Functional interaction of general transcription initiation factor TFIIE with general chromatin factor SPT16/CDC68.
BACKGROUND
Transcriptional initiation of class II genes is one of the major targets for the regulation of gene expression and is carried out by RNA polymerase II and many auxiliary factors, which include general transcription initiation factors (GTFs). TFIIE, one of the GTFs, functions at the later stage of transcription initiation. As recent studies indicated the possibility that TFIIE may have a role in chromatin transcriptional regulation, we isolated TFIIE-interacting factors which have chromatin-related functions.


RESULTS
Using the yeast two-hybrid screening system, we isolated the C-terminal part of the human homologue of Saccharomyces cerevisiae (y) Spt16p/Cdc68p, a general chromatin factor. The C-terminal part of human SPT16/CDC68 directly interacts with TFIIE, and ySpt16p/Cdc68p also interacts with yTFIIE (Tfa1p/Tfa2p), thus indicating the existence of an evolutionarily conserved interaction between TFIIE and SPT16/CDC68. Functional interaction of yTFIIE and ySpt16p/Cdc68p was examined using a conditional yTFIIE-alpha mutant strain. Over-expression of ySpt16p/Cdc68p suppressed the phenotype of cold sensitivity of the yTFIIE-alpha-cs mutant strain, and in vitro binding assays revealed that yTFIIE-alpha-cs mutant protein showed diminished binding affinity to ySpt16p/Cdc68p.


CONCLUSIONS
These observations indicate that general transcription initiation factor TFIIE functionally interacts with general chromatin factor SPT16/CDC68, a finding which provides new insight into the involvement of TFIIE in chromatin transcription. This may well lead to a breakthrough in relationships between the transcription initiation process and structural changes in chromatin.
Kang
S W
SW
Laboratory of Developmental Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
Kuzuhara
T
T
Horikoshi
M
M
D000595:Amino Acid Sequence; D015152:Blotting, Northern; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D019143:Evolution, Molecular; D005260:Female; D005656:Fungal Proteins / Q000378:metabolism; D015870:Gene Expression; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D019473:Transcription Factors, TFII; D035602:Transcriptional Elongation Factors; D020798:Two-Hybrid System Techniques
D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D005656:Fungal Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C071238:SPT16 protein, S cerevisiae; C489489:SUPT16H protein, human; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D035602:Transcriptional Elongation Factors; C066644:transcription factor TFIIE; D005982:Glutathione Transferase