A critical role for cyclin C in promotion of the hematopoietic cell cycle by cooperation with c-Myc

Mol Cell Biol. 1998 Jun;18(6):3445-54. doi: 10.1128/MCB.18.6.3445.


Cyclin C, a putative G1 cyclin, was originally isolated through its ability to complement a Saccharomyces cerevisiae strain lacking the G1 cyclin gene CLN1-3. Unlike cyclins D1 and E, the other two G1 cyclins obtained by the same approach and subsequently shown to play important roles during the G1/S transition, there is thus far no evidence to support the hypothesis that cyclin C is indeed critical for the promotion of cell cycle progression. In BAF-B03 cells, an interleukin 3 (IL-3)-dependent murine pro-B-cell line, cyclin C gene mRNA was induced at the G1/S phase upon IL-3 stimulation and reached a maximal level in the S phase. Enforced expression of exogenous cyclin C in this cell line failed to alter its growth properties. In the present study, we examined whether cyclin C is capable of cooperating with the cytokine-responsive immediate-early gene products c-Myc and c-Fos in the promotion of cell proliferation. We found that cyclin C is able to cooperate functionally with c-Myc, but not c-Fos, to induce both BAF-B03 cell proliferation in a cytokine-independent fashion and the formation of cell clusters. Furthermore, cyclin C was primarily responsible for the induction of cdc2 gene expression. Our data define a novel role for cyclin C in the regulation of both the G1/S and G2/M phases of the cell cycle, and this effect appears to be independent of the activity of CDK8 in the control of transcription.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / cytology
  • CDC2 Protein Kinase / biosynthesis
  • CDC2 Protein Kinase / genetics
  • Cell Cycle / physiology*
  • Cells, Cultured
  • Cyclin C
  • Cyclin D3
  • Cyclin E / metabolism
  • Cyclin-Dependent Kinases*
  • Cyclins / biosynthesis
  • Cyclins / genetics
  • Cyclins / metabolism
  • Cyclins / physiology*
  • Hematopoietic Stem Cells / cytology*
  • Interleukin-3 / metabolism
  • Interphase
  • Mice
  • Mitosis
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins c-fos / biosynthesis
  • Proto-Oncogene Proteins c-fos / genetics
  • Proto-Oncogene Proteins c-myc / physiology*
  • RNA, Messenger / metabolism
  • Transcription, Genetic


  • CCNC protein, human
  • CCND3 protein, human
  • Ccnc protein, mouse
  • Ccnd3 protein, mouse
  • Cyclin C
  • Cyclin D3
  • Cyclin E
  • Cyclins
  • Interleukin-3
  • Proto-Oncogene Proteins c-fos
  • Proto-Oncogene Proteins c-myc
  • RNA, Messenger
  • Protein Serine-Threonine Kinases
  • CDC2 Protein Kinase
  • Cyclin-Dependent Kinases