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Cells Aug 2022Endocytosis is a fundamental mechanism by which cells perform housekeeping functions. It occurs via a variety of mechanisms and involves many regulatory proteins. The... (Review)
Review
Endocytosis is a fundamental mechanism by which cells perform housekeeping functions. It occurs via a variety of mechanisms and involves many regulatory proteins. The GTPase dynamin acts as a "molecular scissor" to form endocytic vesicles and is a critical regulator among the proteins involved in endocytosis. Some GTPases (e.g., Cdc42, arf6, RhoA), membrane proteins (e.g., flotillins, tetraspanins), and secondary messengers (e.g., calcium) mediate dynamin-independent endocytosis. These pathways may be convergent, as multiple pathways exist in a single cell. However, what determines the specific path of endocytosis is complex and challenging to comprehend. This review summarizes the mechanisms of dynamin-independent endocytosis, the involvement of microRNAs, and factors that contribute to the cellular decision about the specific route of endocytosis.
Topics: Dynamins; Endocytosis; Transport Vesicles
PubMed: 36010634
DOI: 10.3390/cells11162557 -
The Journal of Biological Chemistry Sep 2010The interferon-inducible MxA GTPase is a key mediator of cell-autonomous innate immunity against a broad range of viruses such as influenza and bunyaviruses. MxA shares... (Review)
Review
The interferon-inducible MxA GTPase is a key mediator of cell-autonomous innate immunity against a broad range of viruses such as influenza and bunyaviruses. MxA shares a similar domain structure with the dynamin superfamily of mechanochemical enzymes, including an N-terminal GTPase domain, a central middle domain, and a C-terminal GTPase effector domain. Recently, crystal structures of a GTPase domain dimer of dynamin 1 and of the oligomerized stalk of MxA (built by the middle and GTPase effector domains) were determined. These data provide exciting insights into the architecture and antiviral function of the MxA oligomer. Moreover, the structural knowledge paves the way for the development of novel antiviral drugs against influenza and other highly pathogenic viruses.
Topics: Animals; Antiviral Agents; Crystallography, X-Ray; Dynamins; GTP-Binding Proteins; Humans; Immunity, Innate; Influenza A virus; Influenza, Human; Myxovirus Resistance Proteins; Protein Multimerization; Protein Structure, Tertiary; Structural Homology, Protein; Structure-Activity Relationship
PubMed: 20538602
DOI: 10.1074/jbc.R110.145839 -
Nature Communications Jul 2023The large cytosolic GTPase, dynamin-related protein 1 (Drp1), mediates both physiological and pathological mitochondrial fission. Cell stress triggers Drp1 binding to...
The large cytosolic GTPase, dynamin-related protein 1 (Drp1), mediates both physiological and pathological mitochondrial fission. Cell stress triggers Drp1 binding to mitochondrial Fis1 and subsequently, mitochondrial fragmentation, ROS production, metabolic collapse, and cell death. Because Drp1 also mediates physiological fission by binding to mitochondrial Mff, therapeutics that inhibit pathological fission should spare physiological mitochondrial fission. P110, a peptide inhibitor of Drp1-Fis1 interaction, reduces pathology in numerous models of neurodegeneration, ischemia, and sepsis without blocking the physiological functions of Drp1. Since peptides have pharmacokinetic limitations, we set out to identify small molecules that mimic P110's benefit. We map the P110-binding site to a switch I-adjacent grove (SWAG) on Drp1. Screening for SWAG-binding small molecules identifies SC9, which mimics P110's benefits in cells and a mouse model of endotoxemia. We suggest that the SWAG-binding small molecules discovered in this study may reduce the burden of Drp1-mediated pathologies and potentially pathologies associated with other members of the GTPase family.
Topics: Animals; Mice; Allosteric Site; Disease Models, Animal; Dynamins; GTP Phosphohydrolases; Mitochondria; Mitochondrial Dynamics; Mitochondrial Proteins
PubMed: 37468472
DOI: 10.1038/s41467-023-40043-0 -
Biochimica Et Biophysica Acta Jun 2015The Activity-regulated cytoskeleton-associated protein, Arc, is an immediate-early gene product implicated in various forms of synaptic plasticity. Arc promotes...
BACKGROUND
The Activity-regulated cytoskeleton-associated protein, Arc, is an immediate-early gene product implicated in various forms of synaptic plasticity. Arc promotes endocytosis of AMPA type glutamate receptors and regulates cytoskeletal assembly in neuronal dendrites. Its role in endocytosis may be mediated by its reported interaction with dynamin 2, a 100 kDa GTPase that polymerizes around the necks of budding vesicles and catalyzes membrane scission.
METHODS
Enzymatic and turbidity assays are used in this study to monitor effects of Arc on dynamin activity and polymerization. Arc oligomerization is measured using a combination of approaches, including size exclusion chromatography, sedimentation analysis, dynamic light scattering, fluorescence correlation spectroscopy, and electron microscopy.
