Intermediate conductance calcium-activated potassium channel protein 4 (SK4) (SKCa 4) (SKCa4) (IKCa1) (IK1) (KCa3.1) (KCa4) (Putative Gardos channel)
1_MGGDL 6_ VLGLG 11_ ALRRR 16_ KRLLE 21_ QEKSL 26_ AGWAL 31_ VLAGT 36_ GIGLM 41_ VLHAE 46_ MLWFG 51_ GCSWA 56_ LYLFL 61_ VKCTI 66_ SISTF 71_ LLLCL 76_ IVAFH 81_ AKEVQ 86_ LFMTD 91_ NGLRD 96_ WRVAL 101_ TGRQA 106_ AQIVL 111_ ELVVC 116_ GLHPA 121_ PVRGP 126_ PCVQD 131_ LGAPL 136_ TSPQP 141_ WPGFL 146_ GQGEA 151_ LLSLA 156_ MLLRL 161_ YLVPR 166_ AVLLR 171_ SGVLL 176_ NASYR 181_ SIGAL 186_ NQVRF 191_ RHWFV 196_ AKLYM 201_ NTHPG 206_ RLLLG 211_ LTLGL 216_ WLTTA 221_ WVLSV 226_ AERQA 231_ VNATG 236_ HLSDT 241_ LWLIP 246_ ITFLT 251_ IGYGD 256_ VVPGT 261_ MWGKI 266_ VCLCT 271_ GVMGV 276_ CCTAL 281_ LVAVV 286_ ARKLE 291_ FNKAE 296_ KHVHN 301_ FMMDI 306_ QYTKE 311_ MKESA 316_ ARVLQ 321_ EAWMF 326_ YKHTR 331_ RKESH 336_ AARRH 341_ QRKLL 346_ AAINA 351_ FRQVR 356_ LKHRK 361_ LREQV 366_ NSMVD 371_ ISKMH 376_ MILYD 381_ LQQNL 386_ SSSHR 391_ ALEKQ 396_ IDTLA 401_ GKLDA 406_ LTELL 411_ STALG 416_ PRQLP 421_EPSQQ
1: Intermediate conductance calcium-activated potassium channel that mediates the voltage-independent transmembrane transfer of potassium across the cell membrane through a constitutive interaction with calmodulin which binds the intracellular calcium allowing its opening (PubMed:10026195, PubMed:10961988, PubMed:11425865, PubMed:15831468, PubMed:17157250, PubMed:18796614, PubMed:26148990, PubMed:9326665, PubMed:9380751, PubMed:9407042). The current is characterized by a voltage-independent activation, an intracellular calcium concentration increase-dependent activation and a single-channel conductance of about 25 picosiemens (PubMed:9326665, PubMed:9380751, PubMed:9407042). Also presents an inwardly rectifying current, thus reducing its already small outward conductance of potassium ions, which is particularly the case when the membrane potential displays positive values, above + 20 mV (PubMed:9326665, PubMed:9380751, PubMed:9407042). Controls calcium influx during vascular contractility by being responsible of membrane hyperpolarization induced by vasoactive factors in proliferative vascular smooth muscle cell types (By similarity). Following calcium influx, the consecutive activation of KCNN4 channel leads to a hyperpolarization of the cell membrane potential and hence an increase of the electrical driving force for further calcium influx promoting sustained calcium entry in response to stimulation with chemotactic peptides (PubMed:26418693). Required for maximal calcium influx and proliferation during the reactivation of naive T-cells (PubMed:17157250, PubMed:18796614). Plays a role in the late stages of EGF-induced macropinocytosis through activation by PI(3)P (PubMed:24591580)