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European Journal of Cell Biology Jul 2014Dynamin is a GTPase mechanoenzyme most noted for its role in vesicle scission during endocytosis, and belongs to the dynamin family proteins. The dynamin family consists... (Review)
Review
Dynamin is a GTPase mechanoenzyme most noted for its role in vesicle scission during endocytosis, and belongs to the dynamin family proteins. The dynamin family consists of classical dynamins and dynamin-like proteins (DLPs). Due to structural and functional similarities DLPs are thought to carry out membrane tubulation and scission in a similar manner to dynamin. Here, we discuss the newly emerging roles for DLPs, which include vacuole fission and fusion, peroxisome maintenance, endocytosis and intracellular trafficking. Specific focus is given to the role of DLPs in the budding yeast Saccharomyces cerevisiae because the diverse function of DLPs has been well characterized in this organism. Recent insights into DLPs may provide a better understanding of mammalian dynamin and its associated diseases.
Topics: Dynamins; Endocytosis; Humans; Intracellular Membranes; Mitochondria; Organelles; Peroxisomes; Protein Transport; Saccharomyces cerevisiae
PubMed: 24954468
DOI: 10.1016/j.ejcb.2014.05.002 -
Cells Aug 2019The purpose of this article is to highlight the role of dynamin-related protein 1 (Drp1) in abnormal mitochondrial dynamics, mitochondrial fragmentation,... (Review)
Review
The purpose of this article is to highlight the role of dynamin-related protein 1 (Drp1) in abnormal mitochondrial dynamics, mitochondrial fragmentation, autophagy/mitophagy, and neuronal damage in Alzheimer's disease (AD) and other neurological diseases, including Parkinson's, Huntington's, amyotrophic lateral sclerosis, multiple sclerosis, diabetes, and obesity. Dynamin-related protein 1 is one of the evolutionarily highly conserved large family of GTPase proteins. Drp1 is critical for mitochondrial division, size, shape, and distribution throughout the neuron, from cell body to axons, dendrites, and nerve terminals. Several decades of intense research from several groups revealed that Drp1 is enriched at neuronal terminals and involved in synapse formation and synaptic sprouting. Different phosphorylated forms of Drp1 acts as both increased fragmentation and/or increased fusion of mitochondria. Increased levels of Drp1 were found in diseased states and caused excessive fragmentation of mitochondria, leading to mitochondrial dysfunction and neuronal damage. In the last two decades, several Drp1 inhibitors have been developed, including Mdivi-1, Dynasore, P110, and DDQ and their beneficial effects tested using cell cultures and mouse models of neurodegenerative diseases. Recent research using genetic crossing studies revealed that a partial reduction of Drp1 is protective against mutant protein(s)-induced mitochondrial and synaptic toxicities. Based on findings from cell cultures, mouse models and postmortem brains of AD and other neurodegenerative disease, we cautiously conclude that reduced Drp1 is a promising therapeutic target for AD and other neurological diseases.
Topics: Animals; Dynamins; Humans; Mice; Mitochondria; Neurodegenerative Diseases
PubMed: 31450774
DOI: 10.3390/cells8090961 -
Current Opinion in Cell Biology Aug 1998Dynamin's role in clathrin-mediated endocytosis is now well established. Here we review new evidence from the past two years for the function of dynamin and related... (Review)
Review
Dynamin's role in clathrin-mediated endocytosis is now well established. Here we review new evidence from the past two years for the function of dynamin and related GTPases in other Intracellular trafficking events. We then summarize current information on the domain structure and function of this multidomain GTPase. Finally, we describe dynamin partners and their function in the context of clathrin-mediated endocytosis.
Topics: Alternative Splicing; Amino Acid Sequence; Animals; Binding Sites; Dynamins; Endocytosis; GTP Phosphohydrolases; Hydrogen-Ion Concentration; Intracellular Membranes; Molecular Sequence Data; Phosphatidylinositols; Proteins
PubMed: 9719872
DOI: 10.1016/s0955-0674(98)80066-5 -
Science (New York, N.Y.) Aug 1994Dynamin I is a nerve terminal phosphoprotein with intrinsic guanosine triphosphatase (GTPase) activity that is required for endocytosis. Upon depolarization and synaptic...
Dynamin I is a nerve terminal phosphoprotein with intrinsic guanosine triphosphatase (GTPase) activity that is required for endocytosis. Upon depolarization and synaptic vesicle recycling, dynamin I undergoes a rapid dephosphorylation. Dynamin I was found to be a specific high-affinity substrate for calcineurin in vitro. At low concentrations, calcineurin dephosphorylated dynamin I that had been phosphorylated by protein kinase C. The dephosphorylation inhibited dynamin I GTPase activity in vitro and after depolarization of nerve terminals. The effect in nerve terminals was prevented by the calcineurin inhibitor cyclosporin A. This suggests that in nerve terminals, calcineurin serves as a Ca(2+)-sensitive switch for depolarization-evoked synaptic vesicle recycling.
