Nuclear cap-binding protein subunit 2 (NCBP2)

Component of the cap-binding complex (CBC), which binds co-transcriptionally to the 5' cap of pre-mRNAs and is involved in a variety of processes like pre-mRNA splicing, translation regulation, nonsense-mediated mRNA decay, RNA-mediated gene silencing (RNAi) by microRNAs (miRNAs) and mRNA export. The CBC complex is also involved in mediating U snRNA and intronless mRNAs export from the nucleus.

The CBC complex is vital for a pioneer round of mRNA translation, before steady state translation when the CBC complex is replaced by cytoplasmic cap-binding protein eIF4E. The pioneer round of mRNA translation mediated by the CBC complex plays a central role in nonsense-mediated mRNA decay (NMD), NMD just taking place in mRNAs bound to the CBC complicated, but not on eIF4E-bound mRNAs.