RESULTS
We present evidence that bacterially-expressed His6-Arc facilitates the polymerization of dynamin 2 and stimulates its GTPase activity under physiologic conditions (37°C and 100mM NaCl). At lower ionic strength Arc also stabilizes pre-formed dynamin 2 polymers against GTP-dependent disassembly, thereby prolonging assembly-dependent GTP hydrolysis catalyzed by dynamin 2. Arc also increases the GTPase activity of dynamin 3, an isoform of implicated in dendrite remodeling, but does not affect the activity of dynamin 1, a neuron-specific isoform involved in synaptic vesicle recycling. We further show in this study that Arc (either His6-tagged or untagged) has a tendency to form large soluble oligomers, which may function as a scaffold for dynamin assembly and activation.
CONCLUSIONS AND GENERAL SIGNIFICANCE
The ability of Arc to enhance dynamin polymerization and GTPase activation may provide a mechanism to explain Arc-mediated endocytosis of AMPA receptors and the accompanying effects on synaptic plasticity.
Topics: Animals; Cytoskeletal Proteins; Dynamin I; Dynamin II; Dynamin III; Dynamins; Enzyme Activation; Guanosine Triphosphate; Histidine; Humans; Hydrolysis; Mice; Nerve Tissue Proteins; Oligopeptides; Polymerization; Rats; Recombinant Fusion Proteins; Sodium Chloride; Temperature; Time Factors
PubMed: 25783003
DOI: 10.1016/j.bbagen.2015.03.002 -
Cell Communication and Signaling : CCS Apr 2015Dynamin is a GTPase protein that is essential for membrane fission during clathrin-mediated endocytosis in eukaryotic cells. Dynasore is a GTPase inhibitor that rapidly... (Review)
Review
Dynamin is a GTPase protein that is essential for membrane fission during clathrin-mediated endocytosis in eukaryotic cells. Dynasore is a GTPase inhibitor that rapidly and reversibly inhibits dynamin activity, which prevents endocytosis. However, comparison between cells treated with dynasore and RNA interference of genes encoding dynamin, reveals evidence that dynasore reduces labile cholesterol in the plasma membrane, and disrupts lipid raft organization, in a dynamin-independent manner. To explore the role of dynamin it is important to use multiple dynamin inhibitors, alongside the use of dynamin mutants and RNA interference targeting genes encoding dynamin. On the other hand, dynasore provides an interesting tool to explore the regulation of cholesterol in plasma membranes.
Topics: Animals; Cell Membrane; Cholesterol; Dynamins; Enzyme Inhibitors; Humans; Hydrazones
PubMed: 25889964
DOI: 10.1186/s12964-015-0102-1 -
Trends in Cell Biology Mar 2019Dynamin superfamily proteins (DSPs) mediate membrane fission and fusion necessary for endocytosis, organelle biogenesis and maintenance, as well as for bacterial... (Review)
Review
Dynamin superfamily proteins (DSPs) mediate membrane fission and fusion necessary for endocytosis, organelle biogenesis and maintenance, as well as for bacterial cytokinesis. They also function in the innate immune response to pathogens and in organizing the cytoskeleton. In this review, we summarize the current understanding of the molecular mechanism of DSPs, with emphasis on the structural basis of function. Studies from the past decade on the structure and mechanism of DSPs enable comparative analysis of shared mechanisms and unique features of this protein family.
Topics: Animals; Dynamins; Humans; Protein Conformation
PubMed: 30527453
DOI: 10.1016/j.tcb.2018.11.003 -
Redox Biology Dec 2022Hydrogen sulfide (HS), produced by cystathionine γ lyase (CSE), is an important endogenous gasotransmitter to maintain heart function. However, the molecular mechanism...
Hydrogen sulfide (HS), produced by cystathionine γ lyase (CSE), is an important endogenous gasotransmitter to maintain heart function. However, the molecular mechanism for how HS influences the mitochondrial morphology during heart failure remains poorly understood. Here, we found that CSE/HS pathway mediated cardiac function and mitochondrial morphology through regulating dynamin related protein 1 (Drp1) activity and translocation. Mechanistically, elevation of HS levels by CSE overexpression declined protein level, phosphorylation (Ser 616), oligomerization and GTPase activity of Drp1 by S-sulfhydration in mouse hearts. Interestingly, Drp1 S-sulfhydration directly competed with S-nitrosylation by nitric oxide at the specific cysteine 607. The non-S-sulfhydration of Drp1 mutation (C607A) attenuated the regulatory effect of HS on Drp1 activation, mitochondrial fission and heart function. Moreover, the non-canonical role of Drp1 mediated isoprenaline-induced mitochondrial dysfunction and cardiomyocyte death through interaction with voltage-dependent anion channel 1. These results uncover that a novel mechanism that HS S-sulfhydrated Drp1 at cysteine 607 to prevent heart failure through modulating its activity and mitochondrial translocation. Our findings also provide initial evidence demonstrating that Drp1 may be a critical regulator as well as an effective strategy for heart dysfunction.
