AQP7 Gene - Aquaporin 7: Function, Expression, Mutations & Disease

AQP7 (Aquaporin 7) encodes a member of the aquaporin family of water-selective membrane channels. Unlike classical aquaporins, AQP7 also facilitates the transport of glycerol, urea, and other small solutes. It is highly expressed in adipose tissue, where it mediates glycerol efflux from adipocytes during lipolysis, and in the kidney, testis, and heart. AQP7 plays a critical role in energy metabolism, insulin sensitivity, and glucose homeostasis. Dysregulation of AQP7 is associated with obesity, type 2 diabetes, and metabolic syndrome.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Glycerol metabolism (Reactome: R-HSA-70326)

• Aquaporin-mediated transport (Reactome: R-HSA-445717)

• Lipolysis in adipocytes (KEGG: hsa04923)

Aquaporin 7 (AQP7) is a 342-amino acid integral membrane protein with six transmembrane helices and two NPA (Asn-Pro-Ala) motifs characteristic of aquaporins. It forms homotetramers in the plasma membrane, with each monomer functioning as an independent channel. AQP7 facilitates bidirectional water and glycerol transport, with a preference for glycerol. In adipocytes, it is the primary glycerol channel responsible for releasing glycerol produced by lipolysis into the bloodstream. Post-translational modifications include N-glycosylation at Asn-68, which is important for proper trafficking. AQP7 is regulated by insulin, which downregulates its expression, and by PPARγ agonists, which upregulate it. Structural studies show that the selectivity filter (aromatic/arginine region) allows passage of linear polyols like glycerol while excluding larger solutes.