Table 1.

Renal aquaporins.

Name	Class	Exons	Synonyms	Kidney segment	Extrarenal localization	Subcellular distribution	Function	KO mice show	References
AQP1	I	4	AQP-CHIP, CHIP28	PT, DL	Brain, erythrocytes, eye, heart, lung, pancreas, skeletal muscle, vagina	Apical and basolateral PM	Constitutive water reabsorption from pre-urine, tubular cell migration, angiogenesis	Impaired pain sensation, polyuria	Preston and Agre, 1991; Ma et al., 1998; Bai et al., 1999; Pallone et al., 2000; Vacca et al., 2001; Saadoun et al., 2005; Hara-Chikuma and Verkman, 2006; Wang et al., 2008; Kim et al., 2011b; Arrighi and Aralla, 2014
AQP2	I	4	AQP-CD, WCH-CD	CD-PC	Ear, epididymis, vagina	Intracellular vesicles, apical and basolateral PM	AVP-stimulated water reabsorption from urine	Fail to thrive, polyuria	Fushimi et al., 1993; Nielsen and Agre, 1995; Nelson et al., 1998; Merves et al., 2000; Rojek et al., 2006; Kim et al., 2011b; Arrighi and Aralla, 2014
AQP3	II	6	GLIP	CD-PC	Erythrocytes, eye, colon, conjunctiva, lung, skin, vagina	Basolateral PM	Water exit of kidney CD-PC, regulation of epidermal glycerol content	Impaired wound healing, reduced skin hydration, urinary concentration defects	Echevarria et al., 1994; Ishibashi et al., 1994; Ecelbarger et al., 1995; Ma et al., 2000, 2002; Hara et al., 2002; Kwon et al., 2002; Roudier et al., 2002; Kim et al., 2011b
AQP4	I	4	MIWC, WCH4	CD-PC	Brain, eye, lung, muscle, retinal glia, skin, stomach	Basolateral PM	Water exit of kidney CD-PC, regulation of water flow in central nervous system	Impaired vision, hearing, olfaction; urinary concentration defects	Hasegawa et al., 1994; Ma et al., 1994, 1997; Yang et al., 1997; Manley et al., 2000; Li and Verkman, 2001; Zelenina et al., 2002; Hiroaki et al., 2006; Ho et al., 2009
AQP5	I	4	–	CNT, CD-βIC	Ear, eye, lung, salivary glands, placenta, pancreas, vagina	Apical PM	Generation of saliva, tears and pulmonary secretion, unknown renal function	Impaired salivary and sweat secretion, decreased osmotic water permeability across alveolar epithelium	Raina et al., 1995; He et al., 1997; Ishida et al., 1997; Ma et al., 1999; Mhatre et al., 1999; Ma et al., 2000; Krane et al., 2001a,b; Song and Verkman, 2001; Nejsum et al., 2002; Kim et al., 2011b; Procino et al., 2011b; Wu et al., 2013
AQP6	I	4	AQP2L, HKID, KID	CNT, CD-αIC	Brain, vagina	Intracellular vesicles	Urinary acid secretion, nitrate and chloride transport	–	Ma et al., 1996; Yasui et al., 1999a,b; Ohshiro et al., 2001; Ikeda et al., 2002; Liu et al., 2005; Yasui, 2009; Kim et al., 2011b
AQP7	II	6	AQPap	PT	Adipose tissue, brain, heart, intestine, skeletal muscle, testis	Apical PM	Glycerol metabolism, arsenite uptake	Glyceroluria, obesity, smaller islet cells	Ishibashi et al., 1997a, 2000a; Kishida et al., 2000; Nejsum et al., 2000; Liu et al., 2002; Hara-Chikuma et al., 2005; Hibuse et al., 2005; Sohara et al., 2005, 2006a; Laforenza et al., 2013
AQP8	I	6	–	PT	Brain, pancreas, placenta, salivary glands, sperm, testis	Intracellular vesicles, PM	Urea, amonia and ROS transport	Mild hypertriglyceridemia	Ishibashi et al., 1997b; Elkjaer et al., 2001; Yang et al., 2005; Bienert et al., 2007; Saparov et al., 2007; Kobayashi and Yasui, 2010; Tamma et al., 2011b
AQP11	III	3	AQPX1	PT	Brain, intestine, liver, testis, thymus	ER	ER homeostasis, spermiogenesis, salivary gland development	Polycystic kidney disease	Ishibashi et al., 2000b; Morishita et al., 2004, 2005b; Gorelick et al., 2006; Ishibashi, 2006; Yakata et al., 2007; Larsen et al., 2010; Yeung and Cooper, 2010

AQPap, AQP adipose; AQP2L, AQP2 like; CD-aIC, collecting duct a-intercalated cells; CD-bIC, collecting duct b-intercalated cells; CD-PC, collecting duct principal cells; Class I, classical aquaporins; Class II, aquaglyceroporins; Class III, superaquaporins, unorthodox AQPs, subcellular AQPs; CNT, connecting tubule; DL, descending limb of Henle; ER, endoplasmatic reticulum; GLIP, glucagon-like insulinotropic peptide; HKID, original name of the clone (Ma et al., 1996); KO, knock out; MIP, major intrinsic protein; MIWC, mercurial-insensitive water channel; PM, plasma membrane; PT, proximal tubule; SSC1, small solute channel 1; WCH4, water channel 4.