UniProt functional annotation for Q6J8I9



	UniProt functional annotation for Q6J8I9

UniProt code: Q6J8I9.

Organism: Ovis aries (Sheep).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae; Caprinae; Ovis.

Function: Water channel. Channel activity is down-regulated by CALM when cytoplasmic Ca(2+) levels are increased. May be responsible for regulating the osmolarity of the lens. Interactions between homotetramers from adjoining membranes may stabilize cell junctions in the eye lens core. Plays a role in cell-to-cell adhesion and facilitates gap junction coupling (By similarity). {ECO:0000250|UniProtKB:P30301, ECO:0000269|PubMed:15141214, ECO:0000269|PubMed:15351655, ECO:0000269|PubMed:16319884, ECO:0000269|PubMed:20389283, ECO:0000269|PubMed:23893133}.

Subunit: Homotetramer. Homooctamer formed by head-to-head interaction between homotetramers from adjoining membranes. Interacts with CALM; one CALM molecule interacts with the cytoplasmic domains of two aquaporins, leading to channel closure. Interacts (via C-terminus) with BFSP1 (via C-terminus) in aged lens fiber cells (By similarity). {ECO:0000250|UniProtKB:P06624, ECO:0000269|PubMed:15351655, ECO:0000269|PubMed:16319884, ECO:0000269|PubMed:20389283, ECO:0000269|PubMed:23893133}.

Subcellular location: Cell membrane {ECO:0000269|PubMed:15141214, ECO:0000269|PubMed:15351655, ECO:0000269|PubMed:23893133}; Multi-pass membrane protein {ECO:0000305}. Cell junction, gap junction {ECO:0000269|PubMed:15141214, ECO:0000269|PubMed:15351655, ECO:0000269|PubMed:23893133}.

Tissue specificity: Detected in eye lens (at protein level). {ECO:0000269|PubMed:15141214, ECO:0000269|PubMed:15351655, ECO:0000269|PubMed:23893133}.

Domain: Aquaporins contain two tandem repeats each containing two membrane-spanning helices and a pore-forming loop with the signature motif Asn-Pro-Ala (NPA). Each tandem repeat contains a loop and a short helix that enter and leave the lipid bilayer on the same side.

Ptm: Subject to partial proteolytic cleavage in the eye lens core. Partial proteolysis promotes interactions between tetramers from adjoining membranes. {ECO:0000269|PubMed:15351655}.

Ptm: Fatty acylated at Met-1 and Lys-238. The acyl modifications, in decreasing order of ion abundance, are: oleoyl (C18:1) > palmitoyl (C16:0) > stearoyl (C18:0) > eicosenoyl (C20:1) > dihomo-gamma- linolenoyl (C20:3) > palmitoleoyl (C16:1) > eicosadienoyl (C20:2). {ECO:0000250|UniProtKB:P30301}.

Similarity: Belongs to the MIP/aquaporin (TC 1.A.8) family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Ovis aries (Sheep).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae; Caprinae; Ovis.



Function:		Water channel. Channel activity is down-regulated by CALM when cytoplasmic Ca(2+) levels are increased. May be responsible for regulating the osmolarity of the lens. Interactions between homotetramers from adjoining membranes may stabilize cell junctions in the eye lens core. Plays a role in cell-to-cell adhesion and facilitates gap junction coupling (By similarity). {ECO:0000250\|UniProtKB:P30301, ECO:0000269\|PubMed:15141214, ECO:0000269\|PubMed:15351655, ECO:0000269\|PubMed:16319884, ECO:0000269\|PubMed:20389283, ECO:0000269\|PubMed:23893133}.


Subunit:		Homotetramer. Homooctamer formed by head-to-head interaction between homotetramers from adjoining membranes. Interacts with CALM; one CALM molecule interacts with the cytoplasmic domains of two aquaporins, leading to channel closure. Interacts (via C-terminus) with BFSP1 (via C-terminus) in aged lens fiber cells (By similarity). {ECO:0000250\|UniProtKB:P06624, ECO:0000269\|PubMed:15351655, ECO:0000269\|PubMed:16319884, ECO:0000269\|PubMed:20389283, ECO:0000269\|PubMed:23893133}.
Subcellular location:		Cell membrane {ECO:0000269\|PubMed:15141214, ECO:0000269\|PubMed:15351655, ECO:0000269\|PubMed:23893133}; Multi-pass membrane protein {ECO:0000305}. Cell junction, gap junction {ECO:0000269\|PubMed:15141214, ECO:0000269\|PubMed:15351655, ECO:0000269\|PubMed:23893133}.
Tissue specificity:		Detected in eye lens (at protein level). {ECO:0000269\|PubMed:15141214, ECO:0000269\|PubMed:15351655, ECO:0000269\|PubMed:23893133}.
Domain:		Aquaporins contain two tandem repeats each containing two membrane-spanning helices and a pore-forming loop with the signature motif Asn-Pro-Ala (NPA). Each tandem repeat contains a loop and a short helix that enter and leave the lipid bilayer on the same side.
Ptm:		Subject to partial proteolytic cleavage in the eye lens core. Partial proteolysis promotes interactions between tetramers from adjoining membranes. {ECO:0000269\|PubMed:15351655}.
Ptm:		Fatty acylated at Met-1 and Lys-238. The acyl modifications, in decreasing order of ion abundance, are: oleoyl (C18:1) > palmitoyl (C16:0) > stearoyl (C18:0) > eicosenoyl (C20:1) > dihomo-gamma- linolenoyl (C20:3) > palmitoleoyl (C16:1) > eicosadienoyl (C20:2). {ECO:0000250\|UniProtKB:P30301}.
Similarity:		Belongs to the MIP/aquaporin (TC 1.A.8) family. {ECO:0000305}.