Serine/arginine-rich splicing factor 6 (SRSF6 or SRP55) belongs to a family of highly conserved RNA-binding splicing-factor proteins with one or two RNA-recognition motifs and a C-terminal arginine/serine-rich (RS) domain []. SRSF6 plays a role in constitutive splicing and modulates the selection of alternative splice sites [, , ]. SRSF6 is a proto-oncogene frequently overexpressed in human skin cancer [].
This entry represents the RNA recognition motif 1 (RRM1) of SRSF6, also termed pre-mRNA-splicing factor SRp55, which is an essential splicing regulatory serine/arginine (SR) protein that preferentially interacts with a number of purine-rich splicing enhancers (ESEs) to activate splicing of the ESE-containing exon []. It is the only protein from HeLa nuclear extract or purified SR proteins that specifically binds B element RNA after UV irradiation. SRSF6 may also recognize different types of RNA sites. For instance, it does not bind to the purine-rich sequence in the calcitonin-specific ESE, but binds to a region adjacent to the purine tract []. Moreover, cellular levels of SRSF6 may control tissue-specific alternative splicing of the calcitonin/ calcitonin gene-related peptide (CGRP) pre-mRNA []. SRSF6 contains two N-terminal RNA recognition motifs (RRMs), followed by a C-terminal SR domain rich in serine-arginine dipeptides.
