Motz Christian, Martin Heiko, Krimmer Thomas, Rassow Joachim
Institut für Mikrobiologie, Universität Hohenheim, Garbenstr. 30, Stuttgart-Hohenheim, Germany.
J Mol Biol. 2002 Nov 1;323(4):729-38. doi: 10.1016/s0022-2836(02)00995-6.
The bcl-2 gene encodes a 26kDa protein which functions as a central regulator of apoptosis. Here we investigated the pathway of Bcl-2alpha into the mitochondrial outer membrane using the yeast Saccharomyces cerevisiae as a model organism. We found that interactions of Bcl-2alpha with the mitochondrial import receptor Tom20 are dependent on two positively charged lysine residues in the immediate vicinity of the carboxy-terminal hydrophobic membrane anchor. The targeting function of these residues is independent of Tom22. Subsequent insertion of Bcl-2alpha into the mitochondrial outer membrane does not require Tom5 or Tom40, indicating that Bcl-2alpha bypasses the general import pore (GIP). Bcl-2alpha shows a unique pattern of interactions with the components of the mitochondrial TOM complex, demonstrating that at least two different pathways lead from the import receptor Tom20 into the mitochondrial outer membrane.
bcl-2基因编码一种26kDa的蛋白质，其作为细胞凋亡的核心调节因子发挥作用。在此，我们以酿酒酵母作为模式生物，研究了Bcl-2α进入线粒体外膜的途径。我们发现，Bcl-2α与线粒体导入受体Tom20的相互作用依赖于羧基末端疏水膜锚定附近的两个带正电荷的赖氨酸残基。这些残基的靶向功能独立于Tom22。随后Bcl-2α插入线粒体外膜不需要Tom5或Tom40，这表明Bcl-2α绕过了一般导入孔（GIP）。Bcl-2α与线粒体TOM复合体的组分呈现出独特的相互作用模式，表明从导入受体Tom20到线粒体外膜至少有两条不同的途径。
