Potassium channel subfamily K member 3 (Acid-sensitive potassium channel protein TASK-1) (TWIK-related acid-sensitive K(+) channel 1) (Two pore potassium channel KT3.1) (Two pore K(+) channel KT3.1)
1_MKRQN 6_ VRTLA 11_ LIVCT 16_ FTYLL 21_ VGAAV 26_ FDALE 31_ SEPEL 36_ IERQR 41_ LELRQ 46_ QELRA 51_ RYNLS 56_ QGGYE 61_ ELERV 66_ VLRLK 71_ PHKAG 76_ VQWRF 81_ AGSFY 86_ FAITV 91_ ITTIG 96_ YGHAA 101_ PSTDG 106_ GKVFC 111_ MFYAL 116_ LGIPL 121_ TLVMF 126_ QSLGE 131_ RINTL 136_ VRYLL 141_ HRAKK 146_ GLGMR 151_ RADVS 156_ MANMV 161_ LIGFF 166_ SCIST 171_ LCIGA 176_ AAFSH 181_ YEHWT 186_ FFQAY 191_ YYCFI 196_ TLTTI 201_ GFGDY 206_ VALQK 211_ DQALQ 216_ TQPQY 221_ VAFSF 226_ VYILT 231_ GLTVI 236_ GAFLN 241_ LVVLR 246_ FMTMN 251_ AEDEK 256_ RDAEH 261_ RALLT 266_ RNGQA 271_ GGGGG 276_ GGSAH 281_ TTDTA 286_ SSTAA 291_ AGGGG 296_ FRNVY 301_ AEVLH 306_ FQSMC 311_ SCLWY 316_ KSREK 321_ LQYSI 326_ PMIIP 331_ RDLST 336_ SDTCV 341_ EQSHS 346_ SPGGG 351_ GRYSD 356_ TPSRR 361_ CLCSG 366_ APRSA 371_ ISSVS 376_ TGLHS 381_ LSTFR 386_GLMKR
1: K(+) channel that conducts voltage-dependent outward rectifying currents upon membrane depolarization. Voltage sensing is coupled to K(+) electrochemical gradient in an 'ion flux gating' mode where outward but not inward ion flow opens the gate (PubMed:23169818, PubMed:26919430, PubMed:32499642, PubMed:36195757, PubMed:9312005). Changes ion selectivity and becomes permeable to Na(+) ions in response to extracellular acidification. Protonation of the pH sensor His-98 stabilizes C-type inactivation conformation likely converting the channel from outward K(+)-conducting, to inward Na(+)-conducting to nonconductive state (PubMed:22948150). Homo- and heterodimerizes to form functional channels with distinct regulatory and gating properties (PubMed:23169818, PubMed:32499642). Allows K(+) currents with fast-gating kinetics important for the repolarization and hyperpolarization phases of action potentials (By similarity). In cerebellar granule cells, heteromeric KCNK3:KCNK9 channel may hyperpolarize the resting membrane potential to limit intrinsic neuronal excitability, but once the action potential threshold is reached, it may support high-frequency action potential firing and increased neuronal excitability (By similarity). Dispensable for central chemosensory respiration i.e. breathing controlled by brainstem CO2/pH, it rather conducts pH-sensitive currents and controls the firing rate of serotonergic raphe neurons involved in potentiation of the respiratory chemoreflex. Additionally, imparts chemosensitivity to type 1 cells in carotid bodies which respond to a decrease in arterial oxygen pressure or an increase in carbon dioxide pressure or pH to initiate adaptive changes in pulmonary ventilation (By similarity). In adrenal gland, contributes to the maintenance of a hyperpolarized resting membrane potential of aldosterone-producing cells at zona glomerulosa and limits aldosterone release as part of a regulatory mechanism that controls arterial blood pressure and electrolyte homeostasis (By similarity). In brown adipocytes, mediates K(+) efflux that counteracts norepinephrine-induced membrane depolarization, limits Ca(2+) efflux and downstream cAMP and PKA signaling, ultimately attenuating lipid oxidation and adaptive thermogenesis (By similarity)