RNA binding protein that regulates the expression of target mRNAs at the translation level. Regulates expression of the NOTCH1 antagonist NUMB. Binds RNA containing the sequence 5'-GUUAGUUAGUUAGUU-3' and other sequences containing the pattern 5'-[GA]U(1-3)AGU-3'. May play a role in the proliferation and maintenance of stem cells in the central nervous system. Expressed in neural stem and progenitor cells (at protein level) (PubMed:16554442). Detected in olfactory bulb, brain stem, small intestine, and at low levels in brain cortex, hippocampus and ovary (PubMed:8660864). Detected in neural progenitor cells, including neural stem cells (PubMed:8660864). Highly expressed in embryonic brain at day 12. Expressed at intermediate levels during the rest of embryonic development and in newborns up to day 3. After this expression decreases and stabilizes at low levels of expression around day 13. The first RNA recognition motif binds more strongly to RNA compared to the second one. Belongs to the Musashi family.