Akuaforinler

Abstract

Aquaporins (AQP) are integral membrane proteins that serve as channels in the transfer of water across
the membrane. Bacteria, plants and animals involve AQPs. Aquaporins are water channels that belong to the
major intrinsic proteins (MIP) family. MIPs play a major role in the regulation of membrane water permeability.
Living organisms exhibit more than 450 MIPs and among them 13 AQP are vertebrata aquaporins (AQP 0 to 12).
Mammalian aquaporins of two subgroups have been defi ned on the basis of their permeability characteristics.
The aquaporins (AQP 0,1,2,4,5,6 and 8) are highly selective for water, whereas the aquaglyceroporins are also
solutes (AQP9) in addition to water. In plant cells, aquaporins have been found in the plasma membrane and
tonoplast. Thus, control of the water fl ux into and out of a cytosol or vacuole and changes in turgor or cell size
are controlled. Aquaporins which are found in microorganisms enhance cellular tolerance against rapid freezing.
Aquaporins are involved in many cellular and physiological processes and mutations in aquaporins have been
shown to trigger pathological conditions.