Bicarbonate transporters

Respiratory oxidation in the mitochondria produces carbon dioxide (CO2) as a waste product. CO2 is in equilibrium with bicarbonate (HCO3-) and is the body's central pH buffering system. HCO3- is charged so cannot move across membranes unaided. The bicarbonate transport proteins move bicarbonate across the membrane. There are 14 genes which encode these transport proteins in mammals. Applying the Human Genome Organization's sytematic nomenclature to human genes, the bicarbonate transporters belong to the SLC4A and SLC26A families. Within SLC4A, there are two distinct subfamilies, functionally corresponding to the electroneutral Cl-/HCO3- exchangers and Na+-coupled HCO3- co-transporters (Romero MF et al, 2004; Cordat E and Casey JR, 2009).

线粒体中的呼吸氧化作用产生二氧化碳（CO2）作为代谢废物。CO2与碳酸氢盐（HCO3-）处于平衡状态，构成机体核心的pH缓冲体系。由于HCO3-带电，因此无法在无辅助条件下穿越细胞膜。碳酸氢盐转运蛋白负责将碳酸氢盐跨膜转运。哺乳动物中存在14个基因编码这些转运蛋白。根据人类基因组组织的系统命名法，碳酸氢盐转运蛋白隶属于SLC4A和SLC26A家族。在SLC4A家族中，存在两个不同的亚家族，功能上分别对应电中性的Cl-/HCO3-交换体和钠离子偶联的HCO3-共转运蛋白（Romero MF等，2004；Cordat E和Casey JR，2009）。