter syndrome, a life-threatening kidney disease. Regulation of NKCC2 trafficking behavior serves as a major mechanism in controlling NKCC2 activity across the plasma membrane. However, the identities of the protein partners involved in cell surface targeting of NKCC2 are largely unknown. To gain insight into these processes, we used a yeast two-hybrid system to screen a kidney cDNA library for proteins that interact with the NKCC2 C terminus. One binding partner we identified was SCAMP2 (secretory carrier membrane protein 2). Microscopic confocal imaging and co-immunoprecipitation assays confirmed NKCC2-SCAMP2 interaction in renal cells. SCAMP2 associated also with the structurally related co-transporter NCC, suggesting that the interaction with SCAMP2 is a common feature of sodium-dependent chloride co-transporters. Heterologous expression of SCAMP2 specifically decreased cell surface abundance as well as transport activity of NKCC2 across the plasma membrane. Co-immunolocalization experiments revealed that intracellularly retained NKCC2 co-localizes with SCAMP2 in recycling endosomes. The rate of NKCC2 endocytic retrieval...

Phytophthora nicotianae PnPMA1 encodes an atypical plasma membrane H+-ATPase that is functional in yeast and developmentally regulated

Shan, Weixing; Liu, Jun; Hardham, Adrienne R
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica Formato: 10 pages
Português
Relevância na Pesquisa
36.880532%
PnPMA1, a gene encoding a putative P-type plasma membrane H+-ATPase, has been isolated by differential screening of a Phytophthora nicotianae germinated cyst cDNA library. PnPMA1 is differentially expressed during pathogen asexual development with a more than 10-fold increase in expression in germinated cysts, the stage at which plant infection is initiated, compared to vegetative or sporulating hyphae or motile zoospores. PnPMA1 proteins are encoded by two closely linked genes that have no introns and encode identical proteins having 1068 amino acid residues and a molecular mass of 116.3 kDa. PnPMA1 shows moderate identity (30–50%) to plant and fungal plasma membrane H+-ATPases and weak identity to other P-type cation-transporting ATPases. PnPMA1 contains all the catalytic domains characteristic of H+-ATPases but also has a distinct domain of ~155 amino acids that forms a putative cytoplasmic loop between transmembrane domains 8 and 9, a feature that is not present in PMA1 proteins from other organisms. Polyclonal antibodies raised against the 155 residue domain were shown by immunogold labelling to react with a protein in the plasma membrane of P. nicotianae germinated cysts but not with the plasma membrane of motile zoospores. Genetic complementation experiments demonstrated that the P. nicotianae PnPMA1 is functional in yeast...

Cloning of the human uroplakin 1B cDNA and analysis of its expression in urothelial-tumor cell lines and bladder-carcinoma tissue

Finch, J.; Miller, J.; Aspinall, J.; Cowled, P.
Fonte: WILEY-LISS Publicador: WILEY-LISS
Tipo: Artigo de Revista Científica
Publicado em //1999 Português
Relevância na Pesquisa
36.923442%
The human uroplakin 1B (UPK1B) gene codes for a structural protein which is a terminal differentiation component of the asymmetric unit membrane on the apical surface of the mammalian bladder. UPK1B is a member of the tetraspan family of proteins, many of which have de-regulated patterns of expression in cancer. Using polymerase-chain-reaction techniques, we have cloned a partial human UPK1B cDNA which codes for the putative full open reading frame for the UPK1B protein. The deduced human UPK1B protein sequence has 92% and 93% amino-acid homology with bovine UPK1b and mink TI1 proteins respectively. Using Northern analysis, we show that the human UPK1B gene is highly expressed in normal human urothelium. However, expression of UPK1B mRNA was undetectable or markedly reduced in 11 out of 16 samples of transitional-cell-bladder-carcinoma tissue and in all 5 bladder-carcinoma cell lines when compared with normal urothelial tissue. The molecular mechanism of down-regulation of RNA expression does not appear to involve gross gene rearrangements or allelic loss.; Jennie L. Finch, John Miller, James O. Aspinall, Prudence A. Cowled

