Polyadenylate-binding protein 2 (PABP-2) (Poly(A)-binding protein 2) (Nuclear poly(A)-binding protein 1) (Poly(A)-binding protein II) (PABII) (Polyadenylate-binding nuclear protein 1)
1_MAAAA 6_ AAAAA 11_ AGAAG 16_ GRGSG 21_ PGRRR 26_ HLVPG 31_ AGGEA 36_ GEGAP 41_ GGAGD 46_ YGNGL 51_ ESEEL 56_ EPEEL 61_ LLEPE 66_ PEPEP 71_ EEEPP 76_ RPRAP 81_ PGAPG 86_ PGPGS 91_ GAPGS 96_ QEEEE 101_ EPGLV 106_ EGDPG 111_ DGAIE 116_ DPELE 121_ AIKAR 126_ VREME 131_ EEAEK 136_ LKELQ 141_ NEVEK 146_ QMNMS 151_ PPPGN 156_ AGPVI 161_ MSIEE 166_ KMEAD 171_ ARSIY 176_ VGNVD 181_ YGATA 186_ EELEA 191_ HFHGC 196_ GSVNR 201_ VTILC 206_ DKFSG 211_ HPKGF 216_ AYIEF 221_ SDKES 226_ VRTSL 231_ ALDES 236_ LFRGR 241_ QIKVI 246_ PKRTN 251_ RPGIS 256_ TTDRG 261_ FPRAR 266_ YRART 271_ TNYNS 276_ SRSRF 281_ YSGFN 286_ SRPRG 291_ RVYRG 296_ RARAT 301_SWYSP
1: Involved in the 3'-end formation of mRNA precursors (pre-mRNA) by the addition of a poly(A) tail of 200-250 nt to the upstream cleavage product (By similarity). Stimulates poly(A) polymerase (PAPOLA) conferring processivity on the poly(A) tail elongation reaction and also controls the poly(A) tail length (By similarity). Increases the affinity of poly(A) polymerase for RNA (By similarity). Is also present at various stages of mRNA metabolism including nucleocytoplasmic trafficking and nonsense-mediated decay (NMD) of mRNA. Cooperates with SKIP to synergistically activate E-box-mediated transcription through MYOD1 and may regulate the expression of muscle-specific genes (PubMed:11371506). Binds to poly(A) and to poly(G) with high affinity (By similarity). May protect the poly(A) tail from degradation (By similarity). Subunit of the trimeric poly(A) tail exosome targeting (PAXT) complex, a complex that directs a subset of long and polyadenylated poly(A) RNAs for exosomal degradation. The RNA exosome is fundamental for the degradation of RNA in eukaryotic nuclei. Substrate targeting is facilitated by its cofactor MTREX, which links to RNA-binding protein adapters (PubMed:27871484)