Numb Homolog (NUMB)

NUMB contains a predicted phosphotyrosine-binding domain and shares 63% identity with Drosophila Numb. The C-terminal half shows little similarity with Drosophila Numb and includes a proline-rich segment with potential SH3-binding sites. Immunofluorescence experiments revealed that mouse Numb is asymmetrically localized to the apical membrane of dividing ventricular neural progenitors during mouse cortical neurogenesis. However, unlike Drosophila Numb, there was no correlation between cleavage planes and mouse Numb localization at the apical cell membrane in anaphase ventricular cells.NUMB contains an N-terminal phosphotyrosine-binding (PTB) domain, SH3-binding sites, and a C-terminal asn-pro-phe (NPF) motif. NUMB shares 57% amino acid identity with NUMBL.