Polypyrimidine Tract Binding Protein 2 (PTBP2)

PTBP2 is a component of an RNA-binding complex that binds an intronic cluster of pre-mRNA regulatory elements called the downstream control sequence (DCS) and controls the pattern of exon splicing.

The deduced 531-amino acid protein has a calculated molecular mass of 57.5 kD. PTBP2 contains an N-terminal bipartite nuclear localization signal and 4 RNA recognition motif domains similar to those of PTBP1 . PTBP2 and PTBP1 share about 74% amino acid identity. Northern blot analysis detected a 3.4-kb transcript expressed predominantly in brain. Robust expression was also detected in neural cells and in a neuroblastoma cell line, but only weak expression was detected in nonneural cell lines. Western blot analysis detected purified PTBP2 at an apparent molecular mass of 60 kD.