Isolation and characterisation of a cDNA encoding a Zona Pellucida Protein (ZPB) from the marsupial Trichosurus vulpecula (Brushtail Possum)

Haines, B.; Rathjen, P.; Hope, R.; Whyatt, L.; Holland, M.; Breed, W.
Fonte: WILEY-LISS Publicador: WILEY-LISS
Tipo: Artigo de Revista Científica
Publicado em //1999 Português
Relevância na Pesquisa
37.036978%
We have cloned a cDNA containing the entire coding sequence of a marsupial (the brushtail possum, Trichosurus vulpecula) zona pellucida protein (ZPB). The open reading frame of 1,581 nt is predicted to encode a ZPB polypeptide of 527 amino acids which contains 20 cysteine residues, 7 potential N-linked glycosylation sites, a potential N-terminal signal peptide and a potential C-terminal trans-membrane domain, preceded by a furin proteolytic processing signal. Sequence comparisons between possum ZPB and orthologous polypeptides from 7 eutherian species and from Xenopus laevis, reveal the existence of a high degree of sequence similarity, particularly in the central portion of the molecule. Cysteine residues are highly conserved, and all nine species possess potential N-terminal signal peptide sequences and C-terminal trans-membrane domains of approximately the same length. In situ hybridisation revealed that expression of ZPB was restricted to oocytes of primordial and primary follicles of adult possums; no expression was detected in the surrounding granulosa cells. The broad conservation of ZPB sequence, structure and expression over a wide range of mammalian species, revealed by our studies, makes it unlikely that these features account for the different properties of the marsupial and eutherian zona pellucidae.; Article first published online: 4 JAN 1999

Skin peptide and cDNA profiling of Australian anurans: Genus and species identification and evolutionary trends

Jackway, R.; Pukala, T.; Donnellan, S.; Sherman, P.; Tyler, M.; Bowie, J.
Fonte: Elsevier Science Inc Publicador: Elsevier Science Inc
Tipo: Artigo de Revista Científica
Publicado em //2011 Português
Relevância na Pesquisa
36.706692%
Host defense peptides of 35 species of Australian frogs from the hylids Cyclorana and Litoria, and the myobatrachids Crinia, Limnodynastes and Uperoleia have been identified. The biological activities of the majority of these peptides have been determined and include hormones, neuropeptides, opioids, immunomodulators, membrane active peptides [including antimicrobial, anticancer, antiviral (enveloped viruses like HIV and Herpes) and antifungal peptides], neuronal nitric oxide synthase inhibitors, pheromones and individual peptides with other specific activities. The host defense peptide skin profile can be diagnostic at both the species and higher taxonomic levels; for example, species of Crinia, Litoria and Uperoleia each produce quite different types of peptides. Species of Cyclorana and Limnodynastes are more difficult to characterize by skin peptides alone: species of both genera produce similar peptides with no apparent activity. The skin peptide profiles of frogs from the genera Crinia, Litoria and Uperoleia may be used together with morphological and cognate methods, to differentiate between sub-species and even different population clusters of the same species. Nucleotide sequencing of cDNAs of precursors (pre-pro peptides) of bioactive peptides from the skin glands of various species of the genus Litoria show that the majority of these peptides originated from a single ancestor gene before the break away of Australia from Gondwana. The exceptions are the caerulein neuropeptides {e.g. caerulein [pEQDY(SO(3)H)TGWMDF(NH(2))]} which have a different origin to that of other Litoria peptides. Disulfide containing peptides from skin glands of species of Crinia show a different evolutionary route to peptides from species of Litoria.; http://www.elsevier.com/wps/find/journaldescription.cws_home/525495/description#description; Rebecca J. Jackway...

Isolation of the cDNA for erythrocyte integral membrane protein of 28 kilodaltons: member of an ancient channel family.