Topics: Mice; Animals; Cystathionine gamma-Lyase; Cysteine; Hydrogen Sulfide; Dynamins; Heart Failure
PubMed: 36327794
DOI: 10.1016/j.redox.2022.102519 -
Current Biology : CB Dec 2002Cytokinesis involves the concerted efforts of the microtubule and actin cytoskeletons as well as vesicle trafficking and membrane remodeling to form the cleavage furrow...
Cytokinesis involves the concerted efforts of the microtubule and actin cytoskeletons as well as vesicle trafficking and membrane remodeling to form the cleavage furrow and complete daughter cell separation. The exact mechanisms that support membrane remodeling during cytokinesis remain largely undefined. In this study, we report that the large GTPase dynamin, a protein involved in membrane tubulation and vesiculation, is essential for successful cytokinesis. Using biochemical and morphological methods, we demonstrate that dynamin localizes to the spindle midzone and the subsequent intercellular bridge in mammalian cells and is also enriched in spindle midbody extracts. In Caenorhabditis elegans, dynamin localized to newly formed cleavage furrow membranes and accumulated at the midbody of dividing embryos in a manner similar to dynamin localization in mammalian cells. Further, dynamin function appears necessary for cytokinesis, as C. elegans embryos from a dyn-1 ts strain, as well as dynamin RNAi-treated embryos, showed a marked defect in the late stages of cytokinesis. These findings indicate that, during mitosis, conventional dynamin is recruited to the spindle midzone and the subsequent intercellular bridge, where it plays an essential role in the final separation of dividing cells.
Topics: Animals; Caenorhabditis elegans; Cell Division; Cell Line; Dynamins; Embryo, Nonmammalian; HeLa Cells; Humans; Liver; Microscopy, Immunoelectron; Microtubules; Mutation; Paclitaxel; RNA Interference; Rats; Spindle Apparatus; Temperature
PubMed: 12498685
DOI: 10.1016/s0960-9822(02)01390-8 -
The EMBO Journal Nov 2016The large GTPase dynamin is the first protein shown to catalyze membrane fission. Dynamin and its related proteins are essential to many cell functions, from endocytosis... (Review)
Review
The large GTPase dynamin is the first protein shown to catalyze membrane fission. Dynamin and its related proteins are essential to many cell functions, from endocytosis to organelle division and fusion, and it plays a critical role in many physiological functions such as synaptic transmission and muscle contraction. Research of the past three decades has focused on understanding how dynamin works. In this review, we present the basis for an emerging consensus on how dynamin functions. Three properties of dynamin are strongly supported by experimental data: first, dynamin oligomerizes into a helical polymer; second, dynamin oligomer constricts in the presence of GTP; and third, dynamin catalyzes membrane fission upon GTP hydrolysis. We present the two current models for fission, essentially diverging in how GTP energy is spent. We further discuss how future research might solve the remaining open questions presently under discussion.
Topics: Animals; Cell Membrane; Dynamins; Guanosine Triphosphate; Humans
PubMed: 27670760
DOI: 10.15252/embj.201694613 -
Cancer Metastasis Reviews Dec 2023Metastatic progression is regulated by metastasis promoter and suppressor genes. NME1, the prototypic and first described metastasis suppressor gene, encodes a... (Review)
Review
Metastatic progression is regulated by metastasis promoter and suppressor genes. NME1, the prototypic and first described metastasis suppressor gene, encodes a nucleoside diphosphate kinase (NDPK) involved in nucleotide metabolism; two related family members, NME2 and NME4, are also reported as metastasis suppressors. These proteins physically interact with members of the GTPase dynamin family, which have key functions in membrane fission and fusion reactions necessary for endocytosis and mitochondrial dynamics. Evidence supports a model in which NDPKs provide GTP to dynamins to maintain a high local GTP concentration for optimal dynamin function. NME1 and NME2 are cytosolic enzymes that provide GTP to dynamins at the plasma membrane, which drive endocytosis, suggesting that these NMEs are necessary to attenuate signaling by receptors on the cell surface. Disruption of NDPK activity in NME-deficient tumors may thus drive metastasis by prolonging signaling. NME4 is a mitochondrial enzyme that interacts with the dynamin OPA1 at the mitochondria inner membrane to drive inner membrane fusion and maintain a fused mitochondrial network. This function is consistent with the current view that mitochondrial fusion inhibits the metastatic potential of tumor cells whereas mitochondrial fission promotes metastasis progression. The roles of NME family members in dynamin-mediated endocytosis and mitochondrial dynamics and the intimate link between these processes and metastasis provide a new framework to understand the metastasis suppressor functions of NME proteins.
Topics: Humans; NM23 Nucleoside Diphosphate Kinases; Dynamins; Neoplasms; Cell Membrane; Guanosine Triphosphate
PubMed: 37353690
DOI: 10.1007/s10555-023-10118-x