Arginine/Serine Rich Coiled Coil Protein 1 (RSRC1)

SRRP53 interacted with several components of the splicing machinery, including LUC7, HCC1 (RNPC2), SF2/ASF (SFRS1), SRP40 (SFRS5), and U2AF35 (U2AF1). The C-terminal domain of SRRP53 was involved in the interaction with HCC1, and the N-terminal RS domain of SRRP53 mediated the interactions with the other splicing proteins. Protein pull-down and immunoprecipitation analyses confirmed the interactions of SRRP53 with SF2/ASF, HCC1, and LUC7. HeLa cells immunodepleted of SRRP53 were unable to complete the splicing of test substrates, and addition of recombinant SRRP53 restored splicing activity. SRRP53 also altered splice-site selection in a concentration-dependent manner and appeared to activate a weak 3-prime splice site.