Serine/arginine-rich splicing factor 1 (Alternative-splicing factor 1) (ASF-1) (Splicing factor, arginine/serine-rich 1) (pre-mRNA-splicing factor SF2, P33 subunit)
1_MSGGG 6_ VIRGP 11_ AGNND 16_ CRIYV 21_ GNLPP 26_ DIRTK 31_ DIEDV 36_ FYKYG 41_ AIRDI 46_ DLKNR 51_ RGGPP 56_ FAFVE 61_ FEDPR 66_ DAEDA 71_ VYGRD 76_ GYDYD 81_ GYRLR 86_ VEFPR 91_ SGRGT 96_ GRGGG 101_ GGGGG 106_ GAPRG 111_ RYGPP 116_ SRRSE 121_ NRVVV 126_ SGLPP 131_ SGSWQ 136_ DLKDH 141_ MREAG 146_ DVCYA 151_ DVYRD 156_ GTGVV 161_ EFVRK 166_ EDMTY 171_ AVRKL 176_ DNTKF 181_ RSHEG 186_ ETAYI 191_ RVKVD 196_ GPRSP 201_ SYGRS 206_ RSRSR 211_ SRSRS 216_ RSRSN 221_ SRSRS 226_ YSPRR 231_ SRGSP 236_ RYSPR 241_HSRSR
1: Plays a role in preventing exon skipping, ensuring the accuracy of splicing and regulating alternative splicing. Interacts with other spliceosomal components, via the RS domains, to form a bridge between the 5'- and 3'-splice site binding components, U1 snRNP and U2AF. Can stimulate binding of U1 snRNP to a 5'-splice site-containing pre-mRNA. Binds to purine-rich RNA sequences, either the octamer, 5'-RGAAGAAC-3' (r=A or G) or the decamers, AGGACAGAGC/AGGACGAAGC. Binds preferentially to the 5'-CGAGGCG-3' motif in vitro. Three copies of the octamer constitute a powerful splicing enhancer in vitro, the ASF/SF2 splicing enhancer (ASE) which can specifically activate ASE-dependent splicing. Isoform ASF-2 and isoform ASF-3 act as splicing repressors. May function as export adapter involved in mRNA nuclear export through the TAP/NXF1 pathway