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.