Disease relevance of Taf1

• The recombinant protein expressed in Sf9 cells via a baculovirus vector interacts directly with the 230-kDa subunit of TFIID (p230) [1].

High impact information on Taf1

• Here we report the cloning of Drosophila TAFII250 and the assembly of a partial complex containing recombinant TBP, TAFII110 and the C-terminal domain of TAFII250 [2].
• TAFII250 mediates monoubiquitination of histone H1 in vitro [3].
• Ubiquitin-activating/conjugating activity of TAFII250, a mediator of activation of gene expression in Drosophila [3].
• Point mutations within the putative ubac domain of TAFII250 abolished H1-specific ubiquitination in vitro [3].
• These phenotypes suggest roles for TAF250 in regulating the cell cycle, cell differentiation, cell proliferation, and cell survival [4].

Biological context of Taf1

• To examine the role of cell signaling in regulating alternative splicing, we analyzed the splicing of the Drosophila melanogaster TAF1 pre-mRNA [5].
• We demonstrate that TAF1 alternative splicing generates four mRNAs, TAF1-1, TAF1-2, TAF1-3, and TAF1-4, of which TAF1-2 and TAF1-4 encode proteins that directly bind DNA through AT hooks [5].
• While overexpression of any of several TAFs did not affect basal transcription, in either the presence or the absence of cotransfected dTBP, overexpression of TAFII230 inhibited transcriptional activation mediated by p53-GAL4 as well as by GAL4-VP16 and Sp1 [6].
• TAF1 alternative splicing was regulated in a tissue-specific manner and in response to DNA damage induced by ionizing radiation or camptothecin [5].
• Identification of highly conserved amino-terminal segments of dTAFII230 and yTAFII145 that are functionally interchangeable for inhibiting TBP-DNA interactions in vitro and in promoting yeast cell growth in vivo [7].

Anatomical context of Taf1

• The cannonball (can) gene of Drosophila encodes a homolog of a TBP-associated factor (dTAF5) protein expressed only in spermatocytes, where it is required for normal transcription of genes required for spermatid differentiation [8].

Associations of Taf1 with chemical compounds

• Recent work has shown that the two glutamine-rich activation domains of Sp1, A and B, can interact with at least one component of this complex, the TBP-associated factor dTAFII110 [9].
• TAF1 activates transcription by phosphorylation of serine 33 in histone H2B [10].

Enzymatic interactions of Taf1

• Here we report that histone H2B is phosphorylated at evolutionarily conserved Ser33 (H2B-S33) by the carboxyl-terminal kinase domain (CTK) of the Drosophila TFIID subunit TAF1 [10].

Other interactions of Taf1

• ATM and ATR Pathways Signal Alternative Splicing of Drosophila TAF1 Pre-mRNA in Response to DNA Damage [5].
• TATA-binding protein-associated factor 1 (TAF1) is an essential component of the general transcription factor IID (TFIID), which nucleates assembly of the preinitiation complex for transcription by RNA polymerase II [11].

References