OTOP1
entrez
133060
canonical
uniprot
Q7RTM1
canonical
ensembl
ENSG00000163982
resolver
ensp
ENSP00000296358
resolver
enst
ENST00000296358
resolver
genesymbol
OTOP1
resolver
hgnc
HGNC:19656
resolver
uniprot
A1L476
resolver
uniprot_entry
OTOP1_HUMAN
resolver
uniprot_sec
A1L476
resolver
activity_regulation
ACTIVITY REGULATION: Activated by both acid and alkali, with proton influx in response to extracellular acid and proton efflux during alkali stimulation (By similarity). Inhibited by Zn(2+); this inhibition is thought to be pH-sensitive (PubMed:37798269). Currents evoked in response to mild acid (pH 6.0) stimulus may also be mildly potentiated by exposure to Zn(2+) (By similarity). Activated by NH(4)Cl (By similarity). {ECO:0000250|UniProtKB:Q80VM9, ECO:0000269|PubMed:37798269}.
uniprot
proteins
amino_acid_sequence
MLEGLGSPASPRAAASASVAGSSGPAACSPPSSSAPRSPESPAPRRGGVRASVPQKLAEMLSSQYGLIVFVAGLLLLLAWAVHAAGVSKSDLLCFLTALMLLQLLWMLWYVGRSSAHRRLFRLKDTHAGAGWLRGSITLFAVITVILGCLKIGYFIGFSECLSATEGVFPVTHSVHTLLQVYFLWGHAKDIIQSFKTLERFGVIHSVFTNLLLWANGVLNESKHQLNEHKERLITLGFGNITTVLDDHTPQCNCTPPTLCTAISHGIYYLYPFNIEYQILASTMLYVLWKNIGRKVDSHQHQKMQFKSDGVMVGAVLGLTVLAATIAVVVVYLIHIGRSKTKSESALIMFYLYAITLLMLMGAAGLAGIRIYRIDEKSLDESKNPARKLDSDLLVGTASGSWLISWGSILAILCAEGHPRYTWYNLPYSILAIVEKYIQNLFIFESIHREPEKLSEDIQTLRVVTVCNGNTMPLASSCPKSGGVARDVAPQGKDMPPAANGNVCMRESHDKEEEKQEESSWGGSPSPVRLPRFLQGNAKRKVLRNIAAFLFLCNISLWIPPAFGCRPEYDNGLEEIVFGFEPWIIVVNLAMPFSIFYRMHAAASLFEVYCKI
uniprot
proteins
function
FUNCTION: Proton-selective ion channel (PubMed:29371428, PubMed:36266567). Biphasically modulated by acid and alkali, mediating proton influx and efflux in response to extracellular acid and base stimulation, respectively. Sour taste receptor, which carries inward currents in response to extracellular acidification (By similarity). Sensor for ammonium chloride (NH(4)Cl) in taste receptor cells (PubMed:37798269). NH(4)Cl acts by increasing the intracellular pH, thereby generating a driving force for proton entry through OTOP1 channel (PubMed:37798269). Might also participate in alkaline sensation. Plays a role in the regulation of Ca(2+) flux in response to purigenic (ATP, ADP and UDP) stimuli, leading to increase in cytosolic Ca(2+) due to influx of extracellular calcium. May play this role by inhibiting P2Y purinoceptor-mediated Ca(2+) release in a Ca(2+)-dependent manner and promote an influx of Ca(2+) in response to ATP. Through this mechanism and possibly others, plays a role in the formation and function of calcium carbonate-based structures in the vestibular system of the inner ear, called otoconia, that sense gravity and linear acceleration. In obesity, may attenuate adipose tissue inflammation, through the negative regulation of IFNG signaling, hence may play an adaptive role in the maintainance of metabolic homeostasis. Following alkali activation, may also be permeable Na(+), K(+), Cs(+) and Li(+) (By similarity). {ECO:0000250|UniProtKB:Q80VM9, ECO:0000269|PubMed:29371428, ECO:0000269|PubMed:36266567, ECO:0000269|PubMed:37798269}.
uniprot
proteins
mass_dalton
67353
uniprot
proteins
mutagenesis
MUTAGEN 229; /note="H->Q,C,E: Complete loss of H(+) current at pH 5 and 4.5."; /evidence="ECO:0000269|PubMed:36266567"; MUTAGEN 229; /note="H->R,K,D: Abolishes proton channel activity at pH 5 and 4.5."; /evidence="ECO:0000269|PubMed:36266567"; MUTAGEN 570; /note="D->E: Does not affect cell membrane localization. Reduction of proton channel activity."; /evidence="ECO:0000269|PubMed:36266567"; MUTAGEN 570; /note="D->H: Does not affect proton channel activity."; MUTAGEN 570; /note="D->N: Does not affect cell membrane localization. Strong reduction of proton channel activity."; /evidence="ECO:0000269|PubMed:36266567
uniprot
proteins
protein_family
Otopetrin family
uniprot
proteins
pubmed
12651873
uniprot
proteins
pubmed
15489334
uniprot
proteins
pubmed
29371428
uniprot
proteins
pubmed
36266567
uniprot
proteins
pubmed
37798269
uniprot
proteins
sequence_length
612
uniprot
proteins
subcellular_location
SUBCELLULAR LOCATION: Cell membrane {ECO:0000269|PubMed:36266567}; Multi-pass membrane protein {ECO:0000250|UniProtKB:Q7ZWK8}. Cell projection, microvillus {ECO:0000250|UniProtKB:Q80VM9}. Note=Found in the gelatinous membrane overlying the inner ear macular epithelium. Also detected in the apical microvilli in inner ear supporting cells. {ECO:0000250|UniProtKB:Q80VM9}.
uniprot
proteins
transmembrane_region
TRANSMEM 59..80; /note="Helical; Name=1"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8, ECO:0000255"; TRANSMEM 89..112; /note="Helical; Name=2"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 131..153; /note="Helical; Name=3"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 164..188; /note="Helical; Name=4"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 197..223; /note="Helical; Name=5"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 265..290; /note="Helical; Name=6"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 312..334; /note="Helical; Name=7"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 345..370; /note="Helical; Name=8"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 389..413; /note="Helical; Name=9"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 424..444; /note="Helical; Name=10"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 545..563; /note="Helical; Name=11"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8"; TRANSMEM 582..605; /note="Helical; Name=12"; /evidence="ECO:0000250|UniProtKB:Q7ZWK8
uniprot
proteins