Interactions of mitochondria with the actin cytoskeleton

Abstract

Interactions between mitochondria and the cytoskeleton are essential for normal mitochondrial morphology, motility and distribution. While microtubules and their motors have been established as important factors for mitochondrial transport, emerging evidence indicates that mitochondria interact with the actin cytoskeleton in many cell types. In certain fungi, such as the budding yeast and Aspergillus, or in plant cells mitochondrial motility is largely actin-based. Even in systems such as neurons, where microtubules are the primary means of long-distance mitochondrial transport, the actin cytoskeleton is required for short-distance mitochondrial movements and for immobilization of the organelle at the cell cortex. The actin cytoskeleton is also involved in the immobilization of mitochondria at the cortex in cultured tobacco cells and in budding yeast. While the exact nature of these immobilizations is not known, they may be important for retaining mitochondria at sites of high ATP utilization or at other cellular locations where they are needed. Recent findings also indicate that mutations in actin or actin-binding proteins can influence mitochondrial pathways leading to cell death. Thus, mitochondria-actin interactions contribute to apoptosis.

Myosin XI-K Is Required for Rapid Trafficking of Golgi Stacks, Peroxisomes, and Mitochondria in Leaf Cells of Nicotiana benthamiana

“…This same myosin is also required for the proper inheritance of yeast mitochondria, although its role might be indirect (Boldogh and Pon, 2006). Given the close phylogenetic relations between class V and class XI myosins, this overlap in functional profiles suggests that functions of myosin XI-K and XI-2 in organelle trafficking might descend directly from the original function of the ancient myosin V. The remarkable proliferation of the class XI myosins in plants (Fig.…”

“…Their inheritance and position within the cell are tightly regulated throughout the cell cycle (Pruyne et al, 2004;Weisman, 2006). The required translocations of organelles generally depend on cytoskeletal motility systems (Vale, 2003;Boldogh and Pon, 2006). Although plant cells are less motile than animal cells, they exhibit extensive intracellular dynamics that involve repositioning of the nucleus, reshaping of the vacuole, and rapid trafficking of the Golgi stacks, mitochondria, and peroxisomes (Shimmen and Yokota, 2004;Wada and Suetsugu, 2004;Matheson et al, 2006).…”

Mdm38 protein depletion causes loss of mitochondrial K+/H+ exchange activity, osmotic swelling and mitophagy

“…Maintenance and inheritance of mitochondria also involve active movement along cytoskeletal elements. 3 Mutants with defects in the fusion process contain numerous spherical fragmented mitochondria. In contrast, fission defects result in net-like agglomerations of mitochondria.…”

Apoptosis and the yeast actin cytoskeleton

“…58 Links between the mitochondria and the actin cytoskeleton have been shown in divergent eukaryotic systems. 59 For example, actin is required to concentrate mitochondria in areas of cells with high energy demands, 60 and it facilitates distribution as cells undergo division. 61 In yeasts, mitochondria are thought to directly associate with actin cables through a protein complex termed mitochore, which comprises three mitochondrial transmembrane proteins (Mdm10p, Mdm12p and Mmm1p).…”