SUMO-1 modification of human transcription factor (TF) IID complex subunits: inhibition of TFIID promoter-binding activity through SUMO-1 modification of hsTAF5.
The TFIID complex is composed of the TATA-binding protein (TBP) and TBP-associated factors (TAFs) and is the only component of the general RNA polymerase II (RNAP II) transcription machinery with intrinsic sequence-specific DNA-binding activity. Binding of transcription factor (TF) IID to the core promoter region of protein-coding genes is a key event in RNAP II transcription activation and is the first and rate-limiting step of transcription initiation complex assembly. Intense research efforts in the past have established that TFIID promoter-binding activity as well as the function of TFIID-promoter complexes is tightly regulated through dynamic TFIID interactions with positive- and negative-acting transcription regulatory proteins. However, very little is known about the role of post-translational modifications in the regulation of TFIID. Here we show that the human TFIID subunits hsTAF5 and hsTAF12 are modified by the small ubiquitin-related modifier SUMO-1 in vitro and in human cells. We identify Lys-14 in hsTAF5 and Lys-19 in hsTAF12 as the primary SUMO-1 acceptor sites and show that SUMO conjugation has no detectable effect on nuclear import or intranuclear distribution of hsTAF5 and hsTAF12. Finally, we demonstrate that purified human TFIID complex can be SUMO-1-modified in vitro at both hsTAF5 and hsTAF12. We find that SUMO-1 conjugation at hsTAF5 interferes with binding of TFIID to promoter DNA, whereas modification of hsTAF12 has no detectable effect on TFIID promoter-binding activity. Our observations suggest that reversible SUMO modification at hsTAF5 contributes to the dynamic regulation of TFIID promoter-binding activity in human cells.
Boyer-Guittaut
Michaël
M
Transcription Laboratory, Marie Curie Research Institute, Oxted, Surrey RH8 0TL, UK.
Birsoy
Kivanç
K
Potel
Corinne
C
Elliott
Gill
G
Jaffray
Ellis
E
Desterro
Joanna M
JM
Hay
Ron T
RT
Oelgeschläger
Thomas
T
D000595:Amino Acid Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D004247:DNA / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D008239:Lysine / Q000737:chemistry; D008954:Models, Biological; D008957:Models, Genetic; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D025842:SUMO-1 Protein / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D035381:TATA-Binding Protein Associated Factors / Q000737:chemistry; D035362:Transcription Factor TFIID / Q000737:chemistry*; D014158:Transcription, Genetic; D014162:Transfection
D000939:Epitopes; D011994:Recombinant Proteins; D025842:SUMO-1 Protein; C470012:TAF12 protein, human; C100838:TAF5 protein, human; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D004247:DNA; D012319:RNA Polymerase II; D008239:Lysine