Aquaporin 5

Domain

Aquaporins contain two tandem repeats each containing three membrane-spanning domains and a pore-forming loop with the signature motif Asn-Pro-Ala (NPA).

Function

Aquaporins form homotetrameric transmembrane channels, with each monomer independently mediating water transport across the plasma membrane along its osmotic gradient (PubMed:18768791, PubMed:8621489). Plays an important role in fluid secretion in salivary glands (By similarity). Required for TRPV4 activation by hypotonicity. Together with TRPV4, controls regulatory volume decrease in salivary epithelial cells (PubMed:16571723). Seems to play a redundant role in water transport in the eye, lung and in sweat glands (By similarity).

Involvement in disease

Keratoderma, palmoplantar, Bothnian type

PPKB

A dermatological disorder characterized by diffuse non-epidermolytic hyperkeratosis of the skin of palms and soles. PPKB is frequently complicated by fungal infections.

None

The disease is caused by variants affecting the gene represented in this entry.

Sequence similarities

Belongs to the MIP/aquaporin (TC 1.A.8) family.

Tissue specificity

Detected in skin eccrine sweat glands, at the apical cell membrane and at intercellular canaliculi (at protein level).

Cellular localization

• Apical cell membrane
• Multi-pass membrane protein
• Cell membrane
• Multi-pass membrane protein
• Cytoplasmic vesicle membrane
• Multi-pass membrane protein
• Hypotonicity increases location at the cell membrane. Phosphorylation decreases location at the cell membrane.

Alternative names

• Aquaporin-5
• AQP-5
• AQP5

Database links

• entrezGene:362
• omim:600442
• swissprot:P55064

Target type

Proteins

Molecular weight

28292Da