Identification of a novel partner of RNA polymerase II subunit 11, Che-1, which interacts with and affects the growth suppression function of Rb.
Fanciulli M., Bruno T., Di Padova M., De Angelis R., Iezzi S., Iacobini C., Floridi A., Passananti C.
hRPB11 is a core subunit of RNA polymerase II (pol II) specifically down-regulated on doxorubicin (dox) treatment. Levels of this protein profoundly affect cell differentiation, cell proliferation, and tumorigenicity in vivo. Here we describe Che-1, a novel human protein that interacts with hRPB11. Che-1 possesses a domain of high homology with Escherichia coli RNA polymerase final sigma-factor 70 and SV40 large T antigen. In addition, we report that Che-1 interacts with the retinoblastoma susceptibility gene (Rb) by two distinct domains. Functionally, we demonstrate that Che-1 represses the growth suppression function of Rb, counteracting the inhibitory action of Rb on the trans-activation function of E2F1. These results identify a novel protein that binds Rb and the core of pol II, and suggest that Che-1 may be part of transcription regulatory complex.
FASEB J. 14:904-912(2000) [ PubMed | SRS | CiteXplore ]
