Nuclear cap-binding protein subunit 2 (NCBP2)

Nuclear cap-binding protein subunit 2 (NCBP2, also known as CBP20) is a small, highly conserved subunit of the nuclear cap-binding complex (CBC), a heterodimeric protein complex in the nucleus of eukaryotic cells composed of NCBP1 (CBP80) and NCBP2 (CBP20)[1][2][3]. NCBP2 contains a classical RNA-binding domain and is directly responsible for binding the 7-methylguanosine cap structure found at the 5' end of nascent RNA polymerase II transcripts, such as pre-mRNAs and some small nuclear RNAs[3][5]. By recognizing this cap, CBC (with NCBP2 as the cap-interacting subunit) coordinates multiple steps of RNA metabolism including splicing, 3'-end processing, translation regulation, nuclear export of mRNA, and triggering nonsense-mediated decay, ensuring that mRNA precursors are accurately processed and protected from degradation[1][3][5]. NCBP2 is not classified as a therapeutic drug target nor a receptor, enzyme, or transporter; rather, it is a component of an RNA-binding complex essential for basic gene expression processes. Variants in NCBP2 have been associated with rare genetic diseases such as Seckel syndrome and spinal muscular atrophy type I[5]. There are currently no drugs specifically targeting NCBP2, and it is not used as a clinical biomarker or associated with notable therapeutic safety concerns.

Other names

CBP20PIG55NIP1Cbc220 kDa nuclear cap-binding proteincell proliferation-inducing gene 55 proteinNCBP 20 kDa subunitNCBP-interacting protein 1CBC2