Topics: Animals; Calcineurin; Calcium; Calmodulin-Binding Proteins; Cyclosporine; Dynamin I; Dynamins; Endocytosis; GTP Phosphohydrolases; Nerve Endings; Phosphoprotein Phosphatases; Phosphorylation; Rats; Synaptic Vesicles; Synaptosomes
PubMed: 8052858
DOI: 10.1126/science.8052858 -
Nature Communications Jan 2024The mechanochemical GTPase dynamin-related protein 1 (Drp1) catalyzes mitochondrial and peroxisomal fission, but the regulatory mechanisms remain ambiguous. Here we find...
The mechanochemical GTPase dynamin-related protein 1 (Drp1) catalyzes mitochondrial and peroxisomal fission, but the regulatory mechanisms remain ambiguous. Here we find that a conserved, intrinsically disordered, six-residue Short Linear Motif at the extreme Drp1 C-terminus, named CT-SLiM, constitutes a critical allosteric site that controls Drp1 structure and function in vitro and in vivo. Extension of the CT-SLiM by non-native residues, or its interaction with the protein partner GIPC-1, constrains Drp1 subunit conformational dynamics, alters self-assembly properties, and limits cooperative GTP hydrolysis, surprisingly leading to the fission of model membranes in vitro. In vivo, the involvement of the native CT-SLiM is critical for productive mitochondrial and peroxisomal fission, as both deletion and non-native extension of the CT-SLiM severely impair their progression. Thus, contrary to prevailing models, Drp1-catalyzed membrane fission relies on allosteric communication mediated by the CT-SLiM, deceleration of GTPase activity, and coupled changes in subunit architecture and assembly-disassembly dynamics.
Topics: Dynamins; GTP Phosphohydrolases; Mitochondria; Hydrolysis; Membrane Fusion; Mitochondrial Dynamics; Mitochondrial Proteins
PubMed: 38168038
DOI: 10.1038/s41467-023-44413-6 -
FASEB Journal : Official Publication of... Dec 1999Dynamin is a 100-kDa GTPase that has been implicated in endocytosis. To extend our understanding of its cellular functions, we have microinjected specific... (Review)
Review
Dynamin is a 100-kDa GTPase that has been implicated in endocytosis. To extend our understanding of its cellular functions, we have microinjected specific affinity-purified anti-dynamin antibodies into cultured mammalian epithelial cells. Using this approach, dynamin function can be inhibited specifically and rapidly in single cells. Effects of microinjected inhibitory antibodies on distinct endocytic processes and plasmalemmal morphology were then assayed by fluorescence microscopy (FM) and ultrastructural analysis. Micro-injected antibodies inhibit the clathrin-mediated endocytosis of fluorophore-labeled transferrin and cause a marked invagination of the plasma membrane. Many of these long plasmalemmal invaginations had clathrin-coated pits along their cytoplasmic surface. A number of distinct noncoated pits resembling plasmalemmal caveolae also accumulated in anti-dynamin antibody-injected cells. Further, the cellular uptake of cholera toxin B, which normally occurs by the internalization of caveolae, was inhibited in these cells. In support of these observations, immunoisolation techniques, double-label immuno-FM, and immunoelectron microscopy (immuno-EM) provided biochemical and morphological evidence that dynamin associates with plasmalemmal caveolae. Together, these observations indicate that dynamin mediates scission from the plasma membrane of both clathrin-coated pits and caveolae during distinct endocytic processes. These results demonstrate that dynamin isoforms are involved in an additional endocytic process that is distinct from clathrin-mediated endocytosis and provide significant insights into the molecular mechanisms governing the GTP-mediated internalization of caveolae. Evidence is provided demonstrating that dynamin isoforms have a differential distribution in mammalian cells. Targeting information for these isoforms is provided at least in part by regions of alternative splicing. Thus, the different dynamin isoforms may be localized to distinct cellular compartments but provide a similar scission function during the biogenesis of nascent cytoplasmic vesicles.
Topics: Animals; Cytoplasm; Dynamins; Endocytosis; GTP Phosphohydrolases; Protein Isoforms
PubMed: 10619136
DOI: 10.1096/fasebj.13.9002.s243 -
PloS One 2021Current chemotherapy for treatment of pediatric acute leukemia, although generally successful, is still a matter of concern due to treatment resistance, relapses and...
