Why do microorganisms have aquaporins?
Aquaporins are channel proteins that enhance the permeability of cell membranes for water. They have been found in Bacteria, Archaea and Eukaryotes. However, their absence in many microorganisms suggests that aquaporins do not fulfill a broad role such as turgor regulation or osmoadaptation but, instead, fulfill a role that enables microorganisms to have specific lifestyles. The recent discovery that aquaporins enhance cellular tolerance against rapid freezing suggests that they have ecological relevance. We have identified several examples of large-scale freeze-thawing of microbes in nature and we also draw attention to alternative lifestyle-related functions for aquaporins, which will be a focus of future research.
Tanghe
An
A
Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Katholieke Universiteit Leuven and Flanders Interuniversity Institute for Biotechnology (VIB), Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium.
Van Dijck
Patrick
P
Thevelein
Johan M
JM
D000818:Animals; D020346:Aquaporins / Q000502:physiology*; D001105:Archaea / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D001419:Bacteria / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D044822:Biodiversity; D056890:Eukaryota / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D005615:Freezing; D005658:Fungi / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D010539:Permeability; D010641:Phenotype; D014867:Water / Q000378:metabolism
D020346:Aquaporins; D014867:Water