Musashi: a translational regulator of cell fate.

Transcription is thought to have a major role in the regulation of cell fate; the importance of translational regulation in this process has been less certain. Recent findings demonstrate that translational regulation contributes to cell-fate specification. The evolutionarily conserved, neural RNA-binding protein Musashi, for example, controls neural cell fate. The protein functions in maintenance of the stem-cell state, differentiation, and tumorigenesis by repressing translation of particular mRNAs. In mammals it might play an important role in activating Notch signalling by repressing translation of the Notch inhibitor m-Numb.