Dose-dependent regulation of target gene expression and cell proliferation by c-Myc levels

Landes Bioscience Transcription, 2013, DOI 10.4161/trns.25907, Volume 4. Issue 4, 192 - 197 published on 31.07.2013
Landes Bioscience Transcription, online article
The proto-oncogene c-myc encodes a basic helix-loop-helix leucine zipper transcription factor (c-Myc). c-Myc plays a crucial role in cell growth and proliferation. Here, we examined how expression of c-Myc target genes and cell proliferation depend on variation of c-Myc protein levels. We show that proliferation rates, the number of cells in S-phase, and cell size increased in a dose-dependent manner in response to increasing c-Myc levels. Likewise, the mRNA levels of c-Myc responsive genes steadily increased with rising c-Myc levels. Strikingly, steady-state mRNA levels of c-Myc target genes did not saturate even at highest c-Myc concentrations. These characteristics predestine c-Myc levels as a cellular rheostat for the control and fine-tuning of cell proliferation and growth rates.

TU München
Helmholtz München
MPI of Neurobiology
MPI of Biochemistry