Physical association of the APIS complex and general transcription factors.
It has recently been demonstrated that a fragment of the proteasome, called the APIS complex, plays an important role in RNA polymerase II-mediated transcription. Here, it is shown that the APIS complex is physically associated with many general transcription factors, including components of yeast FACT (Cdc68/Pob3), TFIID, TFIIH, and the RNA polymerase II holoenzyme. Depletion of this APIS transcription factor complex from a yeast whole cell extract resulted in reduced transcription, indicating that it is functionally relevant. The APIS/transcription factor complex does not include detectable levels of the 20S proteolytic sub-unit of the proteasome. Furthermore, immunopurified 26S proteasome contains little or no transcription factors, suggesting that transcription factors and the 20S bind competitively to the APIS complex. These data add to the growing body of evidence that the APIS complex has a role in transcription, independent of its role in proteolysis and, furthermore, argues that it functions in association with the general transcription complex.
Departments of Internal Medicine and Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8573, USA.
Liping
L
Sun
Stephen Albert
SA
Johnston
Thomas
T
Kodadek
D000251:Adenosine Triphosphatases / Q000378:metabolism; D019921:Biotinylation; D002352:Carrier Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000737:chemistry*; D000939:Epitopes / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D017930:Genes, Reporter; D005982:Glutathione Transferase / Q000378:metabolism; D009097:Multienzyme Complexes / Q000737:chemistry*; D028061:Phosphate Transport Proteins / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000378:metabolism; D019473:Transcription Factors, TFII / Q000378:metabolism; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors; D025801:Ubiquitin / Q000378:metabolism
D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D000939:Epitopes; D005656:Fungal Proteins; D009097:Multienzyme Complexes; C106768:POB3 protein, S cerevisiae; D028061:Phosphate Transport Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C071238:SPT16 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C490039:TAF6 protein, S cerevisiae; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D035602:Transcriptional Elongation Factors; D025801:Ubiquitin; D051758:Transcription Factor TFIIH; C055831:phosphate permease; D005982:Glutathione Transferase; D012319:RNA Polymerase II; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D000251:Adenosine Triphosphatases; C069670:RPT6 protein, S cerevisiae