Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The detergent-soluble extract of rat ovary plasma membranes contained a Gs protein of about 100 kDa as shown by its elution behavior on a Bio Gel A-1.5m column. However, the cell membranes exposed to hCG (37 degrees C, 15 min) contained in addition a higher molecular weight Gs protein complex of 300 kDa comprised of human chorionic gonadotropin (hCG) receptor (hCGR) and Gs. The complex bound with an affinity column of GTP-Sepharose and could be released with Gpp(NH)p and GTP inhibited this binding. The presence of the hCGR in the complex was shown by its binding to 125I-hCG. Furthermore, GTP inhibited the binding of hCG to the complex. These results indicate the presence of hCGR and Gs protein complex in the hCG-treated membranes. hCGR and Gs protein were individually purified and reconstituted into phospholipid vesicles. The protein-phospholipid vesicles showed saturation kinetics of binding of 125I-hCG and 3H-Gpp(NH)p. Incubation of phospholipid vesicles with hCG resulted in a 2-3-fold increase in the binding of 3H-Gpp(NH)p and GTPase activity. Activation of Gs protein was dependent on the length of incubation and the hormone concentration. Deglycosylated hCG was about 10 times less potent than hCG suggesting a role of carbohydrates of hCG in inducing hCG-Gs protein interactions. The data with the in vitro reconstitution system rule out the involvement of a carbohydrate-binding lectin in the function of the hormone.
Mol Cell Endocrinol 1991 Sep
PMID:Human choriogonadotropin-induced coupling of receptor and Gs protein and the effect of hormone deglycosylation. 195 70

Fragments of the rat ferritin-H 5'-flanking region up to 1 kilobase in length were generated by the polymerase chain reaction using FRTL5 rat thyroid cell genomic DNA as template. Ferritin-H 5'-flanking region fragments of 219, 351, 666, and 1046 basepairs (bp), ligated up-stream to the reporter gene luciferase, were transiently transfected into FRTL5 thyroid cells and NIH-3T3 mouse fibroblasts. In both cell types, constitutive (nonstimulated) ferritin-H promoter activity increased progressively with constructs containing increasing lengths of 5'-flanking region. TSH or (Bu)2cAMP (dBcAMP) stimulation of FRTL5 cells transfected with the shorter (219 and 351 bp) ferritin-H 5'-flanking region fragments increased promoter activity 2- to 3-fold. However, with the longer DNA segments (666 and 1046 bp), the extent of TSH stimulation was less. Exposure of transfected NIH-3T3 cells to dBcAMP mimicked in all respects the effects of TSH and dBcAMP on ferritin-H promoter activity in FRTL5 cells. Transcription initiation sites in the luciferase reporter gene were unaffected by the length of the ferritin-H 5'-flanking region included in the construct or by dBcAMP stimulation. Plasmid constructs with 45 bp of the ferritin-H 5'-flanking region containing a potential cAMP response element did not reveal any promoter activity or dBcAMP responsiveness in this region. Gel shift mobility assays with the -219 bp ferritin-H 5'-flanking region fragment and NIH-3T3 nuclear proteins revealed specific protein-DNA interaction. Reduced DNA mobility was inhibited by excess unlabeled probe DNA, but not by DNA fragments corresponding to the recognition sites for a variety of known trans-activating factors.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1990 Aug
PMID:Thyrotropin and adenosine 3',5'-monophosphate stimulate the activity of the ferritin-H promoter. 196 70

A new B-cell-specific enhancer element has been identified 3' of E4 and the octamerlike motifs in the human immunoglobulin heavy-chain gene enhancer. Tandem copies of this 67-bp MnlI-AluI fragment, when fused to the chloramphenicol acetyltransferase gene driven by the conalbumin promoter, stimulated transcription in B cells but not in Jurkat T cells or HeLa cells. Footprinting analysis revealed that the identical sequence CCGAAACTGAAAAGG, designated E6, was protected by nuclear extracts from B cells, T cells, or HeLa cells. Gel mobility shift assays using a synthetic E6 motif detected a B-cell-specific complex in addition to a ubiquitous band found also in T cells and HeLa cells. In agreement with the results of gel retardation assays, tandem copies of the E6 motif stimulated transcription in ARH77 and Raji cells but not in Jurkat or HeLa cells. Furthermore, a mutant E6 motif lost both in vitro binding activity and in vivo enhancer activity. In striking contrast to the mouse Ig heavy-chain enhancer, in which the octamer motif acts as a B-cell-specific enhancer element, the human enhancer contains an octamerlike sequence with one base substitution which bound octamer-binding proteins with only very low affinity and showed no enhancer activity of its own. Interestingly, the MnlI-AluI fragment could suppress the basal-level activity of the conalbumin promoter in both Jurkat and HeLa cells. Moreover, simian virus 40 enhancer activity was blocked by the MnlI-AluI fragment in HeLa cells but not in B cells. Thus, the novel enhancer element identified in this study is probably a target site for both positive and negative factors.
Mol Cell Biol 1991 Jan
PMID:Positive and negative regulation of immunoglobulin gene expression by a novel B-cell-specific enhancer element. 198 54

