Izumo sperm-egg fusion protein 1 (Oocyte binding/fusion factor) (OBF) (Sperm-specific protein izumo)
1_MGPHF 6_ TLLCA 11_ ALAGC 16_ LLPAE 21_ GCVIC 26_ DPSVV 31_ LALKS 36_ LEKDY 41_ LPGHL 46_ DAKHH 51_ KAMME 56_ RVENA 61_ VKDFQ 66_ ELSLN 71_ EDAYM 76_ GVVDE 81_ ATLQK 86_ GSWSL 91_ LKDLK 96_ RITDS 101_ DVKGD 106_ LFVKE 111_ LFWML 116_ HLQKE 121_ TFATY 126_ VARFQ 131_ KEAYC 136_ PNKCG 141_ VMLQT 146_ LIWCK 151_ NCKKE 156_ VHACR 161_ KSYDC 166_ GERNV 171_ EVPQM 176_ EDMIL 181_ DCELN 186_ WHQAS 191_ EGLTD 196_ YSFYR 201_ VWGNN 206_ TETLV 211_ SKGKE 216_ ATLTK 221_ PMVGP 226_ EDAGS 231_ YRCEL 236_ GSVNS 241_ SPATI 246_ INFHV 251_ TVLPK 256_ MIKEE 261_ KPSPN 266_ IVTPG 271_ EATTE 276_ SSISL 281_ QPLQP 286_ EKMLA 291_ SRLLG 296_ LLICG 301_ SLALI 306_ TGLTF 311_ AIFRR 316_ RKVID 321_ FIKSS 326_ LFGLG 331_ SGAAE 336_ QTQVP 341_KEKAT
1: Essential sperm cell-surface protein required for fertilization by acting as a ligand for IZUMO1R/JUNO receptor on egg. The IZUMO1:IZUMO1R/JUNO interaction is a necessary adhesion event between sperm and egg that is required for fertilization but is not sufficient for cell fusion. The ligand-receptor interaction probably does not act as a membrane 'fusogen'. Acts a ligand for the human-specific oolemma epitope FCRL3/MAIA during fertilization (PubMed:36070373). FCRL3/MAIA replaces IZUMO1R/JUNO as IZUMO1 receptor after sperm-egg adhesion, which permits species-specific gamete fusion (PubMed:36070373). Plays a critical role in sperm-oolemma binding prior to plasma membrane fusion. Can mediate cell-cell fusion in cultured mammalian cells independently of its binding to IZUMO1R/JUNO (By similarity)