One of the major pre-mRNA-binding proteins. Binds tenaciously to poly(C) sequences. Likely to play a role in the nuclear metabolism of hnRNAs, particularly for pre-mRNAs that contain cytidine-rich sequences. Can also bind poly(C) single-stranded DNA. May play an important role in p53/TP53 response to DNA damage, acting at the level of both transcription activation and repression (By similarity). As part of a ribonucleoprotein complex, may negatively regulate the transcription of genes involved in neuronal differentiation (By similarity).