Phosphorylated adaptor for RNA export (PHAX)

Phosphorylated adaptor for RNA export (PHAX) is an RNA-binding nuclear transport protein essential for the export of small nuclear RNAs (such as U snRNA) from the nucleus to the cytoplasm in metazoans. PHAX acts as a bridge between the cap binding complex (CBC)-bound snRNA and the export receptor XPO1 (also known as CRM1), and its phosphorylation state controls assembly and disassembly of the export complex: phosphorylation in the nucleus is required for export complex assembly and export, while dephosphorylation in the cytoplasm leads to complex disassembly and recycling of PHAX. PHAX is also involved in the intranuclear trafficking and biogenesis of small nucleolar RNA (snoRNA), binding both precursor and mature forms in a cap-dependent manner. Mutations in PHAX are associated with developmental brain disorders, but it is not considered a direct therapeutic drug target.

Other names

PHAXRNUXARNA U, small nuclear RNA export adaptor (phosphorylation regulated)RNA U small nuclear RNA export adapter proteinPhosphorylated adapter RNA export proteinFLJ13193