The PHO8 gene of Saccharomyces cerevisiae encodes repressible alkaline phosphatase (rALPase; EC 3.1.3.1). The rALPase activity of the cells is two to three times higher in medium containing a low concentration of Pi than in high-Pi medium due to transcription of PHO8. The Pi signals are conveyed to PHO8 by binding of PHO4 protein, a positive regulatory factor, to a promoter region of PHO8 (PHO8p) under the influence of the PHO regulatory circuit. Deletion analysis of PHO8p DNA revealed two separate regulatory regions required for derepression of rALPase located at nucleotide positions -704 to -661 (distal region) and -548 to -502 (proximal region) and an inhibitory region located at -421 to -289 relative to the translation initiation codon. Gel retardation experiments showed that a beta-galactosidase-PHO4 fusion protein binds to a 132-bp PHO8p fragment bearing the proximal region but not to a 226-bp PHO8 DNA bearing the distal region. The fusion protein also binds to a synthetic oligonucleotide having the same 12-bp nucleotide sequence as the PHO8p DNA from positions -536 to -525. The 132-bp PHO8p fragment, connected at position -281 of the 5' upstream region of a HIS5'-'lacZ fused gene, could sense Pi signals in vivo, but a 20-bp synthetic oligonucleotide having the same sequence from -544 to -525 of the PHO8p DNA could not. Linker insertions in the PHO8p DNA indicated that the 5-bp sequence 5'-CACGT-3' from positions -535 to -531 is essential for binding the beta-galactosidase-PHO4 fusion protein and for derepression of rALPase.
Mol Cell Biol 1991 Feb
PMID:Specific cis-acting sequence for PHO8 expression interacts with PHO4 protein, a positive regulatory factor, in Saccharomyces cerevisiae. 199 Feb 83

A human cell line selected for cisplatin resistance (CPR) was irradiated with UV light and showed cross-resistance to UV light. Applying a modified chloramphenicol acetyltransferase assay, we observed that CPR cells acquired enhanced host cell reactivation of a transfected plasmid carrying UV damage. Gel mobility shift analysis indicated that two nuclear factors that recognize UV-modified DNA were overexpressed in CPR cells. In addition, factors that bind UV-modified DNA were independent from the factors that bind cisplatin-modified DNA. The significance of the identified binding factors, possibly DNA repair enzymes, is discussed.
Mol Cell Biol 1991 Apr
PMID:Cross-resistance to UV radiation of a cisplatin-resistant human cell line: overexpression of cellular factors that recognize UV-modified DNA. 200 98

Gene product 33 of phage T4 is known to be essential in late transcription. Upstream from gene 33 and overlapping its 5' terminal sequence by 20 bp, we identified an open reading frame coding for a binding protein for double-stranded DNA (DsbA). Gene product DsbA is composed of 89 amino acid residues with a Mr of 10376 kDa. We purified this protein to homogeneity from over-expressing cells. Gel retardation assays reveal that it binds to DNA and footprint analyses disclose that it interacts preferentially with T4 late promoter regions. At the sites of binding the protein introduces nicks in double-stranded DNA. In vitro transcription assays performed with T4 late modified RNA polymerase on restriction fragments harbouring a T4 late promoter region prove that gene product DsbA enhances transcription from these promoter regions in the presence of gene product 33. Gene dsbA is distinct from gene das which maps close to this genomic region.
Mol Gen Genet 1991 Mar
PMID:Gene product dsbA of bacteriophage T4 binds to late promoters and enhances late transcription. 201 38

The endogenous chicken vitellogenin II (VTGII) gene is transcribed exclusively in hepatocytes in response to estrogen. We previously identified two estrogen response elements (EREs) upstream of this gene. We now present an analysis of the VTGII promoter activated by these EREs in response to estrogen. Chimeric VTGII-CAT genes were cotransfected into LMH chicken hepatoma cells along with an estrogen receptor expression vector, and transient CAT expression was assayed after culturing the cells in the absence or presence of estrogen. An analysis of constructs bearing deletions downstream of the more proximal ERE indicated that promoter elements relevant to transcription in LMH cells extend to between -113 and -96. The relative importance of sequences within the VTGII promoter was examined by using 10 contiguous linker scanner mutations spanning the region from -117 to -24. Although most of these mutations compromised VTGII promoter function, one dramatically increased expression in LMH cells and also rendered the VTGII promoter capable of being activated by cis-linked EREs in fibroblasts cotransfected with an estrogen receptor expression vector. Gel retardation and DNase I footprinting assays revealed four factor-binding sites within this promoter. We demonstrate that three of these sites bind C/EBP, SP1, and USF (or related factors), respectively; the fourth site binds a factor that we denote TF-V beta. The biological relevance of these findings is suggested by the fact that three of these binding sites map to sites previously shown to be occupied in vivo in response to estrogen.
Mol Cell Biol 1991 May
PMID:Mutational studies reveal a complex set of positive and negative control elements within the chicken vitellogenin II promoter. 201 74

