scholarly journals The WD40 protein Caf4p is a component of the mitochondrial fission machinery and recruits Dnm1p to mitochondria

2005 ◽  
Vol 170 (2) ◽  
pp. 237-248 ◽  
Author(s):  
Erik E. Griffin ◽  
Johannes Graumann ◽  
David C. Chan
Keyword(s):  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Mitochondrial Outer Membrane ◽  
Dependent Manner ◽  
Related Protein ◽  
Wd40 Repeat ◽  
Mitochondrial Division ◽  
Late Step ◽  
Wd40 Domain ◽  
Molecular Adaptors

The mitochondrial division machinery regulates mitochondrial dynamics and consists of Fis1p, Mdv1p, and Dnm1p. Mitochondrial division relies on the recruitment of the dynamin-related protein Dnm1p to mitochondria. Dnm1p recruitment depends on the mitochondrial outer membrane protein Fis1p. Mdv1p interacts with Fis1p and Dnm1p, but is thought to act at a late step during fission because Mdv1p is dispensable for Dnm1p localization. We identify the WD40 repeat protein Caf4p as a Fis1p-associated protein that localizes to mitochondria in a Fis1p-dependent manner. Caf4p interacts with each component of the fission apparatus: with Fis1p and Mdv1p through its NH2-terminal half and with Dnm1p through its COOH-terminal WD40 domain. We demonstrate that mdv1Δ yeast contain residual mitochondrial fission due to the redundant activity of Caf4p. Moreover, recruitment of Dnm1p to mitochondria is disrupted in mdv1Δ caf4Δ yeast, demonstrating that Mdv1p and Caf4p are molecular adaptors that recruit Dnm1p to mitochondrial fission sites. Our studies support a revised model for assembly of the mitochondrial fission apparatus.

scholarly journals Cardiolipin's propensity for phase transition and its reorganization by dynamin-related protein 1 form a basis for mitochondrial membrane fission

2015 ◽  
Vol 26 (17) ◽  
pp. 3104-3116 ◽  
Author(s):  
Natalia Stepanyants ◽  
Patrick J. Macdonald ◽  
Christopher A. Francy ◽  
Jason A. Mears ◽  
Xin Qi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Mitochondrial Dynamics ◽  
Membrane Surface ◽  
Mitochondrial Fission ◽  
Fluid Phase ◽  
Spatial Density ◽  
Related Protein ◽  
Mitochondrial Division ◽  
Membrane Fission ◽  
Large Gtpases

Cardiolipin (CL) is an atypical, dimeric phospholipid essential for mitochondrial dynamics in eukaryotic cells. Dynamin-related protein 1 (Drp1), a cytosolic member of the dynamin superfamily of large GTPases, interacts with CL and functions to sustain the balance of mitochondrial division and fusion by catalyzing mitochondrial fission. Although recent studies have indicated a role for CL in stimulating Drp1 self-assembly and GTPase activity at the membrane surface, the mechanism by which CL functions in membrane fission, if at all, remains unclear. Here, using a variety of fluorescence spectroscopic and imaging approaches together with model membranes, we demonstrate that Drp1 and CL function cooperatively in effecting membrane constriction toward fission in three distinct steps. These involve 1) the preferential association of Drp1 with CL localized at a high spatial density in the membrane bilayer, 2) the reorganization of unconstrained, fluid-phase CL molecules in concert with Drp1 self-assembly, and 3) the increased propensity of CL to transition from a lamellar, bilayer arrangement to an inverted hexagonal, nonbilayer configuration in the presence of Drp1 and GTP, resulting in the creation of localized membrane constrictions that are primed for fission. Thus we propose that Drp1 and CL function in concert to catalyze mitochondrial division.

scholarly journals Fis1, Mff, MiD49, and MiD51 mediate Drp1 recruitment in mitochondrial fission

