High impact information on GTF2A2

• TFIID downstream interactions are thought to be functionally relevant because they can be induced by transcriptional activators, which in some cases requires TFIIA, result in stabilization of the TFIID-promoter complex, and correlate with increased recruitment of the remaining general transcription factors [1].
• Here we describe a novel pathway that requires an intact Inr and the Inr-binding factor TFII-I (ref. 3). Sequential addition of the general factors generated TFII-I-dependent preinitiation complexes different from those formed with TFIIA [2].
• Certain off-consensus TATA elements form poor binding sites for TBP and this compromised interaction interferes with higher order complex formation with TFIIA and/or TFIIB [3].
• Thus, a role for ALF in the assembly and stabilization of initiation complexes in germ cells is likely to be similar or identical to the role of TFIIA in somatic cells [4].
• A subset of these TFIIA-gamma mutations disrupted transcriptional activation by all activators tested, except for the Epstein-Barr virus-encoded Zta protein [5].

Biological context of GTF2A2

• Searches of the human genome sequence database using the basic local alignment search tool reveal that the ALF and TFIIAalpha/beta(GTF2A1) genes are both composed of nine exons, whereas the TFIIAgamma (GTF2A2) gene is composed of five exons [6].
• The general transcription factor IIA (TFIIA) binds to the TATA binding protein (TBP) and mediates transcriptional activation by distinct classes of activators [5].
• As was shown previously for TFIID, TFIIA is the second basal transcription factor which could be demonstrated to be involved in gene expression by two different RNA polymerases [7].
• Interactions of TFIIA with DNA upstream of the TATA box did not appear to play a major role in stabilizing TBP/TATA interactions [8].

Anatomical context of GTF2A2

• Transactivation of the human T-cell lymphotropic virus type 1 Tax1-responsive 21-base-pair repeats requires Holo-TFIID and TFIIA [9].

Associations of GTF2A2 with chemical compounds

• The stability of TFIIA/TBP interactions was measured using a rapid "pull-down" assay, which employed-nickel agarose and polyhistidine-tagged TFIIA [8].
• Farwestern analyses and glutathione S-transferase interaction assays demonstrated that MBF2 makes a direct contact with the beta-subunit of TFIIA [10].

Other interactions of GTF2A2

• Interactions were also detected between full-length HSF1 and the small subunit (gamma) of TFIIA [11].
• We propose that Tax1 utilizes a transactivation pathway involving the activator regulated basal transcription factors TFIID and TFIIA [9].
• TFIIA is required for in vitro transcription of mammalian U6 genes by RNA polymerase III [7].

Analytical, diagnostic and therapeutic context of GTF2A2

• Instead, the upstream DNA contacts appeared to be important for stabilizing the association of TFIIA with the TBP/TATA complex as measured in electrophoretic mobility shift assays: koff of TFIIA decreased from 1.4(+/-0.1) x 10(-3) s-1 (t1/2 = eight minutes) to 2.4(+/-0.2) x 10(-4) s-1 (t1/2 = 49 minutes) when upstream DNA contacts were allowed [8].

References