The nuclear origin of the non‐phosphorylating NADH dehydrogenases of plant mitochondria

FEBS Letters

Wiskich, J.T¹  Zhang, Q¹  Cook-Johnson, R.J²  Soole, K.L² 

[1]Department of Environmental Biology, University of Adelaide, South Australia, 5000 Adelaide, Australia

[2]School of Biological Sciences, The Flinders University of South Australia, 5042 Melbourne, Australia

关键词: Rotenone-insensitive;    NADH oxidation;    Protein synthesis inhibition;    Mitochondrion;    CHI;    cycloheximide;    CAP;    chloramphenicol;    SMPs;    sub-mitochondrial particles;    MDH;    malate dehydrogenase;    ME;    malic enzyme;    ETC;    electron transport chain;    CI;    Complex I;   

DOI  :  10.1016/S0014-5793(99)00753-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The oxidation of matrix and cytosolic NADH by isolated beetroot and wheat leaf mitochondria was investigated to determine whether the rotenone-insensitive NADH dehydrogenases of plant mitochondria were the products of nuclear or mitochondrial genes. After aging beetroot tissue (slicing and incubating in a CaSO₄ solution), the induction of the level of matrix NADH oxidation in the presence of rotenone was greatly reduced in mitochondria isolated from tissue treated with cycloheximide, a nuclear protein synthesis inhibitor. This was also true for the oxidation of cytosolic NADH. Mitochondria isolated from chloramphenicol-treated tissue exhibited greatly increased levels of both matrix and external rotenone-insensitive NADH oxidation when compared to the increase due to the aging process alone. This increase was not accompanied by an increase in matrix NAD-linked substrate dehydrogenases such as malic enzyme nor intra-mitochondrial NAD levels. Possible explanations for this increase in rotenone-insensitive NADH oxidation are discussed. Based on these results we have concluded that the matrix facing rotenone-insensitive NADH dehydrogenase of plant mitochondria is encoded by a nuclear gene and synthesis of the protein occurs in the cytosol.

【 授权许可】

Unknown