2013 ◽  
Vol 24 (5) ◽  
pp. 659-667 ◽  
Author(s):  
Oliver C. Losón ◽  
Zhiyin Song ◽  
Hsiuchen Chen ◽  
David C. Chan
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Outer Membrane Proteins ◽  
Mitochondrial Outer Membrane ◽  
Related Protein ◽  
Immunofluorescence Analysis ◽  
Multiple Receptors ◽  
Mitochondrial Elongation

Several mitochondrial outer membrane proteins—mitochondrial fission protein 1 (Fis1), mitochondrial fission factor (Mff), mitochondrial dynamics proteins of 49 and 51 kDa (MiD49 and MiD51, respectively)—have been proposed to promote mitochondrial fission by recruiting the GTPase dynamin-related protein 1 (Drp1), but fundamental issues remain concerning their function. A recent study supported such a role for Mff but not for Fis1. In addition, it is unclear whether MiD49 and MiD51 activate or inhibit fission, because their overexpression causes extensive mitochondrial elongation. It is also unknown whether these proteins can act in the absence of one another to mediate fission. Using Fis1-null, Mff-null, and Fis1/Mff-null cells, we show that both Fis1 and Mff have roles in mitochondrial fission. Moreover, immunofluorescence analysis of Drp1 suggests that Fis1 and Mff are important for the number and size of Drp1 puncta on mitochondria. Finally, we find that either MiD49 or MiD51 can mediate Drp1 recruitment and mitochondrial fission in the absence of Fis1 and Mff. These results demonstrate that multiple receptors can recruit Drp1 to mediate mitochondrial fission.

scholarly journals Mutations in Fis1 disrupt orderly disposal of defective mitochondria

2014 ◽  
Vol 25 (1) ◽  
pp. 145-159 ◽  
Author(s):  
Qinfang Shen ◽  
Koji Yamano ◽  
Brian P. Head ◽  
Sumihiro Kawajiri ◽  
Jesmine T. M. Cheung ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Couple Stress ◽  
Mitochondrial Fission ◽  
Mitochondrial Outer Membrane ◽  
Related Protein ◽  
Degradation Processes ◽  
Mitochondrial Toxins

Mitochondrial fission is mediated by the dynamin-related protein Drp1 in metazoans. Drp1 is recruited from the cytosol to mitochondria by the mitochondrial outer membrane protein Mff. A second mitochondrial outer membrane protein, named Fis1, was previously proposed as recruitment factor, but Fis1−/− cells have mild or no mitochondrial fission defects. Here we show that Fis1 is nevertheless part of the mitochondrial fission complex in metazoan cells. During the fission cycle, Drp1 first binds to Mff on the surface of mitochondria, followed by entry into a complex that includes Fis1 and endoplasmic reticulum (ER) proteins at the ER–mitochondrial interface. Mutations in Fis1 do not normally affect fission, but they can disrupt downstream degradation events when specific mitochondrial toxins are used to induce fission. The disruptions caused by mutations in Fis1 lead to an accumulation of large LC3 aggregates. We conclude that Fis1 can act in sequence with Mff at the ER–mitochondrial interface to couple stress-induced mitochondrial fission with downstream degradation processes.

scholarly journals Dynamin-related protein 1 deficiency accelerates lipopolysaccharide-induced acute liver injury and inflammation in mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Lixiang Wang ◽  
Xin Li ◽  
Yuki Hanada ◽  
Nao Hasuzawa ◽  
Yoshinori Moriyama ◽  
...  
Keyword(s):  
Liver Disease ◽  
Liver Injury ◽  
Er Stress ◽  
Disease Progression ◽  
Acute Liver Injury ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Mitochondrial Fusion ◽  
Related Protein ◽  
Liver Disease Progression

