Topic
Mitoplast
About: Mitoplast is a research topic. Over the lifetime, 113 publications have been published within this topic receiving 6532 citations.
Papers published on a yearly basis
Papers
TL;DR: Digitonin treatment released more monoamine oxidase than cytochrome oxidase from sonic particles, thus indicating that digitonin preferentially degrades the outer mitochondrial membrane.
Abstract: Controlled osmotic lysis (water-washing) of rat liver mitochondria results in a mixed population of small vesicles derived mainly from the outer mitochondrial membrane and of larger bodies containing a few cristae derived from the inner membrane. These elements have been separated on Ficoll and sucrose gradients. The small vesicles were rich in monoamine oxidase, and the large bodies were rich in cytochrome oxidase. Separation of the inner and outer membranes has also been accomplished by treating mitochondria with digitonin in an isotonic medium and fractionating the treated mitochondria by differential centrifugation. Treatment with low digitonin concentrations released monoamine oxidase activity from low speed mitochondrial pellets, and this release of enzymatic activity was correlated with the loss of the outer membrane as seen in the electron microscope. The low speed mitochondrial pellet contained most of the cytochrome oxidase and malate dehydrogenase activities of the intact mitochondria, while the monoamine oxidase activity could be recovered in the form of small vesicles by high speed centrifugation of the low speed supernatant. The results indicate that monoamine oxidase is found only in the outer mitochondrial membrane and that cytochrome oxidase is found only in the inner membrane. Digitonin treatment released more monoamine oxidase than cytochrome oxidase from sonic particles, thus indicating that digitonin preferentially degrades the outer mitochondrial membrane.
846 citations
TL;DR: Since the removal of the outer membrane does not alter the unique coupling between oxidative phosphorylation and mitochondrial creatine kinase, it is suggested that this cooperation is the result of protein-protein proximity at the inner membrane surface.
192 citations
TL;DR: The voltage dependence of the megachannel, which favors the closed state at negative (physiological) transmembrane potentials, is re‐investigated, which confirms that MMC corresponds to the permeabilization pore.
189 citations
TL;DR: It is found that there is a lag phase between addition of an apoptogenic agent and the thread-grain transition and it is suggested that small mitochondria may serve as a transportable form of organelles (‘cargo boats’ transporting some apoptotic proteins to their nuclear targets).
Abstract: Association of mitochondrial population to a mitochondrial reticulum is typical of many types of the healthy cells. This allows the cell to organize a united intracellular power-transmitting system. However, such an association can create some difficulties for the cell when a part of the reticulum is damaged or when mitochondria should migrate from one cell region to another. It is shown that in these cases decomposition of extended mitochondria to small roundish organelles takes place (the thread-grain transition). As an intermediate step of this process, formation of beads-like mitochondria occurs when several swollen parts of the mitochondrial filament are interconnected with thin thread-like mitochondrial structures. A hypothesis is put forward that the thread-grain transition is used as a mechanism to isolate a damaged part of the mitochondrial system from its intact parts. If the injury is not repaired, spherical mitochondrion originated from the damaged part of the reticulum is assumed to convert to a small ultracondensed and presumably dead mitochondrion (this process is called 'mitoptosis'). Then the dead mitochondrion is engulfed by an autophagosome. Sometimes, an ultracondensed mitoplast co-exists with a normal mitoplast, both of them being surrounded by a common outer mitochondrial membrane. During apoptosis, massive thread-grain transition is observed which, according to Youle et al. (S. Frank et al., Dev Cell 1: 515, 2002), is mediated by a dynamin-related protein and represents an obligatory step of the mitochondria-mediated apoptosis. We found that there is a lag phase between addition of an apoptogenic agent and the thread-grain transition. When started, the transition occurs very fast. It is also found that this event precedes complete de-energization of mitochondria and cytochrome c release to cytosol. When formed, small mitochondria migrate to (and in certain rare cases even into) the nucleus. It is suggested that small mitochondria may serve as a transportable form of organelles ('cargo boats' transporting some apoptotic proteins to their nuclear targets).
153 citations
TL;DR: The results imply that SCP2 enhances mitochondrial pregnenolone production by improving transfer of mitochondrial cholesterol to cytochrome P-450scc on the inner membrane, but does not directly influence the interaction of substrate with the hemoprotein.
148 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 4 |
| 2020 | 1 |
| 2019 | 1 |
| 2018 | 3 |
| 2017 | 1 |
| 2016 | 1 |