FIGURE 1.

The human QKI gene, major isoforms and protein products. The QUA1 dimerization domain, KH RNA binding domain and QUA2 domains are present in all isoforms and are called the STAR domain. Alternative splicing and alternative polyadenylation events generate the major splice isoforms of QKI, while an N‐terminal truncation in Exon 6 has also been detected. Post‐translational phosphorylation can occur in SH3 and tyrosine clusters. QKI‐5 has a distinct 3'UTR and has a NLS in its C‐terminal region restricting its activity to the nucleus. NLS, nuclear localization signal; QKI, RNA‐binding protein Quaking; SRC, SRC homology 3 domain (SH3); STAR, signal transduction and activation of RNA