Human TAF(II)135 potentiates transcriptional activation by the AF-2s of the retinoic acid, vitamin D3, and thyroid hormone receptors in mammalian cells.
We report for the first time the cloning of a complete cDNA encoding the human TFIID subunit hTAF(II)135 (hTAF(II)130). Full-length hTAF(II)135 comprises 1083 amino acids and contains two conserved domains present also in dTAF(II)110 and hTAF(II)105. We show that expression of hTAF(II)135 in mammalian cells strongly and selectively potentiates transcriptional stimulation by the activation function-2 (AF-2) of the retinoic acid, thyroid hormone, and vitamin D3 receptors (RAR, TR, and VDR), but does not affect the AF-2s of the estrogen (ER) or retinoid X (RXR) receptors. The coactivator activity requires an hTAF(II)135 region that is located between the conserved domains but is itself not conserved in dTAF(II)110 and hTAF(II)105. Expression of hTAF(II)135 also stimulates RAR AF-2 activity when a promoter with a low-affinity TATA element (TGTA) is used, indicating that hTAF(II)135 overexpression compensates for the low-affinity of TBP for this promoter and may facilitate the recruitment of TFIID by the RAR AF-2.
Mengus
G
G
Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale/Universite Louis Pasteur (CNRS/INSERM/ULP), Collège de France, Illkirch.
May
M
M
Carré
L
L
Chambon
P
P
Davidson
I
I
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002460:Cell Line; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism; D017930:Genes, Reporter; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D018167:Receptors, Calcitriol / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D011988:Receptors, Thyroid Hormone / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D016385:TATA Box; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism; D019473:Transcription Factors, TFII / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D018167:Receptors, Calcitriol; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; D011994:Recombinant Proteins; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII