Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.6 (RNA polymerase)
34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Levels of mRNA and protein encoded by the TATA-binding protein (tbp) gene are shown to increase dramatically during late spermatogenesis in rodents, culminating in a highly testis-enriched expression pattern. Whereas adult spleen and liver contained roughly 0.7 and 2.3 molecules of TBP mRNA per haploid genome-equivalent, respectively, adult testis contained 80-200 molecules of TBP mRNA per haploid genome-equivalent. Comparison of nuclear and cytoplasmic levels of TBP mRNA in liver and testis suggested that nuclear events (transcription or processing) contribute roughly 12-fold, and cytoplasmic events (mRNA stability) roughly 6-fold, to testis-specific overaccumulation. Levels of nuclear TBP protein in testis cells were, on average, 8- and 11-fold higher than those in liver and spleen cells, respectively. Overexpression of TBP mRNA in testis began about 20 days after birth and reached a plateau around day 40, corresponding to the developmental emergence of haploid cells. Besides TBP, two other components of the general RNA polymerase II machinery, TFIIB and RNA polymerase II, were also overexpressed in testis. By immunostaining, it was found that TBP and RNA polymerase II were particularly rich in round spermatid nuclei. Our results suggest a molecular explanation for how early spermatids are able to accumulate all of the mRNA necessary for the final week of spermiogenesis.
...
PMID:High accumulation of components of the RNA polymerase II transcription machinery in rodent spermatids. 767 3

The testis-specific human sperm antigen, SP-10, has been designated a 'primary vaccine candidate' by the World Health Organization Taskforce on Contraceptive Vaccines. Molecular cloning and sequencing of the cDNAs coding for human (h) and baboon (b) SP-10 have been reported. To produce large amounts of pure antigen for ongoing studies of the immunogenicity and anti-fertility effects of SP-10, we used an efficient Escherichia coli expression system. The full-length open reading frames for hSP-10 and bSP-10 were placed under the inducible T7 bacteriophage RNA polymerase/promoter system. An in-frame fusion was made such that a His6 stretch was produced at the C terminus of SP-10. Upon induction of gene expression, large amounts of hSP-10 or bSP-10 were synthesized and the recombinant (re-) protein segregated into an insoluble fraction. The protein was then solubilized in 6 M guanidine.HCl and purified by immobilized metal affinity chromatography (IMAC). The yield of purified bSP-10 preparation was approx. 20 micrograms/ml of culture. Immunoreactivity of the purified re-SP-10 with MHS-10, a monoclonal antibody specific to SP-10, and rabbit polyclonal sera raised against SP-10, indicated that the synthesized antigen was suitable for immunization studies. Four female baboons were then immunized with the re-bSP-10 antigen. Immunoblots using pre-immune and immune sera from these animals indicated that all four baboons produced antibodies that reacted with native SP-10 extracted from human sperm in a manner identical to that of MHS-10, the positive control. Immune sera also stained the acrosome region of human and baboon sperm heads by immunofluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Production in Escherichia coli, purification and immunogenicity of acrosomal protein SP-10, a candidate contraceptive vaccine. 792 98

A new S-II cDNA clone was isolated from a rat testis library. This cDNA contained an open reading frame encoding 299 amino acid residues. The deduced amino- and carboxyl-terminal regions were very similar with those of Ehrlich cell S-II, which we reported previously, but the sequence of the intervening 46 amino acid residues was unique. This new S-II was expressed in the testis but not in the other rat tissues examined, suggesting that it was a testis-specific S-II. Recombinant testis-specific S-II produced in Escherichia coli was shown to stimulate RNA polymerase II.
...
PMID:Cloning and identification of testis-specific transcription elongation factor S-II. 830 Jun 45

Murine heme oxygenase-2 (HO-2) cDNA sequences were determined through the assembly of mouse expressed sequence tag (EST) sequences using the rat HO-2 sequence as a template. The sequence analysis revealed two mRNA isoforms, probably arising through alternative splicing, which differed in their 5'-untranslated region (UTR), and were named HO-2a and HO-2b. One EST sequence included an extended 3'-UTR and suggested there may be a choice of poly-adenylation (poly-A) signal sequence. Reverse transcriptase polymerase chain reaction (PCR) suggested that HO-2a mRNA may be specifically expressed in the testis, while HO-2b mRNA was present in all tissues analysed. Furthermore, HO-2a and HO-2b transcripts were both found to include the extended 3'-UTR, but these transcripts were detected only in the testis. Northern analysis of a greater range of tissues confirmed the testis-specific expression of HO-2a mRNA and suggested that the transcripts which included the extended 3'-UTR were a small minority of the HO-2 mRNA population. These alternative murine HO-2 transcripts suggest that mechanisms such as mRNA transport, translational efficiency or mRNA turnover may be implicated in the regulation of HO-2 gene expression, most notably in the testis.
...
PMID:The identification and expression of heme oxygenase-2 alternative transcripts in the mouse. 979 3

