Rhesus expression in a green alga is regulated by CO_2

摘要

The function of the Rhesus (Rh) complex in the human red cell membrane has been unknown for six decades. Based on the organismal, organ, and tissue distribution of Rh proteins, and on our evidence that their only known paralogues, the ammonium and methylammonium transport proteins (also called methylam- monium permeases), are gas channels for NH_3, we recently spec- ulated that Rh proteins are biological gas channels for CO_2. Like NH_3, CO_2 differs from other gases in being readily hydrated. We have now tested our speculation by studying expression of the RH1 gene in the photosynthetic microbe Chlamydomonas reinhardtii.