Mitochondrial Protein in the Nucleus

• 作者: Bor Luen Tang
• 来源期刊: 细胞生物学(英文)
• 学科: 医学
• 关键词: Fumarase Pyrivate DEHYDROGENASE COMPLEX (PDC) CLK-1 COQ7 MITOCHONDRIA NUCLEUS
• 年，卷（期）: 2015,（2）
• 页码范围: 23-29
• 页数: 7页
• 分类号: R73

摘要

Other than the respiratory chain components, most mitochondrial proteins are synthesized in the cytosol and imported into the mitochondria. Many mitochondrial proteins therefore have at least a transient cytosolic appearance, and several have a dual mitochondrial-cytosol functional localization. However, recent work has revealed several proteins, one of which is a large protein complex, with dual mitochondrial and nuclear localizations. The enzyme fumarase which catalyzes the reversible hydration/dehydration of fumarate to malate is part of the mitochondria matrix tricarboxylic acid (TCA) cycle. It could, however, be recruited from the cytosol to the nucleus in response to DNA damage, where it is important for DNA repair. The pyruvate dehydrogenase complex (PDC) generates acetyl-CoA from pyruvate, and is recently shown to translocate from the mitochondrial matrix into the nuclear under mitogenic and stress conditions to generate acetyl–CoA within the nucleus. The mitochondrial monooxygenase CLK-1/COQ7 responsible for the synthesis of ubiquinone is most recently found to have a nuclear isoform with an uncleaved amino terminus, where it affects transcriptional changes associated with mitochondrial reactive oxygen species (ROS) generation. In this review, we highlight these unusual cases of nuclear localization of classically mitochondrial proteins, and discuss their possible functions in the nucleus.