Perkins, G., Renken, C., van der Klei, I.J., Ellisman, M.H., Neupert, W., and Frey, T.G. (2001)
Tomografia elettronica di mitocondrio dopo
l'interruzione dell'apporto di proteine associato con la deplezione Tom19.
Eur. J. Cell Biol., 80, 139-150.
In una forma mutata di Neurospora crassa, nella quale รจ stata usata la tecnica sheltered RIP (mutazione puntiforme indotta ripetutamente in
ambiente protetto) per la deplezione Tom 19, il trasportatore di proteine attraverso il percorso TOM/TIM venne arrestato per mezzo dell'aggiunta di p-fluorofenilalanine (FPA).
Usando
a mutant form of Neurospora crassa, in which sheltered RIP (repeat induced point mutation) was used to deplete Tom19, protein transport
through the TOM/TIM pathway is arrested by the addition of p-fluorophenylalanine (FPA). Using intermediate- voltage electron tomography, we have generated
three-dimensional reconstructions of 28 FPA-treated mitochondria at four time points (0-32 h) after the addition of FPA. We determined that the cristae surface area and
volume were lost in a roughly linear manner. A decrease in mitochondrial volume was not observed until after 16 h of FPA treatment. The inner boundary membrane did not
appear to shrink or contract away from the outer membrane. Interestingly, the close apposition of these membranes remained over the entire periphery, even after all of the
cristae had disappeared. The different dynamics of the shrinkage of cristae membrane and inner boundary membrane has implications for compartmentalization of electron
transport proteins. Two structurally distinct types of contact sites were observed, consistent with recently published work. We determined that the cristae in the
untreated (control) mitochondria are all lamellar. The cristae of FPA- treated mitochondria retain the lamellar morphology as they reduce in size and do not adopt tubular
shapes. Importantly, the crista junctions exhibit tubular as well as slot-like connections to the inner boundary membrane, persisting until the cristae disappear,
indicating that their stability is not dependent on continuous protein import through the complex containing Tom19.
Control Neurospora Mitochondrion Reconstructed by Electron Tomography
The outer and inner membranes were segmented and surface-rendered.
QuickTime Movies: Click on the arrow at the bottom left. You can also "grab" the slide button to slice through the mitochondrion manually.
8-hour Neurospora Mitochondrion Reconstructed by Electron Tomography
16-hour Neurospora Mitochondrion Reconstructed by Electron Tomography
32-hour Neurospora Mitochondrion Reconstructed by Electron Tomography
This page maintained by Guy Perkins
 NCMIR Web Page
Ultimo aggiornamento:
10/21/11
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