<i>Drosophila</i> MIC60/mitofilin conducts dual roles in mitochondrial motility and crista structure

Tsai, Patricia S.; Papakyrikos, Amanda M.; Hsieh, Chung-Han; Wang, Xinnan

doi:10.1091/mbc.e17-03-0177

Cited by 28 publications

(33 citation statements)

References 44 publications

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“… 25 ). Moreover, Mic60, a main subunit of the MICOS complex in mammals, is reportedly found in purified HeLa mtDNA 26 , and endogenous human Miro1 and Mic60 were found to be associated in the same complex 27 , 28 . Mic60 contains a transmembrane domain that spans the inner mitochondrial membrane with the bulk of the protein protruding into the intermembrane space 29 .…”

Section: Resultsmentioning

confidence: 99%

ER-mitochondria contacts promote mtDNA nucleoids active transportation via mitochondrial dynamic tubulation

et al. 2020

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A human cell contains hundreds to thousands of mitochondrial DNA (mtDNA) packaged into nucleoids. Currently, the segregation and allocation of nucleoids are thought to be passively determined by mitochondrial fusion and division. Here we provide evidence, using live-cell super-resolution imaging, that nucleoids can be actively transported via KIF5B-driven mitochondrial dynamic tubulation (MDT) activities that predominantly occur at the ER-mitochondria contact sites (EMCS). We further demonstrate that a mitochondrial inner membrane protein complex MICOS links nucleoids to Miro1, a KIF5B receptor on mitochondria, at the EMCS. We show that such active transportation is a mechanism essential for the proper distribution of nucleoids in the peripheral zone of the cell. Together, our work identifies an active transportation mechanism of nucleoids, with EMCS serving as a key platform for the interplay of nucleoids, MICOS, Miro1, and KIF5B to coordinate nucleoids segregation and transportation.

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Section: Resultsmentioning

confidence: 99%

ER-mitochondria contacts promote mtDNA nucleoids active transportation via mitochondrial dynamic tubulation

et al. 2020

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“…The Drosophila homolog, MIC60, has been shown to regulate mitochondrial dynamics. Mutant flies lacking MIC60 show decreased Miro protein levels and altered mitochondrial dynamics (Tsai, Papakyrikos, Hsieh, & Wang, ). VDAC2 are mitochondrial outer membrane porins involved in ATP homeostasis (Colombini, ; Saks et al, ), and in some instances may be regulated by interaction with microtubules (Ramos, Hughes, & Perry, ).…”

Section: Resultsmentioning

confidence: 99%

The MyMOMA domain of MYO19 encodes for distinct Miro‐dependent and Miro‐independent mechanisms of interaction with mitochondrial membranes

et al. 2019

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MYO19 interacts with mitochondria through a C‐terminal membrane association domain (MyMOMA). Specific mechanisms for localization of MYO19 to mitochondria are poorly understood. Using promiscuous biotinylation data in combination with existing affinity‐capture databases, we have identified a number of putative MYO19‐interacting proteins. We chose to explore the interaction between MYO19 and the mitochondrial GTPase Miro2 by expressing mchr‐Miro2 in combination with GFP‐tagged fragments of the MyMOMA domain and assaying for recruitment of MYO19‐GFP to mitochondria. Coexpression of MYO19898‐970‐GFP with mchr‐Miro2 enhanced MYO19898‐970‐GFP localization to mitochondria. Mislocalizing Miro2 to filopodial tips or the cytosolic face of the nuclear envelope did not recruit MYO19898‐970‐GFP to either location. To address the kinetics of the Miro2/MYO19 interaction, we used FRAP analysis and permeabilization‐activated reduction in fluorescence analysis. MyMOMA constructs containing a putative membrane‐insertion motif but lacking the Miro2‐interacting region displayed slow exchange kinetics. MYO19898‐970‐GFP, which does not include the membrane‐insertion motif, displayed rapid exchange kinetics, suggesting that MYO19 interacting with Miro2 has higher mobility than MYO19 inserted into the mitochondrial outer membrane. Mutation of well‐conserved, charged residues within MYO19 or within the switch I and II regions of Miro2 abolished the enhancement of MYO19898‐970‐GFP localization in cells ectopically expressing mchr‐Miro2. Additionally, expressing mutant versions of Miro2 thought to represent particular nucleotide states indicated that the enhancement of MYO19898‐970‐GFP localization is dependent on Miro2 nucleotide state. Taken together, these data suggest that membrane‐inserted MYO19 is part of a larger complex, and that Miro2 plays a role in integration of actin‐ and microtubule‐based mitochondrial activities.