There is a region in the mouse histone H3 gene protein-encoding sequence required for high expression. The 110-nucleotide coding region activating sequence (CRAS) from codons 58 to 93 of the H3.2 gene restored expression when placed 520 nucleotides 5' of the start of transcription in the correct orientation. Since identical mRNA molecules are produced by transcription of the original deletion gene and the deletion gene with the CRAS at -520, effects of the deletions on mRNA stability or other posttranscriptional events are completely ruled out. Inversion of the CRAS sequence in its proper position in the H3 gene resulted in only a threefold increase in expression, and placing the CRAS sequence 5' of the deleted gene in the wrong orientation had no effect on expression. In-frame deletions in the coding region of an H2a.2 gene led to identification of a 105-nucleotide sequence in the coding region between amino acids 50 and 85 necessary for high expression of the gene. Additionally, insertion of the H3 CRAS into the deleted region of the H2a.2 gene restored expression of the H2a gene. Thus, the CRAS element has an orientation-dependent, position-independent effect. Gel mobility shift competition studies indicate that the same proteins interact with both the H3 and H2a CRAS elements, suggesting that a common factor is involved in expression of histone genes.
Mol Cell Biol 1991 Jun
PMID:A common transcriptional activator is located in the coding region of two replication-dependent mouse histone genes. 203 12

The myosin light chain (MLC) 1/3 enhancer (MLC enhancer), identified at the 3' end of the skeletal MLC1/3 locus, contains a sequence motif that is homologous to a protein-binding site of the skeletal muscle alpha-actin promoter. Gel shift, competition, and footprint assays demonstrated that a CArG motif in the MLC enhancer binds the proteins MAPF1 and MAPF2, previously identified as factors interacting with the muscle regulatory element of the skeletal alpha-actin promoter. Transient transfection assays with constructs containing the chloramphenicol acetyltransferase reporter gene demonstrated that a 115-bp subfragment of the MLC enhancer is able to exert promoter activity when provided with a silent nonmuscle TATA box. A point mutation at the MAPF1/2-binding site interferes with factor binding and abolishes the promoter activity of the 115-bp fragment. The observation that an oligonucleotide encompassing the MAPF1/2 site of the MLC enhancer alone cannot serve as a promoter element suggests that additional factor-binding sites are necessary for this function. The finding that MAPF1 and MAPF2 recognize similar sequence motifs in two muscle genes, simultaneously activated during muscle differentiation, implies that these factors may have a role in coordinating the activation of contractile protein gene expression during myogenesis.
Mol Cell Biol 1991 Jul
PMID:The myosin light chain enhancer and the skeletal actin promoter share a binding site for factors involved in muscle-specific gene expression. 204 75

Fv fragments of four monoclonal antibodies specific for morphine binding have been produced from their divalent IgG forms by papain digestion using the classic procedure for Fab formation. The binding characteristics of one of the Fv fragments have been determined relative to the intact antibody by equilibrium dialysis. Its dissociation constant is a factor of five lower than the IgG. Previous work had resulted in the sequences of each the chains for the four Fv fragments. The light chains are all from the highly homologous lambda subclass while the gamma heavy chains are closely related except for their CDR regions. In this work optical molar extinction coefficients are predicted from amino acid sequences for each of the fragments. It is found that they differ significantly from each other and from the commonly used value for intact IgG. Detailed comparisons between our results and those reported previously on the molecular masses of Fv-derived light and heavy chains and hapten-Fv dissociation constants are given based on analytical gel electrophoresis and electroblotting experiments using dye and immunovisualization techniques. Isoelectric focusing experiments have been performed and the pIs obtained are compared to those predicted theoretically from the chain sequences. Gel filtration column chromatography, acrylamide gel electrophoresis and equilibrium dialysis experiments are consistent with significant aggregation of the Fv fragments in neutral solution with accompanying inactivation of the binding site. Comparison of sequences for the Fv light and heavy chains are made with those which have been proposed to be important for chain dimer association and for canonical hypervariable regions. This methods of Fv production is not regarded as a general one. However, it may be an approach which is general to lambda chain containing antibodies.
Mol Immunol
PMID:Direct production of Fv-fragments from a family of monoclonal IgGs papain digestion. 206 18


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