Transient decrease of light-harvesting complex II phosphorylation level by hypoosmotic shock in dark-adapted Dunaliella salina.
This study investigated the regulation of major light harvesting chlorophyll a/b protein (LHCII) phosphorylation by hypoosmotic shock in dark-adapted Dunaliella salina cells. When the external NaCl concentration decreased in darkness, D. salina LHCII phosphorylation levels transiently dropped within 20 min and then restored gradually to basal levels. The transient decrease in LHCII phosphorylation levels was insensitive to NaF, a phosphatase inhibitor. Inhibition of intracellular ATP production by addition of an uncoupler or an ATP synthase inhibitor increased LHCII phosphorylation levels in D. salina cells exposed to hypoosmotic shock. Taken together, these results indicate that hypoosmotic shock inhibits the LHCII phosphorylation process. The related mechanism and physiological significance are discussed.
Institute of Plant Physiology and Ecology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200032, China.
Xian-De
XD
Liu
Fen-Hong
FH
Hu
Yun-Gang
YG
Shen
D000255:Adenosine Triphosphate / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D000460:Chlorophyta / Q000187:drug effects* / Q000378:metabolism; D003624:Darkness; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D009997:Osmotic Pressure; D010766:Phosphorylation; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology*; D012969:Sodium Fluoride / Q000494:pharmacology
D004791:Enzyme Inhibitors; D045342:Light-Harvesting Protein Complexes; D045332:Photosystem II Protein Complex; D012965:Sodium Chloride; D000255:Adenosine Triphosphate; D012969:Sodium Fluoride