A facelift for the general transcription factor TFIIA.
TFIIA was classified as a general transcription factor when it was first identified. Since then it has been debated to what extent it can actually be regarded as "general". The most notable feature of TFIIA is the proteolytical cleavage of the TFIIAalphabeta into a TFIIAalpha and TFIIAbeta moiety which has long remained a mystery. Recent studies have showed that TFIIA is cleaved by Taspase1 which was initially identified as the protease for the proto-oncogene MLL. Cleavage of TFIIA does not appear to serve as a step required for its activation as the uncleaved TFIIA in the Taspase1 knock-outs adequately support bulk transcription. Instead, cleavage of TFIIA seems to affect its turn-over and may be a part of an intricate degradation mechanism that allows fine-tuning of cellular levels of TFIIA. Cleavage might also be responsible for switching transcription program as the uncleaved and cleaved TFIIA might have distinct promoter specificity during development and differentiation. This review will focus on functional characteristics of TFIIA and discuss novel insights in the role of this elusive transcription factor.
Høiby
Torill
T
NCMLS, Department of Molecular Biology, 191, Radboud University of Nijmegen, PO Box 91001, 6500 HB Nijmegen, The Netherlands.
Zhou
Huiqing
H
Mitsiou
Dimitra J
DJ
Stunnenberg
Hendrik G
HG
D000595:Amino Acid Sequence; D000818:Animals; D010450:Endopeptidases / Q000502:physiology; D006801:Humans; D008956:Models, Chemical; D008969:Molecular Sequence Data; D000090063:Proto-Oncogene Mas; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry; D016415:Sequence Alignment; D035561:Transcription Factor TFIIA / Q000737:chemistry / Q000502:physiology*; D014157:Transcription Factors / Q000737:chemistry
C119951:GTF2A1L protein, human; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D029701:Saccharomyces cerevisiae Proteins; C441519:TOA1 protein, S cerevisiae; D035561:Transcription Factor TFIIA; D014157:Transcription Factors; D010450:Endopeptidases; C480823:taspase1, human