AbstractMitochondrial fusion and fission, which are strongly related to normal mitochondrial function, are referred to as mitochondrial dynamics. Mitochondrial fusion defects in the liver cause a non-alcoholic steatohepatitis-like phenotype and liver cancer. However, whether mitochondrial fission defect directly impair liver function and stimulate liver disease progression, too, is unclear. Dynamin-related protein 1 (DRP1) is a key factor controlling mitochondrial fission. We hypothesized that DRP1 defects are a causal factor directly involved in liver disease development and stimulate liver disease progression. Drp1 defects directly promoted endoplasmic reticulum (ER) stress, hepatocyte death, and subsequently induced infiltration of inflammatory macrophages. Drp1 deletion increased the expression of numerous genes involved in the immune response and DNA damage in Drp1LiKO mouse primary hepatocytes. We administered lipopolysaccharide (LPS) to liver-specific Drp1-knockout (Drp1LiKO) mice and observed an increased inflammatory cytokine expression in the liver and serum caused by exaggerated ER stress and enhanced inflammasome activation. This study indicates that Drp1 defect-induced mitochondrial dynamics dysfunction directly regulates the fate and function of hepatocytes and enhances LPS-induced acute liver injury in vivo.

scholarly journals A fungal effector targets a heat shock–dynamin protein complex to modulate mitochondrial dynamics and reduce plant immunity

2020 ◽  
Vol 6 (48) ◽  
pp. eabb7719
Author(s):  
Guojuan Xu ◽  
Xionghui Zhong ◽  
Yanlong Shi ◽  
Zhuo Liu ◽  
Nan Jiang ◽  
...  
Keyword(s):  
Transgenic Rice ◽  
Protein Complex ◽  
Fungal Pathogen ◽  
Mitochondrial Dynamics ◽  
Plant Immunity ◽  
Mitochondrial Fission ◽  
Plant Cells ◽  
Related Protein ◽  
Dnaj Protein ◽  
Enhanced Resistance

Mitochondria are essential for animal and plant immunity. Here, we report that the effector MoCDIP4 of the fungal pathogen Magnaporthe oryzae targets the mitochondria-associated OsDjA9-OsDRP1E protein complex to reduce rice immunity. The DnaJ protein OsDjA9 interacts with the dynamin-related protein OsDRP1E and promotes the degradation of OsDRP1E, which functions in mitochondrial fission. By contrast, MoCDIP4 binds OsDjA9 to compete with OsDRP1E, resulting in OsDRP1E accumulation. Knockout of OsDjA9 or overexpression of OsDRP1E or MoCDIP4 in transgenic rice results in shortened mitochondria and enhanced susceptibility to M. oryzae. Overexpression of OsDjA9 or knockout of OsDRP1E in transgenic rice, in contrast, leads to elongated mitochondria and enhanced resistance to M. oryzae. Our study therefore reveals a previously unidentified pathogen-infection strategy in which the pathogen delivers an effector into plant cells to target an HSP40-DRP complex; the targeting leads to the perturbation of mitochondrial dynamics, thereby inhibiting mitochondria-mediated plant immunity.

Inhibition of Drp1-dependent mitochondrial division impairs myogenic differentiation

2013 ◽  
Vol 305 (8) ◽  
pp. R927-R938 ◽  
Author(s):  
Boa Kim ◽  
Ji-Seok Kim ◽  
Yisang Yoon ◽  
Mayra C. Santiago ◽  
Michael D. Brown ◽  
...  
Keyword(s):  
Muscle Development ◽  
Myogenic Differentiation ◽  
Mitochondrial Dynamics ◽  
C2c12 Cells ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Dominant Negative Mutant ◽  
Serum Starvation ◽  
Dependent Manner ◽  
Mitochondrial Division

