TAFII55 binding to TAFII250 inhibits its acetyltransferase activity.
The general transcription factor, TFIID, consists of the TATA-binding protein (TBP) associated with a series of TBP-associated factors (TAFs) that together participate in the assembly of the transcription preinitiation complex. One of the TAFs, TAF(II)250, has acetyltransferase (AT) activity that is necessary for transcription of MHC class I genes: inhibition of the AT activity represses transcription. To identify potential cellular factors that might regulate the AT activity of TAF(II)250, a yeast two-hybrid library was screened with a TAF(II)250 segment (amino acids 848-1279) that spanned part of its AT domain and it's the domain that binds to the protein, RAP74. The TFIID component, TAF(II)55, was isolated and found to interact predominantly with the RAP74-binding domain. TAF(II)55 binding to TAF(II)250 inhibits its AT activity. Importantly, the addition of recombinant TAF(II)55 to in vitro transcription assays inhibits TAF(II)250-dependent MHC class I transcription. Thus, TAF(II)55 is capable of regulating TAF(II)250 function by modulating its AT activity.
Gegonne
A
A
Experimental Immunology Branch, Building 10, Room 4B-36, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Weissman
J D
JD
Singer
D S
DS
D000107:Acetylation; D000123:Acetyltransferases / Q000037:antagonists & inhibitors*; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006367:HeLa Cells; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D051548:Histone Acetyltransferases; D006801:Humans; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D015534:Trans-Activators / Q000378:metabolism / Q000494:pharmacology*; D035362:Transcription Factor TFIID
D004268:DNA-Binding Proteins; D015395:Histocompatibility Antigens Class I; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; C091537:TAF7 protein, human; D035381:TATA-Binding Protein Associated Factors; D015534:Trans-Activators; D035362:Transcription Factor TFIID; D000123:Acetyltransferases; D051548:Histone Acetyltransferases; C069001:TATA-binding protein associated factor 250 kDa