Aquaporin water channels—from transfusion medicine to malaria
Biochemical analysis of the Rhesus blood group antigen led to the serendipitous discovery of AQP1, the first molecular water channel. Found throughout nature, aquaporin water channels confer high water permeability to cell membranes. AQP1 has been characterized biophysically, and the atomic structure of AQP1 is known. Identification of the Colton blood group antigen on the extracellular domain of AQP1 allowed identification of rare individuals who are AQP1-null and manifest a subclinical form of nephrogenic diabetes insipidus. Thirteen homologous proteins exist in humans. Some transport only water (aquaporins); others transport water plus glycerol (aquaglyceroporins). These proteins are required for generation of physiological fluids (urine, cerebrospinal fluid, aqueous humor, sweat, saliva, and tears). Involvement of aquaporins in multiple clinical states is becoming recognized—renal concentration, fluid retention, blindness, skin hydration, brain edema, thermal stress, glucose homeostasis, malaria, and even arsenic poisoning. Aquaporins are particularly important in plant biology. This information now provides the challenge of developing new technologies to manipulate aquaporins for clinical or agricultural benefits.
The page was last updated on Thursday, April 21, 2016 - 10:54am