Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20226 (TATA-binding protein)
 1,297 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The proximal sequence element (PSE)-binding transcription factor (PTF) specifically recognizes the PSEs of both RNA polymerase II- and RNA polymerase III-transcribed small nuclear RNA (snRNA) genes. We previously have shown that PTF purified from human HeLa cells is a multisubunit complex of four polypeptides designated PTF alpha, -beta, -gamma, and -delta. We now report the isolation and expression of cDNAs encoding PTF gamma and PTF delta, as well as functional studies with cognate antibodies that recognize the native PTF complex in HeLa extracts. Immunoprecipitation studies confirm that the four PTF subunits originally found to copurify during conventional chromatography indeed form a tightly associated complex; they further show that the PTF so defined, including the gamma and delta subunits specifically, is essential for transcription of both class II and class III snRNA genes. Immunoprecipitation assays also show a weak substoichiometric association of the TATA-binding protein (TBP) with PTF, consistent with the previous report of a PTF-related complex (SNAPc) containing substoichiometric levels of TBP and a component (SNAPc43) identical in sequence to the PTF gamma reported here. Glutathione S-transferase pulldown assays further indicate relatively strong direct interactions of both recombinant PTF gamma and PTF delta with TBP, consistent either with the natural association of TBP with PTF in a semistable TBP-TBP-associated factor complex or with possible functional interactions between PSE-bound PTF and TATA-bound TBP during promoter activation. In addition, we show that in extracts depleted of TBP and TBP-associated factors, transcription from the U1 promoter is restored by recombinant TBP but not by TFIID or TFIIIB, indicating that transcription of class II snRNA genes requires a TBP complex different from the one used for mRNA-encoding genes.
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PMID:Cloning of two proximal sequence element-binding transcription factor subunits (gamma and delta) that are required for transcription of small nuclear RNA genes by RNA polymerases II and III and interact with the TATA-binding protein. 852 84

A new gene, RRN11, has been defined by certain rrn mutants of Saccharomyces cerevisiae which are defective specifically in the transcription of 35 S rRNA gene by RNA polymerase I (pol I). We have cloned the gene and found that it encodes a protein of 507 amino acids. We have used a strain with the chromosomal RRN11 deleted and carrying HA1 epitope-tagged RRN11 on a plasmid to isolate a protein complex containing the protein encoded by RRN11. This protein complex complemented rrn6 mutant extracts, which were previously shown to be deficient in the essential pol I transcription factor called Rrn6/7 complex or core factor (CF). The CF complex was previously shown to consist of three proteins, the 102- and 60-kDa subunits encoded by RRN6 and RRN7, respectively, and the 66-kDa subunit. The results of the above complementation experiments combined with mobility of Rrn11p in SDS-polyacrylamide gel electrophoresis analysis relative to Rrn6p and Rrn7p led to the conclusion that RRN11 encodes the 66-kDa subunit of CF. Glutathione S-transferase-Rrn11p fusion protein was found to bind strongly to 35S-labeled Rrn6p and Rrn7p but only weakly to 35S-labeled TATA-binding protein. Similarly, glutathione S-transferase-Rrn7p fusion protein bound strongly to 35S-labeled Rrn6p and Rrn11p but only weakly to 35S-labeled TATA-binding protein. These results are consistent with the fact that one can purify CF consisting of Rrn6p, Rrn7p, and Rrn11p from yeast cell extracts, but the purified complex does not contain TATA-binding protein. RRN11 was shown to be an essential gene, and [3H]uridine pulse experiments demonstrated directly that RRN11 is essential for rDNA transcription by pol I in vivo. Thus all three subunits of CF are essential for rDNA transcription. Because of the resemblance of CF to mammalian essential pol I transcription factor SL1, the amino acid sequences of Rrn11p and the other two subunits of CF were compared with those of the three TATA-binding protein-associated factors (TAFs) in the human SL1, TAFI48, TAFI63, and TAFI110. No significant similarity was detected between two sets of the proteins. Similarity as well as differences between CF and SL1 are discussed.
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PMID:RRN11 encodes the third subunit of the complex containing Rrn6p and Rrn7p that is essential for the initiation of rDNA transcription by yeast RNA polymerase I. 870 72