Invertebrate aquaporins: a review.
Aquaporins (AQPs) or water channels render the lipid bilayer of cell membranes permeable to water. The numerous AQP subtypes present in any given species, the transport properties of each subtype and the variety of methods of their regulation allows different cell types to be transiently or permanently permeable to water or other solutes that AQPs are capable of transporting (e.g. urea or glycerol). AQPs have been well characterized in all vertebrate classes, other than reptilia. Here we review the current state of knowledge of invertebrate AQPs set in the context of the much more thoroughly studied vertebrate AQPs. By phylogenetic analysis of the total AQP complement of several completed insect genomes, we propose a classification system of insect AQPs including three sub-families (DRIP, BIB and PRIP) that have one representative from all the complete insect genomes. The physiological role of AQPs in invertebrates (insects, ticks and nematodes) is discussed, including their function in common invertebrate phenomena such as high-volume liquid diets, cryoprotection and anhydrobiosis.
Campbell
Ewan M
EM
Institute of Biological and Environmental Sciences School of Biological Sciences (Zoology), University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
Ball
Andrew
A
Hoppler
Stefan
S
Bowman
Alan S
AS
D000595:Amino Acid Sequence; D000818:Animals; D020346:Aquaporins / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002463:Cell Membrane Permeability; D019143:Evolution, Molecular; D019476:Insect Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D007313:Insecta / Q000235:genetics / Q000378:metabolism*; D007448:Invertebrates / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D014867:Water / Q000378:metabolism; D014882:Water-Electrolyte Balance
D020346:Aquaporins; D019476:Insect Proteins; D014867:Water