Quaking Homolog, KH Domain RNA Binding (QKI)

QKI belongs to a family of RNA-binding proteins called STAR proteins for Signal Transduction and Activation of RNA. They have an HNRNPK homology (KH) domain embedded in a 200-amino acid region called the GSG domain. Other members of this family include SAM68 (KHDRBS1) and SF1.

The QKI gene is implicated as being important in schizophrenia, and QKI controls translation of many oligodendrocyte-related genes.The balance between the nuclear and cytoplasmic isoforms of Qk1 controlled the nuclear export of Mbp mRNAs and the cellular localization of the 17- and 21.5-kD Mbp isoforms. Overexpression of Qki-5 in cultured rodent oligodendrocytes recreated the Mbp defects observed in qk(v) mice, with retention of Mbp in the nucleus.