RNA U small nuclear RNA export adapter protein (phosphorylated adapter RNA export protein, RNUXA, PHAX)

Function: 1) phosphoprotein adapter involved in the XPO1-mediated U snRNA export from the nucleus - components of the nuclear export include: - cap binding complex snRNA GTP-bound GTPase Ran export receptor XPO1 2) phosphorylation in the nucleus is required for U snRNA export complex assembly 3) dephosphorylation in the cytoplasm causes export complex disassembly 4) recycled back to the nucleus via the importin alpha/beta heterodimeric import receptor 5) directionality of nuclear export conferred by an asymmetric distribution of GTP- & GDP-bound forms of Ran between the cytoplasm & nucleu 6) compartmentalized phosphorylation cycle may also contribute to the directionality of export 7) binds strongly to m7G-capped U1 & U5 small nuclear RNAs (sequence-nonspecific & phosphorylation- independent 8) biogenesis of U3 small nucleolar RNA (snoRNA) 9) U3 snoRNA transport from nucleoplasm to Cajal bodies 10) binds strongly to m7G-capped U3, U8 & U13 precursor snoRNAs & weakly to trimethylated [TMG]-capped U3, U8 & U13 snoRNAs 11) binds to telomerase RNA 12) component of U snRNA export complex 13) interacts with NCBP1 14 forms complex with snoRNA Compartment: - nucleus, cytoplasm, nucleoplasm, Cajal bodies - shuttles between the nucleus & the cytoplasm - shuttles between the nucleoplasm & Cajal bodies

General

phosphoprotein RNA-binding protein

Properties

SIZE: MW = 44 kD entity length = 394 aa COMPARTMENT: cytoplasm cell nucleus MOTIF: nuclear translocation signal {81-84} nuclear export signal {130-139} nuclear translocation signal {198-201} binding site SITE: 228-328 FOR-BINDING-OF: ribonucleic acid binding site SITE: 279-287 FOR-BINDING-OF: ribonucleic acid

Database Correlations

OMIM 604924 UniProt Q9H814

References

UniProt :accession Q9H814