From structure to disease: the evolving tale of aquaporin biology

Abstract

Our understanding of the movement of water through cell membranes has been greatly advanced by the discovery of a family of water-specific, membrane-channel proteins - the aquaporins. These proteins are present in organisms at all levels of life, and their unique permeability characteristics and distribution in numerous tissues indicate diverse roles in the regulation of water homeostasis. The recognition of aquaporins has stimulated a reconsideration of membrane water permeability by investigators across a wide range of disciplines.

Conserved elements within first intron of aquaporin-5 (Aqp5) function as transcriptional enhancers

“…Aquaporin-5 (AQP5) is a member of a family of water channel proteins [22,23] and is expressed at high levels in the lung, salivary gland and lacrimal tissues [1][2][3][4][5][6][7][8]. In the human, mouse and rat genome, the Aqp5 gene is located in a closely spaced tandem arrangement with Aqp2 and Aqp6 [24].…”

The epithelial polarity program: machineries involved and their hijacking by cancer

“…Aquaporins (AQP) have recently emerged as potential regulators of cancer and metastasis (Hansel et al, 2004;HaraChikuma and Verkman, 2008b). AQP are a family of water transporting proteins that can also transport small neutral solutes such as glycerol and urea; their role is essential for the function of a variety of epithelial organs (King et al, 2004;Wang et al, 2006a). In polarized epithelial cells, AQP3 is sorted to the basolateral domain due to an NH 2 YRLL sorting signal (Rai et al, 2006).…”

Cytoprotective effects of growth factors: BDNF more potent than GDNF in an organotypic culture model of Parkinson's disease

“…They are composed of ~300 amino acids and have a molecular weight around 30 kDa (245). Most but not all aquaporins are inhibited by mercury, which depends on the presence of cysteines at certain positions within the aquaporin structure (246). In biological membranes, aquaporins form homotetramers containing four independent monomers, in which each serve as a pore (247,248).…”