Table 5.
Summary of key properties of AQPs
| Aquaporins | Organism | Main location | Our findings in the GI tract | Comment | References |
|---|---|---|---|---|---|
| AQP0 | Mammals | Lens | na | AQP | 57 |
| AQP1 | Mammals | Red blood cells | Reduced amounts in ileum in CD | AQP | 58 |
| Kidney | 59 | ||||
| Lung | 60 | ||||
| Vascular endothelium | This study | ||||
| Brain, eye: glial cells | |||||
| Neurons | |||||
| AQP2 | Mammals | Kidney | na | AQP | 82 |
| Vas deferens | 61 | ||||
| Neurons | 62 | ||||
| AQP3 | Mammals | Kidney | Reduced amounts in ileum in CD | Aquaglyceroporin | 63 |
| Skin | Water, glycerol, urea | This study | |||
| Lung | |||||
| Eye | |||||
| Colon | |||||
| AQP4 | Mammals | Brain, muscle, kidney, lung, stomach, small intestine | – | AQP | 64 |
| Main AQP in the brain | 65 | ||||
| 66 | |||||
| Neurons | |||||
| Vascular endothelium | |||||
| AQP5 | Mammals | Salivary/lacrimal gland | – | AQP | 67 |
| Sweat gland | 68 | ||||
| Lung | 27 | ||||
| Cornea | |||||
| AQP6 | Mammals | Kidney | na | AQP | 7 |
| Anion channel | |||||
| AQP7 | Mammals | Adipose tissue | Reduced amounts | Aquaglyceroporin | 69 |
| Kidney | in ileum and | Water, glycerol, urea, arsenite | This study | ||
| Testis | colon in UC | ||||
| AQP8 | Mammals | Testis, kidney, liver, pancreas, small intestine, colon | Reduced amounts in ileum and colon in UC | AQP | 70 |
| This study | |||||
| AQP9 | Mammals | Liver, leukocytes, brain, testis | – | Aquaglyceroporin | 71 |
| Water, glycerol, urea, arsenite | |||||
| AQP10 | Mammals | Small intestine | na | Aquaglyceroporin | 72 |
| Kidney | Water, glycerol, urea | 6 | |||
| AQP11 | Mammals | Kidney ER | na | Super-AQP | 73 |
| Divergent NPA motif, sign cysteine | |||||
| AQP12 | Mammals | Pancreas | na | Super-AQP | 74 |
| Divergent NPA motif, sign cysteine | |||||
| AQPZ | E. coli, Mycobacterium abscessus* | na | na | AQP | 75 |
| This study* | |||||
| GlpF | E. coli, Haemophilus influenzae, Streptococcus pyogenes* | na | na | Aquaglyceroporin | 75 |
| 76 | |||||
| This study* | |||||
| AQY1/2 | Yeast | na | na | AQP | 77 |
| 78 | |||||
| GLPY1/2 | Yeast | na | na | Aquaglyceroporin | 79 |
| PIPs/TIPs/ | Plants | na | na | AQP | 80 |
| NIPs/SIPs | 81 |
Note: – indicates not detected above threshold in the gut.
Abbreviations: AQP, aquaporin; AQPZ, aquaporin-related pore; na, not applicable; E. coli, Escherichia coli; ER, endoplasmic reticulum; glpF, glycerol facilitator; GI, gastrointestinal; NPA, asparagine-proline-alanine; CD, Crohn’s disease; NIPs, nodulin 26-like intrinsic membrane proteins; PIPs, plasma membrane intrinsic proteins; SIPs, small basic intrinsic proteins; TIPs, tonoplast intrinsic proteins; UC, ulcerative colitis; AQY1/2, yeast aquaporin; GLPY1/2, yeast glycerol facilitation-like protein.