Specific loss of LHCII phosphorylation in the Lemna mutant 1073 lacking the cytochrome b 6/f complex

FEBS Letters

Gal, Alma²  Ohad, Itzhak²  Schuster, Gadi²  Shahak, Yosepha¹ 

[1] Department of Biochemistry, The Weizmann Institute, Rehovoth, Israel;>Department of Biological Chemistry, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem Israel

关键词: Cytochrome b 6/f complex;    LHCII;    Protein phosphorylation;    Thylakoid;    (Lemna);    Chl;    chlorophyll;    cyt b 6/f;    cytochrome b 6/f complex;    DBMIB;    2;    5-dibromo-3-methyl-6-isopropyl-p-benzoquinone;    DIBB;    2;    3-diiodo-5-t-butyl-1;    4-benzoquinone;    diuron;    1;    3-dichlorophenyldimethylurea;    DQ/DQH2;    oxidized/reduced duroquinone;    LHCII;    light-harvesting chlorophyll a/b complex of photosystem II;    PQ/PQH2;    oxidized/reduced plastoquinone;    PS;    photosystem;    SDS-PAGE;    SDS-polyacrylamide gel electrophoresis;    WT;    wild type;   

DOI  :  10.1016/0014-5793(87)80926-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The thylakoid protein kinase(s) activity of Lemna perpusilla strain 6746 (wild type, WT) and the cytochrome (cyt) b ₆/f-less mutant 1073 was compared. Isolated thylakoids of both WT and mutant phosphorylated the polypeptides of 9–15, 29, 32–34 and 40–45 kDa. This kinase(s) activity was light-dependent and could be elicited by addition of duroquinol in the dark. Thylakoids from both WT and mutant phosphorylated histone III-S at comparable rates. However, the redox-controlled phosphorylation of the LHCII polypeptide which could be demonstrated in vitro and in vivo in the WT thylakoids could not be detected under any experimental condition in the cyt b ₆/f-less thylakoids. Halogenated quinone analogues known to inhibit reduction of the cyt b ₆/f complex inhibited both the electron flow and duroquinol-activated LHCII phosphorylation, but had no effect on the duroquinol-dependent phosphorylation of the other thylakoid polypeptides. These results indicate that the Lemna thylakoids contain at least two redox-activated protein kinase(s). A quinone-binding site is involved in the activation of the LHCII kinase system which is rendered inactive in the absence of the cyt b ₆/f complex.

【 授权许可】

Unknown