Plays a role in constitutive splicing and can modulate the selection of alternative splice sites. Represses the splicing of MAPT/Tau exon 10. Interacts with KHDRBS3 (By similarity). Interacts with HABP4 (PubMed:19523114). Interacts with NOL3/ARC/NOP30 (PubMed:10196175). Interacts with NSEP1/YB-1/YB1 (PubMed:12604611). Interacts with SAFB/SAFB1 (PubMed:9671816, PubMed:11694584). Interacts with SRSF6/SFRS6 (PubMed:15695522). Interacts with TRA2B/SFRS10 (PubMed:11875052, PubMed:15695522). Interacts with C1QBP (PubMed:10022843). May also interact with DUSP11/PIR1(PubMed:11694584). Cellular stresses such as heat shock may induce localization to discrete nuclear bodies termed SAM68 nuclear bodies (SNBs), HAP bodies, or stress bodies. Numerous splicing factors including SRSF1/SFRS1/SF2, SRSF7/SFRS7, SAFB and KHDRBS1/SAM68 accumulate at these structures, which may participate in the post-transcriptional regulation of mRNAs in stressed cells. Expressed at high levels in the heart, kidney, pancreas and placenta, and at lower levels in the brain, liver, lung and skeletal muscle. Extensively phosphorylated on serine residues in the RS domain. Belongs to the splicing factor SR family.