Mitochondria are dynamic organelles forming a tubular network that is continuously fusing and dividing to control their morphology and functions. Recent literature has shed new light on a potential link between the dynamic behavior of mitochondria and muscle development. In this study, we investigate the role of mitochondrial fission factor dynamin-related protein 1 (Drp1) in myogenic differentiation. We found that differentiation of C2C12 myoblasts induced by serum starvation was accompanied by a gradual increase in Drp1 protein expression (to ∼350% up to 3 days) and a fast reduction of Drp1 phosphorylation at Ser-637 (to ∼30%) resulting in translocation of Drp1 protein from the cytosol to mitochondria. During differentiation, treatment of myoblasts with mitochondrial division inhibitor ( mdivi-1), a specific inhibitor of Drp1 GTPase activity, caused extensive formation of elongated mitochondria, which coincided with increased apoptosis evidenced by both enhanced caspase-3 activity and increased number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells. Furthermore, the mdivi-1-treated myotubes ( day 3 in differentiation media) showed a reduction in mitochondrial DNA content, mitochondrial mass, and membrane potential in a dose-dependent manner indicating defects in mitochondrial biogenesis during myogenic differentiation. Most interestingly, mdivi-1 treatment significantly suppressed myotube formation in both C2C12 cells and primary myoblasts. Likewise, stable overexpression of a dominant negative mutant Drp1 (K38A) dramatically reduced myogenic differentiation. These data suggest that Drp-1-dependent mitochondrial division is a necessary step for successful myogenic differentiation, and perturbation of mitochondrial dynamics hinders normal mitochondrial adaptations during muscle development. Therefore, in the present study, we report a novel physiological role of mitochondrial dynamics in myogenic differentiation.

scholarly journals Parkin-mediated ubiquitination contributes to the constitutive turnover of mitochondrial fission factor (Mff)

2019 ◽  
Author(s):  
Laura Lee ◽  
Richard Seager ◽  
Kevin A. Wilkinson ◽  
Jeremy M. Henley
Keyword(s):  
Membrane Protein ◽  
Ubiquitin Ligase ◽  
Mitochondrial Membrane ◽  
Mitochondrial Fission ◽  
Protein Composition ◽  
Mitochondrial Outer Membrane ◽  
Dependent Manner ◽  
Mitochondrial Network ◽  
Functionally Impaired ◽  
Mitochondrial Membrane Protein

AbstractThe mitochondrial outer membrane protein Mitochondrial Fission Factor (Mff) plays a key role in both physiological and pathological fission. It is well established that in stressed or functionally impaired mitochondria the PINK1 recruits the ubiquitin ligase Parkin which ubiquitinates Mff to facilitate the removal of defective mitochondria and maintain the integrity mitochondrial network. Here we show that, in addition to this clearance pathway, Parkin also ubiquitinates Mff in a PINK1-dependent manner under basal, non-stressed conditions to regulate constitutive Mff turnover. We further show that removing Parkin with shRNA knockdown does not completely prevent Mff ubiquitination under these conditions indicating that at least one other ubiquitin ligase contributes to Mff proteostasis. These data demonstrate that Parkin plays a role in physiological maintenance of mitochondrial membrane protein composition in healthy mitochondria through constitutive low-level activation.

scholarly journals Role of GTPase-Dependent Mitochondrial Dynamins in Heart Diseases

2021 ◽  
Vol 8 ◽  
Author(s):  
Jiangen Liu ◽  
Xianjing Song ◽  
Youyou Yan ◽  
Bin Liu
Keyword(s):  
Cell Function ◽  
Morphological Changes ◽  
Heart Function ◽  
Mitochondrial Dynamics ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Mitochondrial Fusion ◽  
Dependent Manner

Heart function maintenance requires a large amount of energy, which is supplied by the mitochondria. In addition to providing energy to cardiomyocytes, mitochondria also play an important role in maintaining cell function and homeostasis. Although adult cardiomyocyte mitochondria appear as independent, low-static organelles, morphological changes have been observed in cardiomyocyte mitochondria under stress or pathological conditions. Indeed, cardiac mitochondrial fission and fusion are involved in the occurrence and development of heart diseases. As mitochondrial fission and fusion are primarily regulated by mitochondrial dynamins in a GTPase-dependent manner, GTPase-dependent mitochondrial fusion (MFN1, MFN2, and OPA1) and fission (DRP1) proteins, which are abundant in the adult heart, can also be regulated in heart diseases. In fact, these dynamic proteins have been shown to play important roles in specific diseases, including ischemia-reperfusion injury, heart failure, and metabolic cardiomyopathy. This article reviews the role of GTPase-dependent mitochondrial fusion and fission protein-mediated mitochondrial dynamics in the occurrence and development of heart diseases.

