Previous Article | Next Article ![]()
Mol. Cell. Biol., 11 1996, 6457-6467, Vol 16, No. 11
H Hirai and CJ Sherr
The cyclin D-dependent kinases CDK4 and CDK6 trigger phosphorylation of the
retinoblastoma protein (RB) late in G1 phase, helping to cancel its
growth-suppressive function and thereby facilitating S-phase entry.
Although specific inhibition of cyclin D-dependent kinase activity in vivo
can prevent cells from entering S phase, it does not affect S- phase entry
in cells lacking functional RB, implying that RB may be the only substrate
of CDK4 and CDK6 whose phosphorylation is necessary for G1 exit. Using a
yeast two-hybrid interactive screen, we have now isolated a novel cyclin
D-interacting myb-like protein (designated DMP1), which binds specifically
to the nonamer DNA consensus sequences CCCG(G/T)ATGT to activate
transcription. A subset of these DMP1 recognition sequences containing a
GGA trinucleotide core can also function as Ets-responsive elements. DMP1
mRNA and protein are ubiquitously expressed throughout the cell cycle in
mouse tissues and in representative cell lines. DMP1 binds to D-type
cyclins directly in vitro and when coexpressed in insect Sf9 cells. In both
settings, it can be phosphorylated by cyclin D-dependent kinases,
suggesting that its transcriptional activity may normally be regulated
through such mechanisms. These results raise the possibility that cyclin
D-dependent kinases regulate gene expression in an RB independent manner,
thereby serving to link other genetic programs to the cell cycle clock.
Copyright © 1996, American Society for Microbiology
Interaction of D-type cyclins with a novel myb-like transcription factor, DMP1
Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»