Cl-/HCO3- exchanger transport Authored: Jassal, B, 2009-06-04 Edited: Jassal, B, 2009-06-04 Pubmed2594752 Pubmed3015590 Pubmed7506871 Pubmed7530501 Pubmed7923606 Pubmed8206915 Pubmed9312167 Reactome Database ID Release 43425482 Reactome, http://www.reactome.org ReactomeREACT_19263 Reviewed: He, L, 2009-08-24 The proteins responsible for the exchange of Cl- with HCO3- are members of the SLC4 (1-3) and SLC26 (3, 4, 6, 7 and 9) transporter families. The SLC26 members are discussed under the section "Multifunctional anion exchangers".<br><br>SLC4A1 (Band 3, AE1, anion exchanger 1) was the first bicarbonate transporter gene to be cloned and sequenced (Lux SE et al, 1989). It is ubiquitous throughout vertebrates and in humans, is present on erythrocytes and the basolateral surfaces of kidney cells. The erythrocyte and kidney forms are different isoforms of the same protein (Kollert-Jons A et al, 1993). Mutations of erythroid AE1 determine the Diego blood group system (Bruce LJ et al, 1994). A more serious consequence of mutated erythroid AE1 is Hereditary spherocytosis (a disorder leading to haemolytic anaemia) (Jarolim P et al, 1995). Defects in the kidney form of AE1 cause distal (type1) renal tubular acidosis (an inability to acidify urine) (Bruce LJ et al, 1997).<br><br>SLC4A2 (Non-erythroid band 3-like protein, AE2, anion exchanger 2) is widely expressed and is considered to be the 'housekeeping' isoform of the bicarbonate transporters (Demuth DR et al, 1986). SLC4A3 (Cardiac/brain band 3-like protein, AE3) is expressed in heart and brain (Yannoukakos D et al, 1994).<br><br>