BAND-3, THE ANION TRANSPORTER, IS CONSERVED DURING EVOLUTION - IMPLICATIONS FOR AGING AND VERTEBRATE EVOLUTION

A cDNA fragment corresponding to a highly evolutionarily conserved reg ion of the major anion transport protein band 3 was cloned from lampre y mRNA using PCR homology probing. This is the first report providing evidence for a band-3 like transporter in the lowest vertebrates, the agnathostomes. Semi-quantitative PCR showed expression similar to that of higher vertebrates. Lamprey serum contains antibody-like molecules that bind to synthetic peptides of band 3 comprising senescent cell a ntigen, an aging antigen that terminates the life of cells. The high d egree of homology found in nucleic acid and derived proteins sequence and the reaction of ''antibodies'' in lamprey serum with senescent cel l antigen peptides of band 3 suggests that lamprey band 3 plays a role comparable to that in higher vertebrates.