Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Initiation of transcription of protein-encoding genes by RNA polymerase II (Pol II) was thought to require transcription factor TFIID, a complex comprised of the TATA box-binding protein (TBP) and TBP-associated factors (TAF(II)s). In the presence of TBP-free TAF(II) complex (TFTC), initiation of Pol II transcription can occur in the absence of TFIID. TFTC containing the GCN5 acetyltransferase acetylates histone H3 in a nucleosomal context. We have identified a 130 kDa subunit of TFTC (SAP130) that shares homology with the large subunit of UV-damaged DNA-binding factor. TFTC preferentially binds UV-irradiated DNA, UV-damaged DNA inhibits TFTC-mediated Pol II transcription and TFTC is recruited in parallel with the nucleotide excision repair protein XP-A to UV-damaged DNA. TFTC preferentially acetylates histone H3 in nucleosomes assembled on UV-damaged DNA. In agreement with this, strong histone H3 acetylation occurs in intact cells after UV irradiation. These results suggest that the access of DNA repair machinery to lesions within chromatin may be facilitated by TFTC via covalent modification of chromatin. Thus, our experiments reveal a molecular link between DNA damage recognition and chromatin modification.
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PMID:UV-damaged DNA-binding protein in the TFTC complex links DNA damage recognition to nucleosome acetylation. 1140 95

Initiation of transcription of protein-encoding genes by RNA polymerase II was thought to require the transcription factor II D (TF(II)D), a complex comprising the TATA binding protein (TBP) and TBP-associated factors. However, another multiprotein complex isolated more recently and called TFTC (TBP-free TAF(II )containing complex), was shown to mediate initiation of RNA polymerase II (Pol II) transcription in the absence of TF(II)D as well as specific acetylation of histone H3 in a nucleosomal context. Several subunits of the TFTC complex were already identified using classical methods such as Edman based microsequencing and Western blot analysis. In this article we present a mass spectrometry based proteomic approach to confirm previous results and to identify other possible subunits of the TFTC complex. The TFTC complex was separated on one-dimensional sodium dodecyl sulfate polyacrylamide electrophoresis and analysed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and peptide mass fingerprinting. Identifications were realized after databank searches. This new characterization of TFTC complex confirmed the presence of already described subunits (TRRAP, GCN5, SAP130/KIA0017, TAF(II)150, TAF(II)135, TAF(II)100, TAF(II)80, TAF(II)20, SPT3 and PAF65beta). Moreover, a good coverage of these sequences was obtained. Interestingly, TAF(II)32 and PAF6alpha were also determined as potential novel subunits of TFTC. These results together show the suitability and the great potential of this method and offer new perspectives in fundamental studies of transcription factor complexes.
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PMID:Novel subunits of the TATA binding protein free TAFII-containing transcription complex identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry following one-dimensional gel electrophoresis. 1260 14