hnRNP A2/B1 proteins are among the most abundant pre-mRNA-binding proteins of vertebrates and structurally similar to hnRNP A1. We have produced two specific monoclonal antibodies against A2 and B1 and studied their molecular characteristics and in vivo expression in rat tissues. Immunoprecipitation demonstrated that the hnRNP A2/B1 complexes contain many snRNP (small nuclear ribonucleoprotein) proteins, consistent with their role in pre-mRNA splicing. RNA polymerase II inhibition causes nucleocytoplasmic shuttling of A2 and B1. In most tissues, they are localized in the nucleus; however, in the squamous epithelium of the skin and esophagus A2 is also distributed in the cytoplasm. The relative amounts of A2 and B1 are not constant among different tissues. In the adrenal, only A2 is extremely abundant in the medulla but not in the cortex. In the testis the expression of A2 and B1 are observed through spermatogenesis, and different from A1 which is stringently repressed in spermatocytes. We also found and cloned a novel testis-specific isoform of A2/B1, namely hnRNP B0. The difference of expression of A2, B1, and A1 provides new information on their in vivo roles. The diversity of A/B group hnRNP proteins may have important effects on the posttranscriptional regulation of cell-specific gene expression.
...
PMID:Molecular characterization of the hnRNP A2/B1 proteins: tissue-specific expression and novel isoforms. 992 56

The general transcription factor IIA (TFIIA) stimulates RNA polymerase II-specific transcription by stabilizing the association of the TATA-binding protein (TBP) with promoter DNA, inhibiting repressors of TBP, and facilitating activator-dependent conformational changes in the preinitiation complex. TFIIA is encoded by two genes (alphabeta and gamma) that are highly conserved between human and yeast. Here, we report the molecular cloning of a novel human gene that shares significant sequence similarity to the evolutionarily conserved amino- and carboxyl-terminal domains of TFIIAalphabeta. The TFIIA-related protein (TFIIAtau) was cloned from a testis-specific cDNA library, and its mRNA is expressed predominantly in testis tissue as determined by expressed sequence tag data base analysis and Northern blotting analysis. The TFIIA complex reconstituted with the testis-specific subunit, TFIIA (tau+gamma), formed the TFIIA-TBP-TATA DNA (T-A) and TFIIA-TFIIB-TBP-TATA DNA (TAB) complexes indistinguishably from TFIIA (alphabeta+gamma). TFIIA (tau+gamma) supported basal and activated transcription for most activators in reactions reconstituted with TFIIA-depleted nuclear extracts. However, TFIIA (tau+gamma) was reduced relative to TFIIA (alphabeta+gamma) for stimulating transcription with at least one activator, suggesting that these two forms of TFIIA have activator specificity. These results suggest that TFIIAtau may be important for testis-specific transcription regulation.
...
PMID:A testis-specific transcription factor IIA (TFIIAtau) stimulates TATA-binding protein-DNA binding and transcription activation. 1061 94

The Elongin complex stimulates the rate of transcription elongation by RNA polymerase II by suppressing the transient pausing of the polymerase at many sites along the DNA template. Elongin is composed of a transcriptionally active A subunit and two small regulatory B and C subunits, the latter of which bind stably to each other to form a binary complex that interacts with Elongin A and strongly induces its transcriptional activity. To further understand the roles of Elongin in transcriptional regulation, we attempted to identify Elongin-related proteins. Here, we report on the cloning, expression, and characterization of human Elongin A2, a novel transcription elongation factor that exhibited 47% identity and 61% similarity to Elongin A. Biochemical studies have shown that Elongin A2 stimulates the rate of transcription elongation by RNA polymerase II and is capable of forming a stable complex with Elongin BC. However, in contrast to Elongin A, its transcriptional activity is not activated by Elongin BC. Northern blot analysis revealed that Elongin A2 mRNA was specifically expressed in the testis, suggesting that Elongin A2 may regulate the transcription of testis-specific genes.
...
PMID:Identification and characterization of Elongin A2, a new member of the Elongin family of transcription elongation factors, specifically expressed in the testis. 1069 60