Abstract 393: MCL-1 Promotes Survival and Influences Mitochondrial Dynamics in Cardiac Myocytes

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Alexandra G Moyzis ◽  
Robert L Thomas ◽  
Jennifer Kuo ◽  
Åsa B Gustafsson
Keyword(s):  
Cell Death ◽  
Cardiac Myocytes ◽  
Apoptotic Cell ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Apoptotic Cell Death ◽  
Mitochondrial Fusion ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Morphology ◽  
Rapid Degradation

The BCL-2 family proteins are important regulators of mitochondrial structure and integrity. MCL-1 is an anti-apoptotic BCL-2 protein that is highly expressed in the myocardium compared to the other anti-apoptotic proteins BCL-2 and BCL-X L. Recently, we reported that MCL-1 is essential for myocardial homeostasis. Cardiac-specific deletion of MCL-1 in mice led to rapid mitochondrial dysfunction, hypertrophy, and lethal cardiomyopathy. Surprisingly, MCL-1 deficient myocytes did not undergo apoptotic cell death. Instead, the cells displayed signs of mitochondrial deterioration and necrotic cell death, suggesting that MCL-1 has an additional role in maintaining mitochondrial function in cardiac myocytes. Similarly, deletion of MCL-1 in fibroblasts caused rapid mitochondrial fragmentation followed by cell death at 72 hours. Interestingly, the MCL-1 deficient fibroblasts retained cytochrome c in the mitochondria , confirming that the cells were not undergoing apoptotic cell death. We have also identified that MCL-1 localizes to the mitochondrial outer membrane (OM) and the matrix in the myocardium and that the two forms respond differently to stress. MCL-1 OM was rapidly degraded after myocardial infarction or fasting, whereas MCL-1 Matrix levels were maintained. Similarly, starvation of MEFs resulted in rapid degradation of MCL-1 OM , whereas MCL-1 Matrix showed delayed degradation. Treatment with the mitochondrial uncoupler FCCP led to rapid degradation of both forms. This suggests that the susceptibility to degradation is dependent on its localization and the nature of the stress. Our data also suggests that these two forms perform distinct functions in regulating mitochondrial morphology and survival. Overexpression of MCL-1 Matrix promoted mitochondrial fusion in fibroblasts under baseline conditions and protected cells against FCCP-mediated mitochondrial fission and clearance by autophagosomes. Thus, our data suggest that MCL-1 exists in two separate locations where it performs different functions. MCL-1 Matrix promotes mitochondrial fusion, which protects cells against excessive mitochondrial clearance during unfavorable conditions.

scholarly journals Expression, purification, crystallization and preliminary crystallographic study of the cytoplasmic domain of the mitochondrial dynamics protein MiD51

2014 ◽  
Vol 70 (5) ◽  
pp. 596-599
Author(s):  
Jun Ma ◽  
Fei Sun
Keyword(s):  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Cytoplasmic Domain ◽  
Mitochondrial Outer Membrane ◽  
X Ray Diffraction ◽  
Data Set ◽  
X Ray ◽  
Cell Parameters ◽  
Physiological Processes ◽  
Crystallographic Study

Mitochondria play central roles in many cellular and physiological processes. They are highly dynamic organelles and continually undergo fusion and fission. Mitochondrial dynamics protein 51 kDa (MiD51), an integral mitochondrial outer membrane protein, recruits dynamin-related protein 1 (Drp1; a mitochondrial fission protein) to mitochondria and facilitates Drp1-directed mitochondrial fission. In this study, the cytoplasmic domain of MiD51 was overexpressed inEscherichia coli, purified and crystallized. An X-ray diffraction data set was collected to a resolution of 3.1 Å and the crystal belonged to space groupP41212, with unit-cell parametersa=b= 90.1,c= 124.7 Å, α = β = γ = 90°. The asymmetric unit had the highest probability of containing one molecule, with a Matthews coefficient of 3.32 Å3 Da−1and a solvent content of 63.0%.

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