Sodium/myo-inositol cotransporter (Na(+)/myo-inositol cotransporter) (Sodium/myo-inositol transporter 1) (SMIT1) (Solute carrier family 5 member 3)
1_MRAVL 6_ DTADI 11_ AIVAL 16_ YFILV 21_ MCIGF 26_ FAMWK 31_ SNRST 36_ VSGYF 41_ LAGRS 46_ MTWVA 51_ IGASL 56_ FVSNI 61_ GSEHF 66_ IGLAG 71_ SGAAS 76_ GFAVG 81_ AWEFN 86_ ALLLL 91_ QLLGW 96_ VFIPI 101_ YIRSG 106_ VYTMP 111_ EYLSK 116_ RFGGH 121_ RIQVY 126_ FAALS 131_ LILYI 136_ FTKLS 141_ VDLYS 146_ GALFI 151_ QESLG 156_ WNLYV 161_ SVILL 166_ IGMTA 171_ LLTVT 176_ GGLVA 181_ VIYTD 186_ TLQAL 191_ LMIIG 196_ ALTLM 201_ IISIM 206_ EIGGF 211_ EEVKR 216_ RYMLA 221_ SPDVT 226_ SILLT 231_ YNLSN 236_ TNSCN 241_ VSPKK 246_ EALKM 251_ LRNPT 256_ DEDVP 261_ WPGFI 266_ LGQTP 271_ ASVWY 276_ WCADQ 281_ VIVQR 286_ VLAAK 291_ NIAHA 296_ KGSTL 301_ MAGFL 306_ KLLPM 311_ FIIVV 316_ PGMIS 321_ RILFT 326_ DDIAC 331_ INPEH 336_ CMLVC 341_ GSRAG 346_ CSNIA 351_ YPRLV 356_ MKLVP 361_ VGLRG 366_ LMMAV 371_ MIAAL 376_ MSDLD 381_ SIFNS 386_ ASTIF 391_ TLDVY 396_ KLIRK 401_ SASSR 406_ ELMIV 411_ GRIFV 416_ AFMVV 421_ ISIAW 426_ VPIIV 431_ EMQGG 436_ QMYLY 441_ IQEVA 446_ DYLTP 451_ PVAAL 456_ FLLAI 461_ FWKRC 466_ NEQGA 471_ FYGGM 476_ AGFVL 481_ GAVRL 486_ ILAFA 491_ YRAPE 496_ CDQPD 501_ NRPGF 506_ IKDIH 511_ YMYVA 516_ TGLFW 521_ VTGLI 526_ TVIVS 531_ LLTPP 536_ PTKEQ 541_ IRTTT 546_ FWSKK 551_ NLVVK 556_ ENCSP 561_ KEEPY 566_ QMQEK 571_ SILRC 576_ SENNE 581_ TINHI 586_ IPNGK 591_ SEDSI 596_ KGLQP 601_ EDVNL 606_ LVTCR 611_ EEGNP 616_ VASLG 621_ HSEAE 626_ TPVDA 631_ YSNGQ 636_ AALMG 641_ EKERK 646_ KETDD 651_ GGRYW 656_ KFIDW 661_ FCGFK 666_ SKSLS 671_ KRSLR 676_ DLMEE 681_ EAVCL 686_ QMLEE 691_ TRQVK 696_ VILNI 701_ GLFAV 706_ CSLGI 711_FMFVY
1: Electrogenic Na(+)-coupled sugar symporter that actively transports myo-inositol and its stereoisomer scyllo-inositol across the plasma membrane, with a Na(+) to sugar coupling ratio of 2:1 (By similarity). Maintains myo-inositol concentration gradient that defines cell volume and fluid balance during osmotic stress, in particular in the fetoplacental unit and central nervous system (By similarity). Forms coregulatory complexes with voltage-gated K(+) ion channels, allosterically altering ion selectivity, voltage dependence and gating kinetics of the channel. In turn, K(+) efflux through the channel forms a local electrical gradient that modulates electrogenic Na(+)-coupled myo-inositol influx through the transporter (PubMed:24595108, PubMed:28793216). Associates with KCNQ1-KCNE2 channel in the apical membrane of choroid plexus epithelium and regulates the myo-inositol gradient between blood and cerebrospinal fluid with an impact on neuron excitability (By similarity) (PubMed:24595108). Associates with KCNQ2-KCNQ3 channel altering ion selectivity, increasing Na(+) and Cs(+) permeation relative to K(+) permeation (PubMed:28793216). Provides myo-inositol precursor for biosynthesis of phosphoinositides such as PI(4,5)P2, thus indirectly affecting the activity of phosphoinositide-dependent ion channels and Ca(2+) signaling upon osmotic stress (PubMed:27217553)