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aquaporin-1; AQP-1; aquaporin-CHIP; water channel protein for erythrocytes & kidney proximal tubule; urine water channel (AQP1, CHIP28)
Function:
- forms a water-specific channel that provides plasma membranes of red cells & kidney proximal tubules with high permeability to water, permitting water to move in the direction of an osmotic gradient
- homotetramer
Structure:
- aquaporins contain two tandem repeats each containing 3 membrane-spanning domains & a pore-forming loop with the signature motif Asn-Pro-Ala (NPA)
- belongs to the MIP/aquaporin (TC 1.A.8) family
Compartment: membrane
Expression:
- expressed in a number of tissues including erythrocytes, renal tubules, retinal pigment epithelium, heart, lung, skeletal muscle, kidney & pancreas
- weakly expressed in brain, placenta & liver
Pharmacology:
- inhibited by submillimolar concentrations of mercury
Polymorphism: responsible for Colton blood group system
General
aquaporin
glycoprotein
phosphoprotein
transmembrane 8 protein
Properties
SIZE: entity length = 269 aa
MW = 29 kD
COMPARTMENT: plasma membrane
MOTIF: cytoplasmic domain {2-7}
transmembrane domain {8-36}
exoplasmic loop {37-48}
MOTIF: N-glycosylation site {N42}
transmembrane domain {49-66}
MOTIF: phenylalanine residue {56}
cytoplasmic loop {67-70}
In membrane {71-76}
peptide motif {76-78}
transmembrane domain {77-84}
cytoplasmic loop {85-94}
transmembrane domain {95-115}
exoplasmic loop {116-136}
transmembrane domain {137-155}
cytoplasmic loop {156-166}
MOTIF: arginine-rich region {159-162}
MOTIF: arginine residue (SEVERAL)
transmembrane domain {167-183}
MOTIF: histidine residue {180}
exoplasmic loop {184-186}
In membrane {187-192}
MOTIF: cysteine residue {189}
peptide motif {192-194}
transmembrane domain {193-200}
MOTIF: arginine residue {195}
exoplasmic loop {201-207}
MOTIF: N-glycosylation site {N205}
transmembrane domain {208-228}
cytoplasmic domain {229-269}
MOTIF: Thr phosphorylation site {T246}
Ser phosphorylation site {S247}
Ser phosphorylation site {S262}
Database Correlations
OMIM correlations
MORBIDMAP 107776
UniProt P29972
Pfam PF00230
Entrez Gene 358
Kegg hsa:358
References
- UniProt :accession P29972
- dbRBC/BGMUT; Note: Blood group antigen gene mutation database
http://www.ncbi.nlm.nih.gov/gv/mhc/xslcgi.cgi?cmd=bgmut/systems_info&system=colton
- SeattleSNPs
http://pga.gs.washington.edu/data/aqp1/
- Protein Spotlight; Note: Liquid states - Issue 36 of July 2003
http://www.expasy.org/spotlight/back_issues/sptlt036.shtml