The Role of Yeast VDAC Genes on the Permeability of the Mitochondrial Outer Membrane

Lee, Acw; Xu, Xin; Blachly-Dyson, Elizabeth; Forte, Michael; Colombini, Marco

doi:10.1007/s002329900324

Cited by 146 publications

(111 citation statements)

References 24 publications

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“…The three voltage-dependent anion channels (VDAC) 1/2/3 isoforms and the coiled-coil helix coiled-coil helix domain-containing protein 3 (CHCHD3), also known as Mic19, were identified as putative interacting partners for the GA and GB C-terminal tail. Mitochondria from yeast strain M22-2-1 deficient for porin 1 and 2, the two yeast orthologs of VDAC, 39 were unable to import efficiently GB (Supplementary Figures 3B and C) as well as 35 S-Met SU9-DHFR (Supplementary Figure 3D), because of their reduced membrane potential (Supplementary Figure 3E). Similar results were obtained from mouse liver mitochondria pretreated with S-18, a peptide inhibitor of VDAC 40 (Supplementary Figures 3F and I).…”

Section: Resultsmentioning

confidence: 99%

Granzyme B enters the mitochondria in a Sam50-, Tim22- and mtHsp70-dependent manner to induce apoptosis

et al. 2017

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We have found that granzyme B (GB)-induced apoptosis also requires reactive oxygen species resulting from the alteration of mitochondrial complex I. How GB, which does not possess a mitochondrial targeting sequence, enter this organelle is unknown. We show that GB enters the mitochondria independently of the translocase of the outer mitochondrial membrane complex, but requires instead Sam50, the central subunit of the sorting and assembly machinery that integrates outer membrane β-barrel proteins. Moreover, GB breaches the inner membrane through Tim22, the metabolite carrier translocase pore, in a mitochondrial heat-shock protein 70 (mtHsp70)-dependent manner. Granzyme A (GA) and caspase-3 use a similar route to the mitochondria. Finally, preventing GB from entering the mitochondria either by mutating lysine 243 and arginine 244 or depleting Sam50 renders cells more resistant to GB-mediated reactive oxygen species and cell death. Similarly, Sam50 depletion protects cells from GA-, GM-and caspase-3-mediated cell death. Therefore, cytotoxic molecules enter the mitochondria to induce efficiently cell death through a noncanonical Sam50-, Tim22-and mtHsp70-dependent import pathway.Cytotoxic lymphocytes eradicate pathogen-infected or transformed cells mainly through the cytotoxic granule pathway. [1][2][3][4] Among the five human granzymes (A, B, H, K and M), granzyme B (GB) triggers cell death in both a caspasedependent and caspase-independent manner, although human and mouse GB differ in their requirement for caspase activation. 5-10 GB-induced cell death also involves Bid/Bax/ Bak-mediated mitochondrial outer membrane permeabilization for the release of the apoptogenic factors cytochrome c, Smac/Diablo, Endo G, HtrA2 and AIF. 1,9-17 We have recently reported that mitochondrial reactive oxygen species (ROS) have a critical role in GB pathway by amplifying apoptogenic factor release, oligonucleosomal DNA fragmentation and lysosomal membrane rupture. 18 Mitochondrial ROS resulted from GB-mediated cleavage of NDUFV1, NDUFS1 and NDUFS2, three subunits of mitochondrial complex I. 18 How GB that does not possess a mitochondrial targeting sequence enters the mitochondria is not known. The mitochondrial nucleoid encodes only for 13 structural proteins, while the rest of the mitochondrial proteome is nuclear-encoded and transported to the mitochondria through a sophisticated protein import machinery. [19][20][21][22][23][24][25][26][27][28] The translocase of the outer mitochondrial membrane (TOM), the entry gate to the mitochondria, 20 passes on the cargos to the sorting and assembly machinery (SAM) complex, to the mitochondrial intermembrane space assembly (MIA) complex and to the translocases of the inner mitochondrial membrane TIM22 or TIM23 complexes for delivery to the outer membrane, the intermembrane space, the inner membrane or the matrix, respectively. [19][20][21][22]25,26,28 Unexpectedly, we found that GB mitochondrial entry is independent of the TOM-TIM23 complexes, but requires instead the Sam50 and Tim22 chann...