Current chemotherapy for treatment of pediatric acute leukemia, although generally successful, is still a matter of concern due to treatment resistance, relapses and life-long side effects for a subset of patients. Inhibition of dynamin, a GTPase involved in clathrin-mediated endocytosis and regulation of the cell cycle, has been proposed as a potential anti-cancer regimen, but the effects of dynamin inhibition on leukemia cells has not been extensively addressed. Here we adopted single cell and whole-population analysis by flow cytometry and live imaging, to assess the effect of dynamin inhibition (Dynasore, Dyngo-4a, MitMAB) on pediatric acute leukemia cell lines (CCRF-CEM and THP-1), human bone marrow biopsies from patients diagnosed with acute lymphoblastic leukemia (ALL), as well as in a model of lymphoma (EL4)-induced tumor growth in mice. All inhibitors suppressed proliferation and induced pronounced caspase-dependent apoptotic cell death in CCRF-CEM and THP-1 cell lines. However, the inhibitors showed no effect on bone marrow biopsies, and did not prevent EL4-induced tumor formation in mice. We conclude that dynamin inhibition affects highly proliferating human leukemia cells. These findings form a basis for evaluation of the potential, and constraints, of employing dynamin inhibition in treatment strategies against leukemia and other malignancies.
Topics: Animals; Apoptosis; Bone Marrow Cells; Caspases; Cell Cycle; Cell Death; Cell Line, Tumor; Child; Dynamins; Endocytosis; Flow Cytometry; Heterografts; Humans; Mice; Pediatrics; Precursor Cell Lymphoblastic Leukemia-Lymphoma
PubMed: 34492077
DOI: 10.1371/journal.pone.0256708 -
Journal of Protein Chemistry Apr 1999The GTPase activity of dynamin is obligatorily coupled, by a mechanism yet unknown, to the internalization of clathrin-coated endocytic vesicles. Dynamin oligomerizes in...
The GTPase activity of dynamin is obligatorily coupled, by a mechanism yet unknown, to the internalization of clathrin-coated endocytic vesicles. Dynamin oligomerizes in vitro and in vivo and both its mechanical and enzymatic activities appear to be mediated by this self-assembly. In this study we demonstrate that dynamin is characterized by a tetramer/monomer equilibrium with an equilibrium constant of 1.67 x 10(17) M(-3). Stopped-flow fluorescence experiments show that the association rate constant for 2'(3')-O-N-methylanthraniloyl (mant)GTP is 7.0 x 10(-5) M(-1) s(-1) and the dissociation rate constant is 2.1 s(-1), whereas the dissociation rate constant for mantdeoxyGDP is 93 s(-1). We also demonstrate the cooperativity of dynamin binding and GTPase activation on a microtubule lattice. Our results indicate that dynamin self-association is not a sufficient condition for the expression of maximal GTPase activity, which suggests that dynamin molecules must be in the proper conformation or orientation if they are to form an active oligomer.
Topics: Animals; Brain; Cattle; Dose-Response Relationship, Drug; Dynamins; GTP Phosphohydrolases; Kinetics; Microtubules; Models, Biological; Sodium Chloride; Time Factors; Tubulin; Ultracentrifugation
PubMed: 10395446
DOI: 10.1023/a:1021083211267 -
Bioscience Reports Nov 2022Dynamin is one of the major proteins involved in endocytosis. First identified 50 years ago in a genetic screen in Drosophila melanogaster, it has become a central... (Review)
Review
Dynamin is one of the major proteins involved in endocytosis. First identified 50 years ago in a genetic screen in Drosophila melanogaster, it has become a central player in many forms of endocytosis, such as clathrin-mediated endocytosis or synaptic vesicle endocytosis, as well as other important cellular processes such as actin remodelling. Decades of work using biochemical and structural studies, cell-free assays, live cell imaging, acute inhibition and genetic studies have led to important insights on its mode of action. Dynamin is a remarkable mechano-GTPase, which can do a lot to membranes on its own but which is, in cells, at the centre of a vast protein and lipid network and cannot work in isolation. This review summarizes the main features of dynamin structure and function and its central role in membrane remodelling events, and give an update on the latest results.
Topics: Animals; Clathrin; Drosophila melanogaster; Dynamins; Endocytosis; Transport Vesicles
PubMed: 36156116
DOI: 10.1042/BSR20211227 -
Progress in Molecular Biology and... 2013Proteins of the dynamin superfamily are mechanochemical GTPases, which mediate nucleotide-dependent membrane remodeling events. The founding member dynamin is recruited... (Review)
Review
Proteins of the dynamin superfamily are mechanochemical GTPases, which mediate nucleotide-dependent membrane remodeling events. The founding member dynamin is recruited to the neck of clathrin-coated endocytic vesicles where it oligomerizes into helical filaments. Nucleotide-hydrolysis-induced conformational changes in the oligomer catalyze scission of the vesicle neck. Here, we review recent insights into structure, function, and oligomerization of dynamin superfamily proteins and their roles in human diseases. We describe in detail the molecular mechanisms how dynamin oligomerizes at membranes and introduce a model how oligomerization is linked to membrane fission. Finally, we discuss molecular mechanisms how mutations in dynamin could lead to the congenital diseases, Centronuclear Myopathy and Charcot-Marie Tooth disease.
Topics: Animals; Disease; Dynamins; Health; Humans; Models, Molecular; Mutation; Protein Multimerization
PubMed: 23663977
DOI: 10.1016/B978-0-12-386931-9.00015-5