[Sodium ion transportation system and its possible mechanisms in bacteria].
Sodium ion with high concentration is toxic to living cells, and microorganisms adapt to the environment containing high concentration of salt by the strategies of salt-in-cytoplasm and compatible solutes. The Na+ extrusion system plays important roles in maintaining cytoplasmic Na+ homeostasis and pH level in microbial cells. Two possible mechanisms of Na+ circulation across the cytoplasmic membrane have been proposed, namely primary Na+ pump and secondary Na+/H+ antiporter. Primary sodium pumps coupled the extrusion of Na+ to respiration, and the activity of which was insensitive to uncoupler CCCP ( carbonyl-cyanide m-chlorophenylhydrazone). There were two types of secondary Na+/H+ antiporters-encoding genes designated single gene and multiple subunits, respectively. The types of transportation systems for Na+, possible mechanisms of Na+ extrusion, and projects for further study in bacteria are reviewed.
Yang
Li-Fu
LF
Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Key Laboratory of Physiology for Tropical Crops of Ministry of Agriculture, Danzhou 571737, China. ylfri@126.com
Zhao
Bai-Suo
BS
Yang
Su-Sheng
SS
D001419:Bacteria / Q000378:metabolism*; D017136:Ion Transport; D012964:Sodium / Q000276:immunology*; D017923:Sodium-Hydrogen Exchangers / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology
D017923:Sodium-Hydrogen Exchangers; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase