The 'l(3)72Dj' (Taf4) complementation group comprises 4 EMS-induced mutant alleles.

dsRNA has been made from templates generated with primers directed against this gene.

dsRNA has been made from templates generated with primers directed against this gene. RNAi of Taf4 results in dorsal overextension of primary dendrites and a reduction in lateral branching. RNAi also causes defects in muscle, defects in dendrite morphogenesis and reproducible defects in da dendrite development.

The proteins encoded by Taf4, Taf5, Taf6, e(y)1 and Taf12 form a core sub-complex of TFIID. Of these, Taf4 protein plays the most critical role in maintaining stability of the TFIID complex.

The C-terminal domain of the Taf4 protein is necessary and sufficient for nucleating a holo-TFIID complex.

The proteins encoded by Taf1 and Taf4 have a specific role in transcription activation from TATA-less, downstream core promoter element (DPE)-containing promoters.

Area matching Drosophila TAF110 gene, Acc. No. L06861. Probable intron.

An interplay of dl and twi proteins with Taf4 protein is required for the activation of mesoderm-determining gene expression in the embryo.

Interacts, in vitro, with human thryroid-hormone receptor-β.

The products of the Taf4 and Taf6 loci serve as coactivators to mediate transcriptional activation by the bcd and hb enhancer binding proteins. A quadruple complex containing Tbp, Taf1, Taf4 and Taf6 mediates transcriptional synergism by bcd and hb, whereas triple Tbp-Taf complexes lacking one or other coactivator failed to support synergistic activation. The concerted action of multiple regulators with different coactivators helps to establish the pattern and level of segmentation gene transcription during development.

Mutagenesis studies in combination with protein binding experiments and reconstituted transcription reactions identified two independent activation domains of bcd that target different coactivator subunits (Taf4 and Taf6). Both coactivators are required for bcd to recruit the Tbp-Taf complex to the promoter and direct synergistic activation of transcription. Contact between multiple activation domains for bcd and different targets within the TfIID complex can mediate transcriptional synergism.

The assembly and purification of various functional Tbp TAF complexes demonstrate that Tbp plus the TAFs is sufficient to replace endogenous TFIID to support activated transcription in vitro.

TFIID subunit proteins and the Tbp protein can interact in pairwise combinations with several subunits in a network of interactions within TFIID.

The TFIID complex interacts with the promoters of Hsp70Bb, Hsp70Bc, Hsp26 and His3 making contacts at the TATA element, initiator, +18 and +28 regions.

Purified TAF80 is unable to bind TBP directly or to interact strongly with the C-terminal domain of TAF250, but can only interact with a complex containing TBP, TAF250, TAF110 and TAF60.

Cell culture studies suggest that TAF110 can functionally interact with Sp1 and serve as a coactivator of transcription.

A number of polypeptides (encoded by Taf1, Taf4, Taf5, Taf6, e(y)1 and Taf12) that are tightly associated with Tbp and are native TFIID components have been purified. Protein blotting experiments suggest that one of these proteins, Taf1, interacts directly with Tbp, while the association between Tbp and the other proteins is either weak or is an indirect association via Taf1.

In vitro expressed TAF110 interacts directly with the TAF250 which itself interacts with TBP, a complex of all three is suggested. Binding study with various mutants of Taf1 suggests that both TAF110 and TBP interact with the N-terminal 352-amino acid portion of TAF250.

Tbp, Taf1, Taf4 and Taf6 products can assemble into a mini-complex in vitro, showing that Taf6 and Taf4 occupy distinct binding sites on the C terminal part of Taf1.

The assembly of a partial complex containing recombinant TBF, TAF250 and TAF110 was reported. This triple complex supports activation of HeLa cell Sp1 and reveals specific interactions between Tbp, Taf1 and Taf4.