Control of mitochondrial protein import by pH

FEBS Letters

Kinnally, Kathleen W²  Grigoriev, Sergey M²  Jensen, Robert E¹ 

[1] Department of Cell Biology, Johns Hopkins School of Medicine, Biophysics, 100 725 N. Wolfe St., Baltimore, MD 21205, USA;Division of Basic Sciences, New York University College of Dentistry, 345 East 24th St., New York, NY 10010, USA

关键词: Mitochondrion;    Protein import;    Translocase of inner membrane;    Translocase of outer membrane;    Patch clamp;    pH;    TOM;    translocase of outer membrane;    TIM;    translocase of inner membrane;   

DOI  :  10.1016/S0014-5793(03)01012-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Protein import into mitochondria is inhibited by protons (IC₅₀ pH 6.5). The channels of the import machinery were examined to further investigate this pH dependence. TOM and TIM23 are the protein translocation channels of the mitochondrial outer and inner membranes, respectively, and their single channel behaviors at various pHs were determined using patch-clamp techniques. While not identical, increasing H⁺ concentration decreases the open probability of both TIM23 and TOM channels. The pattern of the pH dependences of protein import and channel properties suggests TIM23 open probability can limit import of nuclear-encoded proteins into the matrix of yeast mitochondria.

【 授权许可】

Unknown