Search results for "Base Sequence"
showing 10 items of 1146 documents
The unique complexity of the CYP3A4 upstream region suggests a nongenetic explanation of its expression variability.
2010
The individually variable and unpredictable expression of CYP3A4 compromises therapies with 50% of contemporary drugs. Gene variants explain only a fraction of this variability.We investigated the evolution of CYP3A4 transcriptional regulation by nuclear receptors such as the xenobiotics sensors PXR and CAR.The combination of a proximal ER6 element with XREM and CLEM represents the original scheme of CYP3A regulation by nuclear receptors in placental mammals. Among human CYP3A genes, this scheme is retained only in CYP3A4, whereas non-CYP3A4 genes lost these elements to a variable extent during primate evolution. In parallel, the number of elements outside XREM and CLEM potentially responsi…
6-mercaptopurine and 9-(2-phosphonyl-methoxyethyl) adenine (PMEA) transport altered by two missense mutations in the drug transporter gene ABCC4
2008
Multiple drug resistance protein 4 (MRP4, ABCC4) belongs to the C subfamily of the ATP-binding cassette (ABC) transporter superfamily and participates in the transport of diverse antiviral and chemotherapeutic agents such as 6-mercaptopurine (6-MP) and 9-(2-phosphonyl methoxyethyl) adenine (PMEA). We have undertaken a comprehensive functional characterization of protein variants of MRP4 found in Caucasians and other ethnicities. A total of 11 MRP4 missense genetic variants (nonsynonymous SNPs), fused to green fluorescent protein (GFP), were examined in Xenopus laevis oocytes for their effect on expression, localization, and function of the transporter. Radiolabeled 6-MP and PMEA were chosen…
Development of type-specific and cross-reactive serological probes for the minor capsid protein of human papillomavirus type 33.
1993
Human papillomavirus type 33 (HPV33) is associated with malignant tumors of the cervix. In an attempt to develop immunological probes for HPV33 infections, antisera against various bacterial fusion proteins carrying sequences of the minor capsid protein encoded by L2 were raised in animals. Antigenic determinants on the HPV33 L2 protein were identified by using truncated fusion proteins and were classified as type specific or cross-reactive with respect to HPV1, -8, -11, -16, and -18. Cross-reactive epitopes map to amino acids 98 to 107 or to amino acids 102 to 112 and 107 to 117, respectively, depending on the fusion protein used for immunization. Antibodies directed toward these epitopes …
The yeast putative transcriptional repressor RGM1 is a proline-rich zinc finger protein.
1991
Abstract I have cloned a yeast gene, RGM1, which encodes a proline-rich zinc, finger protein. rgm1 mutants do not show any obvious phenotype but overexpression of RGM1 gene greatly impairs cell growth. The proline-rich region of RGM1 attached to a heterologous DNA binding domain is able to repress the expression of the target gene. RGM1 shares similar zinc finger motifs with the mammalian Egr (early growth response) proteins as well as proline-rich sequences with a high serine and threonine content, suggesting that RGM1 and Egr proteins could have functional similarities.
Production of biologically active light chain of tetanus toxin inEscherichia coli
1993
AbstractThe activity of the light (L) chain of tetanus toxin, and of mutants constructed by site-directed mutagenesis, was studied by expression and purification of the proteins from E. coli. Wild-type recombinant L chain (pTet87) was active in the inhibition of exocytosis from cultured bovine adrenal chromaffin cells, although at a level 5–15% of that of L chain purified from tetanus toxin. L chain mutants which terminated at Leu-438 (pTet89), or which contained a Cys-to-Ser mutation at residue 439 (pTet88) were equally as active as the full-length recombinant protein. The reduced activity of pTet87 L chain correlated with C-terminal proteolysis of the protein upon purification. A tryptic …
Mapping and structure of DMXL1, a human homologue of the DmX gene from Drosophila melanogaster coding for a WD repeat protein.
2000
The DmX gene was recently isolated from the X chromosome of Drosophila melanogaster. TBLASTN searches of the dbEST databases revealed sequences with a high level of similarity to DmX in a variety of different species, including insects, nematodes, and mammals showing that DmX is an evolutionarily highly conserved gene. Here we describe the cloning of the cDNA and the chromosomal localization of one of the human homologues of DmX, Dmx-like 1 (DMXL1). The human DMXL1 gene codes for a large mRNA of 11 kb with an open reading frame of 3027 amino acids. The putative protein belongs to the superfamily of WD repeat proteins, which have mostly regulatory functions. The DMXL1 protein contains an exc…
The putative sponge aggregation receptor. Isolation and characterization of a molecule composed of scavenger receptor cysteine-rich domains and short…
1998
Porifera (sponges) are the oldest extant metazoan phylum. Dissociated sponge cells serve as a classic system to study processes of cell reaggregation. The reaggregation of dissociated cells is mediated by an extracellularly localized aggregation factor (AF), based on heterophilic interactions of the third order; the AF bridges two cells by ligating a cell-surface-bound aggregation receptor (AR). In the present study we report cloning, expression and immunohistochemical localization of a polypeptide from the marine sponge Geodia cydonium, which very likely represents the AR. The presumed AR gene gives rise to at least three forms of alternatively spliced transcripts of 6.5, 4.9 and 3.9 kb, a…
Messenger RNA degradation is initiated at the 5′ end and follows sequence- and condition-dependent modes in chloroplasts
2011
Using reporter gene constructs, consisting of the bacterial uidA (GUS) coding region flanked by the 5' and 3' regions of the Chlamydomonas rbcL and psaB genes, respectively, we studied the degradation of mRNAs in the chloroplast of Chlamydomonas reinhardtii in vivo. Extending the 5' terminus of transcripts of the reporter gene by more than 6 nucleotides triggered rapid degradation. Placing a poly(G) tract, known to pause exoribonucleases, in various positions downstream of the 5' terminus blocked rapid degradation of the transcripts. In all these cases the 5' ends of the accumulating GUS transcripts were found to be trimmed to the 5' end of the poly(G) tracts indicating that a 5' → 3' exori…
The peroxisome proliferator response element (PPRE) present at positions -681/-669 in the rat liver 3-ketoacyl-CoA thiolase B gene functionally inter…
2000
Although previous data showed that the putative thiolase B PPRE located at -681/-669 bind the PPARalpha-RXRalpha heterodimer in vitro (Kliewer et al. (1992) Nature 358, 771-774), there is no evidence about the functional role of this element. By gel mobility-shift assay, we found an interaction of this PPRE with not only PPARalpha but also with HNF-4. By transfection of cells with the putative PPRE-driven luciferase reporter vector and PPARalpha, we found no significant activation of the luciferase gene expression, in contrast to the case with reporter expression driven by the PPRE of the peroxisomal bifunctional enzyme. On the other hand, HNF-4 activated the luciferase gene expression driv…
Cloning of a novel putative G-protein-coupled receptor (NLR) which is expressed in neuronal and lymphatic tissue.
1993
AbstractA novel G-protein-coupled receptor was isolated from mouse and rat neuronal and lymphatic tissues. The amino acid sequence of the rat receptor (rNLR) shows an overall homology of 80% to a recently cloned receptor from Burkitt's lymphoma cells (BLR1) which is exclusively expressed in lymphatic tissues [(1992) Eur. J. Immunol. 22, 2795]. Much less homology between rNLR and BLR1 was observed at the N-terminus (about 40%), whereas rNLR and the mouse homologue mNLR show 92% amino acid identity. Northern blot analysis of NLR revealed a predominant 5.5 kb mRNA species in various brain regions and neuronal cell lines, whereas in the spleen a 3 kb transcript is predominant. This distribution…