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“…The Drosophila homolog, MIC60, has been shown to regulate mitochondrial dynamics. Mutant flies lacking MIC60 show decreased Miro protein levels and altered mitochondrial dynamics [Tsai et al 2017]. VDAC2 are mitochondrial outer membrane porins involved in ATP homeostasis [Colombini 2012;Saks et al 1995], and in some instances may be regulated by interaction with microtubules [Ramos et al 2019].…”

Section: Resultsmentioning

confidence: 99%

The MyMOMA domain of MYO19 encodes for distinct Miro-dependent and Miro-independent mechanisms of interaction with mitochondrial membranes

Bocanegra

Fujita

Melton

et al. 2019

Preprint

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for critical reading and discussions related to this manuscript. Hypotheses and experiments in this study were conceived by OAQ. Experiments were performed by JLB, BMF, NRM, JMC, ELS, TYT, and OAQ.Data analysis and manuscript preparation were completed by JLB, BMF, NRM, JMC, TYT, MBM, and OAQ. Except for the proteomics analysis, all experiments for the initial submission were completed during the 10-week 2018 summer research session at University of Richmond. We would also like to that Edward Salmon for his example and inspiration.3 Abstract MYO19 interacts with mitochondria through a C-terminal membrane association domain (MyMOMA).The specific mechanisms for localization of MYO19 to mitochondria are poorly understood. Using new promiscuous biotinylation data in combination with existing affinity-capture databases, we have identified a number of putative MYO19-interacting proteins. We chose to further explore the interaction between MYO19 and the mitochondrial GTPase Miro2 by expressing mchr-Miro2 in combination with GFP-tagged fragments of the MyMOMA domain and assaying for recruitment of MYO19-GFP to mitochondria. Co-expression of MYO19 898-970 -GFP with mchr-Miro2 enhanced MYO19 898-970 -GFP localization to mitochondria. Mislocalizing Miro2 to filopodial tips or the cytosolic face of the nuclear envelope did not recruit MYO19 898-970 -GFP to either location. To address the kinetics of the Miro2/MYO19 interaction, we used FRAP analysis and permeabilization-activated reduction in fluorescence (PARF) analysis. MyMOMA constructs containing a putative membrane insertion motif but lacking the Miro2-interacting region displayed slow exchange kinetics. MYO19 898-970 -GFP, which does not include the membrane-insertion motif, displayed rapid exchange kinetics, suggesting that the MYO19 interacting with Miro2 has higher mobility than MYO19 inserted into the mitochondrial outer membrane. Mutation of well-conserved, charged residues within MYO19 or within the switch I and II regions of Miro2 abolished the enhancement of MYO19 898-970 -GFP localization in cells ectopically expressing mchr-Miro2. Additionally, expressing mutant versions of Miro2 thought to represent particular nucleotide states indicated that the enhancement of MYO19 898-970 -GFP localization is dependent on Miro2 nucleotide state. Taken together, these data suggest that membrane-inserted MYO19 is part of a larger complex, and that Miro2 plays a role in integration of actin-and microtubulebased mitochondrial activities.

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Drosophila MIC60/mitofilin conducts dual roles in mitochondrial motility and crista structure

Cited by 28 publications

References 44 publications

ER-mitochondria contacts promote mtDNA nucleoids active transportation via mitochondrial dynamic tubulation

ER-mitochondria contacts promote mtDNA nucleoids active transportation via mitochondrial dynamic tubulation

The MyMOMA domain of MYO19 encodes for distinct Miro‐dependent and Miro‐independent mechanisms of interaction with mitochondrial membranes

The MyMOMA domain of MYO19 encodes for distinct Miro-dependent and Miro-independent mechanisms of interaction with mitochondrial membranes

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