Recombinant Human Aquaporin-5 (AQP5) Protein

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)

Subcellular Location

Apical cell membrane (Multi-pass membrane protein); Cell membrane (Multi-pass membrane protein); Cytoplasmic vesicle membrane (Multi-pass membrane protein)

Disease Association

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

Tissue Specificity

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

Subunit

Homotetramer; each monomer provides an independent water pore (PubMed:18768791, PubMed:26569106). Interacts with TRPV4; the interaction is probably indirect and regulates TRPV4 activation by hypotonicity

• Lee M.D. et al. The human aquaporin-5 gene. Molecular characterization and chromosomal localization. — J. Biol. Chem. (1996)
• Ebert L. et al. Cloning of human full open reading frames in Gateway(TM) system entry vector (pDONR201). (JUN-)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Liu X. et al. A role for AQP5 in activation of TRPV4 by hypotonicity: concerted involvement of AQP5 and TRPV4 in regulation of cell volume recovery. — J. Biol. Chem. (2006)
• Inoue R. et al. Immunolocalization and translocation of aquaporin-5 water channel in sweat glands. — J. Dermatol. Sci. (2013)
• Horsefield R. et al. High-resolution X-ray structure of human aquaporin 5. — Proc. Natl. Acad. Sci. U.S.A. (2008)
• Kitchen P. et al. Plasma Membrane Abundance of Human Aquaporin 5 Is Dynamically Regulated by Multiple Pathways. — PLoS ONE (2015)
• Blaydon D.C. et al. Mutations in AQP5, encoding a water-channel protein, cause autosomal-dominant diffuse nonepidermolytic palmoplantar keratoderma. — Am. J. Hum. Genet. (2013)