The human ELL gene, which is a frequent target for translocation in acute myeloid leukemia, was initially isolated from rat liver nuclei and found to be an RNA polymerase II elongation factor. Based on homology to ELL, we later cloned ELL2 and demonstrated that it can also increase the catalytic rate of transcription elongation by RNA polymerase II. To better understand the role of ELL proteins in the regulation of transcription by RNA polymerase II, we have initiated a search for proteins related to ELLs. In this report, we describe the molecular cloning, expression, and characterization of ELL3, a novel RNA polymerase II elongation factor approximately 50% similar to both ELL and ELL2. Our transcriptional studies have demonstrated that ELL3 can also increase the catalytic rate of transcription elongation by RNA polymerase II. The C-terminal domain of ELL, which we recently demonstrated to be required and sufficient for the immortalization of myeloid progenitor cells, shares strong similarities to the C-terminal domain of ELL3. ELL3 was localized by immunofluorescence to the nucleus of cells, and Northern analysis indicated that ELL3 is a testis-specific RNA polymerase II elongation factor.
...
PMID:Identification, cloning, expression, and biochemical characterization of the testis-specific RNA polymerase II elongation factor ELL3. 1088 41

Heterogeneous nuclear ribonucleoproteins (hnRNPs) A2 and B1 are abundant nuclear proteins that bind to nascent RNAs synthesized by RNA polymerase II. Previously we had found that the splicing isoforms hnRNP B0a/b, from which the ninth exon of the A2/B1 gene is excluded, are abundantly expressed in testis. We postulated that B0a/b are testis-specific isoforms, and investigated the expression of A2/B1 and B0a/b in rat tissues and in postnatal development of rat testes using RNase protection assay, immunoblotting, and immunohistochemistry. We found that hnRNP B0a/b mRNAs are expressed in several tissues but that the testis alone expresses B0a/b proteins. A sequential study using neonatal rat testes demonstrated that B0a/b mRNAs are produced after 17 days of age, but not translated until 4 weeks of age when round spermatids appear in addition to spermatogonia and spermatocytes. Immunohistochemically, hnRNP A2/B1 isoforms are expressed during spermatogenesis from spermatogonia through round spermatids, whereas the expression of A1 is restricted to spermatogonia. This expression pattern in the rat testis is maintained from birth through adulthood. These results suggest that the expression of the hnRNP A2/B1 gene is partly regulated by a testis-specific post-transcriptional mechanism, and that the products of the A2/B1 gene, especially hnRNP B0a/b, are involved in spermatogenesis.
...
PMID:Testis- and developmental stage-specific expression of hnRNP A2/B1 splicing isoforms, B0a/b. 1097 4

The rat Hst70 gene and its mouse counterpart Hsp70.2 belong to the family of Hsp70 heat shock genes and are specifically expressed in male germ cells. Previous studies regarding the structure of the 5' region of the transcription unit of these genes as well as localization of the 'cis' elements conferring their testis-specific expression gave contradictory results [Widlak, Markkula, Krawczyk, Kananen and Huhtaniemi (1995) Biochim. Biophys. Acta 1264, 191-200; Dix, Rosario-Herrle, Gotoh, Mori, Goulding, Barret and Eddy (1996) Dev. Biol. 174, 310-321]. In the present paper we solve these controversies and show that the 5' untranslated region (UTR) of the Hst70 gene contains an intron which is localized similar to that of the mouse Hsp70.2 gene. Reverse transcriptase-mediated PCR, Northern blotting and RNase protection analysis revealed that the transcription initiation of both genes starts at two main distant sites, and one of them is localized within the intron. As a result two populations of Hst70 gene transcripts with similar sizes but different 5' UTR structures can be detected in total testicular RNA. Functional analysis of the Hst70 gene promoter in transgenic mice and transient transfection assays proved that the DNA fragment of approx. 360 bp localized upstream of the ATG transcription start codon is the minimal promoter required for testis-specific expression of the HST70/chloramphenicol acetyltransferase transgene. These experiments also suggest that the expression of the gene may depend on 'cis' regulatory elements localized within exon 1 and the intron sequences.
...
PMID:Structure of the 5' region of the Hst70 gene transcription unit: presence of an intron and multiple transcription initiation sites. 1156 76


1 2 3 Next >>

---