Preston, G M; Agre, P
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/12/1991 Português
Relevância na Pesquisa
27.434531%
CHIP28 is a 28-kDa integral membrane protein with similarities to membrane channels and is found in erythrocytes and renal tubules. A cDNA for CHIP28 was isolated from human fetal liver cDNA template by a three-step polymerase chain reaction (PCR) cloning strategy, starting with degenerate oligonucleotide primers corresponding to the N-terminal amino acid sequence determined from purified CHIP28 protein. Using the third-step PCR product as a probe, we isolated a recombinant from a human bone marrow cDNA library. The combined sequence of the PCR products and bone marrow cDNA contains 38 base pairs of 5' untranslated nucleotide sequence, an 807-bp open reading frame, and approximately 2 kilobases of 3' untranslated sequence containing a polyadenylation signal. This corresponds to the 3.1-kilobase transcript identified by RNA blot-hybridization analysis. Authenticity of the deduced amino acid sequence of the CHIP28 protein C terminus was confirmed by expression and immunoblotting. Analysis of the deduced amino acid sequence suggests that CHIP28 protein contains six bilayer-spanning domains, two exofacial potential N-glycosylation sites, and intracellular N and C termini. Search of the DNA sequence data base revealed a strong homology with the major intrinsic protein of bovine lens...

A C-terminal, calmodulin-like regulatory domain from the plasma membrane Ca2+-pumping ATPase.

Brandt, P; Zurini, M; Neve, R L; Rhoads, R E; Vanaman, T C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1988 Português
Relevância na Pesquisa
27.483076%
A cDNA that encodes what appears to be the inhibitory domain of the plasma membrane calcium-pumping ATPase (Ca2+-ATPase) has been isolated by screening a lambda gt11 bovine brain cDNA library with antibodies prepared against the human erythrocyte membrane Ca2+-ATPase. This screening resulted in isolation of a bacteriophage containing a 1.5-kilobase cDNA insert encoding a 71-residue polypeptide, the remainder being a large 3' terminal noncoding region. A portion of this deduced peptide sequence was identical to that of a peptide isolated from a V8 protease digest of the human erythrocyte Ca2+-ATPase except for 1 residue. Antibodies purified by immunoabsorption to the fusion protein containing this cDNA-encoded polypeptide reacted only with those fragments of a limited trypsin digest of the human erythrocyte Ca2+-ATPase that contain the inhibitory domain. Moreover, these antibodies were able to partially stimulate basal enzyme activity and block further activation by calmodulin. The encoded polypeptide bears homology to the glutamic acid-rich regions N-terminal to the Ca2+-binding loops of calmodulin and to a lesser extent with the loops themselves. This encoded polypeptide also represents the C terminus of the Ca2+-ATPase. Portions of the isolated cDNA were homologous to the 3' noncoding region of the sarcoplasmic reticulum Ca2+-ATPase cDNA...

Human carboxypeptidase E. Isolation and characterization of the cDNA, sequence conservation, expression and processing in vitro.

Manser, E; Fernandez, D; Loo, L; Goh, P Y; Monfries, C; Hall, C; Lim, L
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/04/1990 Português
Relevância na Pesquisa
27.367312%
Carboxypeptidase E (CPE), which cleaves C-terminal amino acid residues and is involved in neuropeptide processing, is itself subject to intracellular processing. Human CPE cDNA was isolated and sequence comparisons were made with those of a previously isolated brain cDNA (M1622) encoding rat CPE and of other human carboxypeptidases (M and N). Human (2.5 kb) and rat (2.1 kb) CPE cDNAs approximated to the size of their respective mRNAs; additional sequences were located in putative 5' and 3' untranslated regions of human CPE mRNA. There is 79% sequence similarity between human and rat CPE cDNAs, with greater similarity (89%) over the coding region and short sections of the non-coding sequence. The predicted 476-amino acid-residue sequences of human and rat preproCPEs are highly conserved (96% identity), with lower degree of similarity of the N-terminal signal peptide (76%). Human CPE showed 51% and 43% sequence similarity to human CPN and CPM respectively, with discrete regions of divergence dispersed between the highly conserved mechanistically implicated regions. Antiserum generated from a fusion protein, synthesized in Escherichia coli from constructs of the human cDNA, recognized an approx. 50 kDa membrane protein and a smaller soluble protein in rat and human brain preparations...