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Section: Resultsmentioning

confidence: 99%

Granzyme B enters the mitochondria in a Sam50-, Tim22- and mtHsp70-dependent manner to induce apoptosis

et al. 2017

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“…The small magnitude of Bax-induced cytochrome c release observed in yeast cells, which is consistent with recent reports (Roucou et al, 2000;Gross et al, 2000), as opposed to the larger magnitude of cytochrome c release occurring in isolated mitochondria, could be due to di erences in the amount of Bax acting on the mitochondria or Bax-induced cell death, probably independent of cytochrome c release, that occurs before Bax-mediated increases of mitochondrial membrane permeability in cells. Although yeast cells carry two VDACs, VDAC1 and VDAC2, VDAC2 is known to make only a small contribution to the modulation of membrane permeability to metabolites (Lee et al, 1998). These results indicate that VDAC is required for Bax-induced cytochrome c release in isolated mitochondria as well as in yeast cells.…”

Section: Ant Is Not Required For Bax-induced Apoptotic Mitochondrial mentioning

confidence: 91%

Bax and Bcl-xL independently regulate apoptotic changes of yeast mitochondria that require VDAC but not adenine nucleotide translocator

2000

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Mitochondria play an essential role in apoptosis by releasing apoptogenic molecules such as cytochrome c and AIF, and some caspases, which are all regulated by Bcl-2 family proteins. Pro-apoptotic Bax and Bak have been shown to induce cytochrome c release and loss of membrane potential (Dc) leading to AIF release in the isolated mitochondria. We have previously shown that Bax and Bak open the voltage-dependent anion channel (VDAC) allowing cytochrome c to pass through the channel, and Bcl-x L closes the channel. However, it has been reported that it is adenine nucleotide translocator (ANT) with which Bax/Bcl-x L interacts that modulate the channel activity. Here, we investigated the role of ANT and VDAC in the changes of isolated mitochondria triggered by Bax and by chemicals that induce permeability transition (PT). In rat and yeast mitochondria, Bax did not a ect the ADP/ATP exchange activity of ANT. VDAC-de®cient but not ANT-de®cient yeast mitochondria showed resistance to cytochrome c release, Dc loss, and swelling caused by Bax and PT inducers. Bcl-x L showed similar inhibition of all these changes in ANTde®cient and wild type yeast mitochondria. Furthermore, Bax induces cytochrome c release in wild type yeast cells but not VDAC1-de®cient yeast cells. These data indicate that VDAC, but not ANT, is essential for apoptotic mitochondrial changes. The data also indicate that Bcl-x L and Bax possess an ability to regulate mitochondrial membrane permeability independently of other Bcl-2 family members.

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“…To investigate the hypothesis that the channel induced by ⌬N BCL-xL results from an interaction with VDAC, we tested the actions of ⌬N BCL-xL on isolated mitochondria prepared from wild-type yeast and from yeast that lack the por1 gene, which encodes the VDAC-1 channel (YVDAC1) (45,46).…”

Section: Formation Of Nadh-sensitive Channels By ⌬N Bcl-xl Requires Vmentioning

confidence: 99%

Proapoptotic N-truncated BCL-xL protein activates endogenous mitochondrial channels in living synaptic terminals

Jonas

Hickman

Chachar

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

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Neuronal death is often preceded by functional alterations at nerve terminals. Anti-and proapoptotic BCL-2 family proteins not only regulate the neuronal death pathway but also affect excitability of healthy neurons. We found that exposure of squid stellate ganglia to hypoxia, a death stimulus for neurons, causes a cysteine protease-dependent loss of full-length antiapoptotic BCL-xL, similar to previous findings in mammalian cells. Therefore, to determine the direct effect of the naturally occurring proapoptotic cleavage product of BCL-xL on mitochondria, recombinant N-truncated BCL-xL was applied to mitochondria inside the squid presynaptic terminal and to purified mitochondria isolated from yeast. Ntruncated BCL-xL rapidly induced large multi-conductance channels with a maximal conductance significantly larger than those produced by full-length BCL-xL. This activity required the hydrophobic C terminus and the BH3 domain of BCL-xL. Moreover, N-truncated BCL-xL failed to produce any channel activity when applied to plasma membranes, suggesting that a component of the mitochondrial membrane is necessary for its actions. Consistent with this idea, the large channels induced by N-truncated BCL-xL are inhibited by NADH and require the presence of VDAC, a voltagedependent anion channel present in the outer mitochondrial membrane. These observations suggest that the mitochondrial channels specific to full-length and N-truncated BCL-xL contribute to their opposite effects on synaptic transmission, and are consistent with their opposite effects on the cell death pathway.

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The Role of Yeast VDAC Genes on the Permeability of the Mitochondrial Outer Membrane

Cited by 146 publications

References 24 publications

Granzyme B enters the mitochondria in a Sam50-, Tim22- and mtHsp70-dependent manner to induce apoptosis

Granzyme B enters the mitochondria in a Sam50-, Tim22- and mtHsp70-dependent manner to induce apoptosis

Bax and Bcl-xL independently regulate apoptotic changes of yeast mitochondria that require VDAC but not adenine nucleotide translocator

Proapoptotic N-truncated BCL-xL protein activates endogenous mitochondrial channels in living synaptic terminals

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