Polypyrimidine tract-binding protein 1 (PTB) (57 kDa RNA-binding protein PPTB-1) (Heterogeneous nuclear ribonucleoprotein I) (hnRNP I)
1_MDGIV 6_ PDIAV 11_ GTKRG 16_ SDELF 21_ STCVT 26_ NGPFI 31_ MSSNS 36_ ASAAN 41_ GNDSK 46_ KFKGD 51_ SRSAG 56_ VPSRV 61_ IHIRK 66_ LPIDV 71_ TEGEV 76_ ISLGL 81_ PFGKV 86_ TNLLM 91_ LKGKN 96_ QAFIE 101_ MNTEE 106_ AANTM 111_ VNYYT 116_ SVTPV 121_ LRGQP 126_ IYIQF 131_ SNHKE 136_ LKTDS 141_ SPNQA 146_ RAQAA 151_ LQAVN 156_ SVQSG 161_ NLALA 166_ ASAAA 171_ VDAGM 176_ AMAGQ 181_ SPVLR 186_ IIVEN 191_ LFYPV 196_ TLDVL 201_ HQIFS 206_ KFGTV 211_ LKIIT 216_ FTKNN 221_ QFQAL 226_ LQYAD 231_ PVSAQ 236_ HAKLS 241_ LDGQN 246_ IYNAC 251_ CTLRI 256_ DFSKL 261_ TSLNV 266_ KYNND 271_ KSRDY 276_ TRPDL 281_ PSGDS 286_ QPSLD 291_ QTMAA 296_ AFGLS 301_ VPNVH 306_ GALAP 311_ LAIPS 316_ AAAAA 321_ AAAGR 326_ IAIPG 331_ LAGAG 336_ NSVLL 341_ VSNLN 346_ PERVT 351_ PQSLF 356_ ILFGV 361_ YGDVQ 366_ RVKIL 371_ FNKKE 376_ NALVQ 381_ MADGN 386_ QAQLA 391_ MSHLN 396_ GHKLH 401_ GKPIR 406_ ITLSK 411_ HQNVQ 416_ LPREG 421_ QEDQG 426_ LTKDY 431_ GNSPL 436_ HRFKK 441_ PGSKN 446_ FQNIF 451_ PPSAT 456_ LHLSN 461_ IPPSV 466_ SEEDL 471_ KVLFS 476_ SNGGV 481_ VKGFK 486_ FFQKD 491_ RKMAL 496_ IQMGS 501_ VEEAV 506_ QALID 511_ LHNHD 516_ LGENH 521_ HLRVS 526_FSKST
1: Plays a role in pre-mRNA splicing and in the regulation of alternative splicing events. Activates exon skipping of its own pre-mRNA during muscle cell differentiation. Binds to the polypyrimidine tract of introns. May promote RNA looping when bound to two separate polypyrimidine tracts in the same pre-mRNA. May promote the binding of U2 snRNP to pre-mRNA. Cooperates with RAVER1 to modulate switching between mutually exclusive exons during maturation of the TPM1 pre-mRNA. Represses the splicing of MAPT/Tau exon 10 (PubMed:15009664). Binds to polypyrimidine-rich controlling element (PCE) of CFTR and promotes exon skipping of CFTR exon 9, thereby antagonizing TIA1 and its role in exon inclusion of CFTR exon 9 (PubMed:14966131). Plays a role in the splicing of pyruvate kinase PKM by binding repressively to a polypyrimidine tract flanking PKM exon 9, inhibiting exon 9 inclusion and resulting in exon 10 inclusion and production of the PKM M2 isoform (PubMed:20010808). In case of infection by picornaviruses, binds to the viral internal ribosome entry site (IRES) and stimulates the IRES-mediated translation (PubMed:21518806)