Fig. 1.

Domain organisation of Sam68 and T-STAR. (A) Sam68 and T-STAR contain a STAR domain responsible for RNA binding that is composed of a central KH domain flanked by QUA1 and QUA2 regions. In addition, these proteins contain various motifs necessary for the cellular function of the protein. The nuclear localisation signal (NLS) allows the proteins to shuttle between the cytoplasm and the nucleus. The proline-rich (PRO) and tyrosine-rich regions (YY) are necessary for tyrosine phosphorylation of these proteins and the arginine–glycine rich regions (RG) are target sites for arginine methylation. (B) Sequence alignment of Sam68 and T-STAR STAR domains. The amino acids of these two proteins in this region are 69% identical (red), 16% highly homologous (green) and 5% homologous (blue). The alignment was performed using CLUSTALW. The KH domain is highlighted in yellow.