Protein transport protein Sec61 subunit alpha isoform 1 (Sec61 alpha-1)
1_MAIKF 6_ LEVIK 11_ PFCVI 16_ LPEIQ 21_ KPERK 26_ IQFKE 31_ KVLWT 36_ AITLF 41_ IFLVC 46_ CQIPL 51_ FGIMS 56_ SDSAD 61_ PFYWM 66_ RVILA 71_ SNRGT 76_ LMELG 81_ ISPIV 86_ TSGLI 91_ MQLLA 96_ GAKII 101_ EVGDT 106_ PKDRA 111_ LFNGA 116_ QKLFG 121_ MIITI 126_ GQSIV 131_ YVMTG 136_ MYGDP 141_ SEMGA 146_ GICLL 151_ ITIQL 156_ FVAGL 161_ IVLLL 166_ DELLQ 171_ KGYGL 176_ GSGIS 181_ LFIAT 186_ NICET 191_ IVWKA 196_ FSPTT 201_ VNTGR 206_ GMEFE 211_ GAIIA 216_ LFHLL 221_ ATRTD 226_ KVRAL 231_ REAFY 236_ RQNLP 241_ NLMNL 246_ IATIF 251_ VFAVV 256_ IYFQG 261_ FRVDL 266_ PIKSA 271_ RYRGQ 276_ YNTYP 281_ IKLFY 286_ TSNIP 291_ IILQS 296_ ALVSN 301_ LYVIS 306_ QMLSA 311_ RFSGN 316_ LLVSL 321_ LGTWS 326_ DTSSG 331_ GPARA 336_ YPVGG 341_ LCYYL 346_ SPPES 351_ FGSVL 356_ EDPVH 361_ AVVYI 366_ VFMLG 371_ SCAFF 376_ SKTWI 381_ EVSGS 386_ SAKDV 391_ AKQLK 396_ EQQMV 401_ MRGHR 406_ ETSMV 411_ HELNR 416_ YIPTA 421_ AAFGG 426_ LCIGA 431_ LSVLA 436_ DFLGA 441_ IGSGT 446_ GILLA 451_ VTIIY 456_ QYFEI 461_ FVKEQ 466_ SEVGS 471_MGALL
1: Component of SEC61 channel-forming translocon complex that mediates transport of signal peptide-containing precursor polypeptides across the endoplasmic reticulum (ER) (PubMed:12475939, PubMed:22375059, PubMed:28782633, PubMed:29719251, PubMed:32814900). Forms a ribosome receptor and a gated pore in the ER membrane, both functions required for cotranslational translocation of nascent polypeptides (PubMed:22375059, PubMed:28782633, PubMed:29719251). May cooperate with auxiliary protein SEC62, SEC63 and HSPA5/BiP to enable post-translational transport of small presecretory proteins (PubMed:22375059, PubMed:29719251). The SEC61 channel is also involved in ER membrane insertion of transmembrane proteins: it mediates membrane insertion of the first few transmembrane segments of proteins, while insertion of subsequent transmembrane regions of multi-pass membrane proteins is mediated by the multi-pass translocon (MPT) complex (PubMed:32820719, PubMed:36261522). The SEC61 channel cooperates with the translocating protein TRAM1 to import nascent proteins into the ER (PubMed:8616892). Controls the passive efflux of calcium ions from the ER lumen to the cytosol through SEC61 channel, contributing to the maintenance of cellular calcium homeostasis (PubMed:28782633). Plays a critical role in nephrogenesis, specifically at pronephros stage (By similarity)