[Role of transmembrane GTPases in mitochondrial morphology and activity].

Mitochondria play crucial role in the energetic metabolism, thermogenesis, maintenance of calcium homeostasis and apoptosis. Cyclic changes in fusion and fission of mitochondria are required for properly functioning organelles, especially in tissues with high dependence on energy supply such as skeletal muscles, heart, or neurons. The key role of mitochondrial fusion is observed in embryonic development and maintaining unchanged mtDNA pool under conditions of oxidative stress. There is a large number of data indicating that mitochondrial networks often accompany the resistance to apoptotic stimuli. In contrast to fusion--the mitochondrial fission precedes apoptosis. According to the newest knowledge precise interactions between a few proteins are required for mitochondrial fusion and division. Among them Drp1, Mfn1, Mfn2 and Opal are considered the most important. Recent reports shed some light on the physiological importance of proteins participating in mitochondrial membrane dynamics in energy production, apoptosis and cellular signaling. In this review the authors report on the recent knowledge concerning structural changes of mitochondria with a particular interest to transmembrane GTPases and their role in cellular physiology.