Search results for " Homology"
showing 10 items of 633 documents
Cloning of two melanocortin (MC) receptors in spiny dogfish
2004
We report the cloning and characterization of two melanocortin receptors (MCRs) from the spiny dogfish (Squalus acanthias) (Sac). Phylogenetic analysis shows that these shark receptors are orthologues of the MC3R and MC5R subtypes, sharing 65% and 70% overall amino acid identity with the human counterparts, respectively. The SacMC3R was expressed and pharmacologically characterized in HEK293 cells. The radioligand binding results show that this receptor has high affinity for adrenocorticotropic hormone (ACTH)-derived peptides while it has comparable affinity for alpha- and beta-melanocyte stimulating hormone (MSH), and slightly lower affinity for gamma-MSH when compared with the human ortho…
The estrogen receptor α:insulin receptor substrate 1 complex in breast cancer: structure–function relationships
2007
Background: Insulin receptor substrate 1 (IRS-1) is a signaling molecule that exerts a key role in mediating cross talk between estrogen receptor a (ERa) and insulin-like growth factor 1 (IGF-1) in breast cancer cells. Previously, we demonstrated that a fraction of IRS-1 binds ERa, translocates to the nucleus, and modulates ERa-dependent transcription at estrogen response elements (ERE). Here, we studied structure-function relationships of the ER-a:IRS-1 complex under IGF-1 and/or estradiol (E 2 ) stimulation. Materials and methods: ERa and IRS-1 deletion mutants were used to analyze structural and functional ERα/IRS-1 interactions. IRS-1 binding to ERE and IRS-1 role in ERa-dependent ERE t…
H2-M polymorphism in mice susceptible to collagen-induced arthritis involves the peptide binding groove.
1996
The ability to develop type II collagen (CII)-induced arthritis (CIA) in mice is associated with the major histocompatibilityI-A gene and with as yet poorly defined regulatory molecules of the major histocompatibility complex (MHC) class II antigen processing and presentation pathway. H2-M molecules are thought to be involved in the loading of antigenic peptides into the MHC class II binding cleft. We sequencedH2-Ma, H2-Mb1, andH2-Mb2 genes from CIA-susceptible and-resistant mouse strains and identified four differentMa andMb2 alleles and three differentMb1 alleles defined by polymorphic residues within the predicted peptide binding groove. Most CIA-resistant mouse strains share commonMa, M…
Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis.
1993
The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to …
Sequence analysis of the DRB1 promoter reveals limited polymorphism with no influence on gene expression.
2001
HLA-class II promoters contain a set of conserved regulatory regions necessary for constitutive and induced gene expression. For the HLA-DQB as well as for the DRB1 promoter sequence, polymorphisms with influence on gene expression have been reported. In contrast to these data we could show that there is very limited allele-specific polymorphism among the HLA-DRB1 promoter alleles. In a long range PCR we amplified a DNA sequence containing the promoter and the second exon of the DRB1 gene in one fragment. Nested PCR products of this PCR fragment for the promoter and for the second exon were analysed by DNA sequencing to allow the linkage of a promoter to its DR allele. Most investigated DRB…
Structural Manipulations of Marine Natural Products Inspire a New Library of 3-Amino-1,2,4-Triazine PDK Inhibitors Endowed with Antitumor Activity in…
2023
Pancreatic ductal adenocarcinoma (PDAC) is one of the main aggressive types of cancer, characterized by late prognosis and drug resistance. Among the main factors sustaining PDAC progression, the alteration of cell metabolism has emerged to have a key role in PDAC cell proliferation, invasion, and resistance to standard chemotherapeutic agents. Taking into account all these factors and the urgency in evaluating novel options to treat PDAC, in the present work we reported the synthesis of a new series of indolyl-7-azaindolyl triazine compounds inspired by marine bis-indolyl alkaloids. We first assessed the ability of the new triazine compounds to inhibit the enzymatic activity of pyruvate de…
Heterogeneity within and between primary colorectal carcinomas and matched metastases as revealed by analysis of Ki-ras and p53 mutations
2004
Analysis of the genetic status of Ki-ras and p53 in primary colorectal carcinomas and matched colorectal liver metastasis from 30 patients reveals an overall heterogeneity both within and between the two tumoral tissues. Both genes were found mutated with a similar frequency in both tissues; however, identical mutations in primary tumor and matched metastasis were found less frequently in the case of the Ki-ras than the p53 gene. Only in three cases the same p53 and Ki-ras mutations found in the primary tumor were found also in the metastasis. In several metastatic specimens the DNA bearing a mutation detected also in the primary tumor appears significantly less abundant than the wild-type …
Cytotoxic necrotizing factor type 2 produced by virulent Escherichia coli modifies the small GTP-binding proteins Rho involved in assembly of actin s…
1994
Cytotoxic necrotizing factor type 2 (CNF2) produced by Escherichia coli strains isolated from intestinal and extraintestinal infections is a dermonecrotic toxin of 110 kDa. We cloned the CNF2 gene from a large plasmid carried by an Escherichia coli strain isolated from a lamb with septicemia. Hydropathy analysis of the deduced amino acid sequence revealed a largely hydrophilic protein with two potential hydrophobic transmembrane domains. The N-terminal half of CNF2 showed striking homology (27% identity and 80% conserved residues) to the N-terminal portion of Pasteurella multocida toxin. Methylamine protection experiments and immunofluorescence studies suggested that CNF2 enters the cytosol…
Eksperimenti ar topoloģisko datu analīzi
2022
Maģistra darba mērķis ir iepazīstināt ar topoloģisko datu analīzi, kas ir pieeja datu kopu analīzei, izmantojot topoloģijas, kā matemātikas novirziena, metodes. Šī inovatīvā datu analīzes metode pasaulē pēdējos gados strauji attīstās un ar vien plašāk tiek pielietota, lai iegūtu informāciju no sarežģītiem, liela apjoma, daudzdimensionāliem datiem. Pašreiz nekur nav atrodams topoloģiskās datu analīzes apraksts un pielietojamība, latviešu valodā. Darbā tiek apskatīti divi dažādi uz topoloģiskās datu analīzes balstīti algoritmi - Mapper un ToMATo, kuru veiksmīgā izmantošanā noteicošais ir pareizu parametru izvēle. Darbā tiek pētītas un piedāvātas šo algoritmu parametru optimizācijas metodes un…
Biochemical properties of hepatitis C virus NS5B RNA-dependent RNA polymerase and identification of amino acid sequence motifs essential for enzymati…
1997
The NS5B protein of the hepatitis C virus (HCV) is an RNA-dependent RNA polymerase (RdRp) (S.-E. Behrens, L. Tomei, and R. De Francesco, EMBO J. 15:12-22, 1996) that is assumed to be required for replication of the viral genome. To further study the biochemical and structural properties of this enzyme, an NS5B-hexahistidine fusion protein was expressed with recombinant baculoviruses in insect cells and purified to near homogeneity. The enzyme was found to have a primer-dependent RdRp activity that was able to copy a complete in vitro-transcribed HCV genome in the absence of additional viral or cellular factors. Filter binding assays and competition experiments showed that the purified enzym…