MCM proteins are associated with RNA polymerase II holoenzyme.
MCMs are a family of proteins related to ATP-dependent helicases that bind to origin recognition complexes and are required for initiation of DNA replication. We report that antibodies against MCM2(BM28) specifically inhibited transcription by RNA polymerase II (Pol II) in microinjected Xenopus oocytes. Consistent with this observation, MCM2 and other MCMs copurified with Pol II and general transcription factors (GTFs) in high-molecular-weight holoenzyme complexes isolated from Xenopus oocytes and HeLa cells. Pol II and GTFs also copurified with MCMs isolated by anti-MCM3 immunoaffinity chromatography. MCMs were specifically displaced from the holoenzyme complex by antibody against the C-terminal domain (CTD) of Pol II. In addition, MCMs bound to a CTD affinity column, suggesting that their association with holoenzyme depends in part on this domain of Pol II. These results suggest a new function for MCM proteins as components of the Pol II transcriptional apparatus.
Yankulov
K
K
Department of Molecular Biology and Genetics, University of Guelph, Guelph, Ontario N1G 2W1, Canada. yankulov@uoguelph.ca
Todorov
I
I
Romanowski
P
P
Licatalosi
D
D
Cilli
K
K
McCracken
S
S
Laskey
R
R
Bentley
D L
DL
D000818:Animals; D000906:Antibodies; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D002846:Chromatography, Affinity; D004257:DNA Polymerase II / Q000302:isolation & purification / Q000378:metabolism*; D004285:Dogs; D005260:Female; D006367:HeLa Cells; D020035:Holoenzymes / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D064111:Minichromosome Maintenance Complex Component 2; D009687:Nuclear Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism; D020365:RNA Helicases / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism; D014158:Transcription, Genetic; D014982:Xenopus laevis
D000906:Antibodies; D018797:Cell Cycle Proteins; D020035:Holoenzymes; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D014157:Transcription Factors; D004257:DNA Polymerase II; C084859:MCM2 protein, human; D064111:Minichromosome Maintenance Complex Component 2; D020365:RNA Helicases