AQP5

Aquaporin 5 (AQP5) is a water channel protein. Aquaporins are a family of small integral membrane proteins related to the major intrinsic protein (MIP or AQP0). Aquaporin 5 plays a role in the generation of saliva, tears and pulmonary secretions. AQP0, AQ

Full Name

Aquaporin 5

Function

Forms a water-specific channel (PubMed:8621489, PubMed:18768791).
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).

Biological Process

Camera-type eye morphogenesis Source: Ensembl
Carbon dioxide transport Source: UniProtKB
Cellular hypotonic response Source: UniProtKB
Odontogenesis Source: UniProtKB
Pancreatic juice secretion Source: UniProtKB
Protein homotetramerization Source: UniProtKB
Saliva secretion Source: Ensembl
Water transport Source: UniProtKB

Cellular Location

Apical cell membrane; Cell membrane; Cytoplasmic vesicle membrane. Hypotonicity increases location at the cell membrane. Phosphorylation decreases location at the cell membrane.

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.

Topology

Cytoplasmic: 1-12 aa
Helical: 13-33 aa
Extracellular: 34-39 aa
Helical: 40-60 aa
Cytoplasmic: 61-65 aa
Discontinuously helical: 66-74 aa
Cytoplasmic: 75-87 aa
Helical: 88-108 aa
Extracellular: 109-126 aa
Helical: 127-147 aa
Cytoplasmic: 148-158 aa
Helical: 159-179 aa
Extracellular: 180 aa
Discontinuously helical: 181-191 aa
Extracellular: 192-203 aa
Helical: 204-224 aa
Cytoplasmic: 225-265 aa