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Traffic (Copenhagen, Denmark) Dec 2013The GTPase dynamin has captivated researchers for over two decades, even managing to establish its own research field. Dynamin's allure is partly due to its unusual... (Review)
Review
The GTPase dynamin has captivated researchers for over two decades, even managing to establish its own research field. Dynamin's allure is partly due to its unusual biochemical properties as well as its essential role in multiple cellular processes, which include the regulation of clathrin-mediated endocytosis and of actin cytoskeleton. On the basis of the classic model, dynamin oligomerization into higher order oligomers such as rings and helices directly executes the final fission reaction in endocytosis, which results in the generation of clathrin-coated vesicles. Dynamin's role in the regulation of actin cytoskeleton is mostly explained by its interactions with a number of actin-binding and -regulating proteins; however, the molecular mechanism of dynamin's action continues to elude us. Recent insights into the mechanism and role of dynamin oligomerization in the regulation of actin polymerization point to a novel role for dynamin oligomerization in the cell.
Topics: Actin Cytoskeleton; Animals; Coated Pits, Cell-Membrane; Dynamins; Endocytosis; Humans; Microtubules; Protein Multimerization
PubMed: 23980695
DOI: 10.1111/tra.12116 -
Biochemical Society Transactions Oct 2009The GTPase dynamin is essential for CME (clathrin-mediated endocytosis), but its exact function and mechanism of action have been controversial. Here, we review findings... (Review)
Review
The GTPase dynamin is essential for CME (clathrin-mediated endocytosis), but its exact function and mechanism of action have been controversial. Here, we review findings that have led to the current models for dynamin function, either as a mechanochemical enzyme driving membrane fission or as a regulatory GTPase monitoring rate-limiting steps in CME. However, these models are not mutually exclusive and subsequent studies have provided evidence for both dynamin functions. Recent evidence derived from divergent in vivo and in vitro approaches suggests that dynamin plays a dual role in CME, functioning at early stages as a fidelity monitor to regulate clathrin-coated pit maturation and at later stages to directly catalyse membrane fission and clathrin-coated vesicle formation.
Topics: Animals; Clathrin; Dynamins; Endocytosis; GTP Phosphohydrolases; Intracellular Membranes; Microtubules
PubMed: 19754444
DOI: 10.1042/BST0371022 -
Methods in Molecular Biology (Clifton,... 2022Herein we describe the detailed synthesis of the dynamin inhibitors Phthaladyn-29 and Napthaladyn-10, and their chemical scaffold matched partner inactive compounds....
Herein we describe the detailed synthesis of the dynamin inhibitors Phthaladyn-29 and Napthaladyn-10, and their chemical scaffold matched partner inactive compounds. Combined with the assay data provided, this allows the interrogation of dynamin in vitro and potentially in vivo.
Topics: Dynamins; Endocytosis; Guanosine Triphosphate; Naphthalimides
PubMed: 35099804
DOI: 10.1007/978-1-0716-1916-2_18 -
Respiratory Research Sep 2023Macrophage migration inhibitory factor (MIF) and GTPase dynamin-related protein 1 (Drp1)-dependent aberrant mitochondrial fission are closely linked to the pathogenesis...
BACKGROUND
Macrophage migration inhibitory factor (MIF) and GTPase dynamin-related protein 1 (Drp1)-dependent aberrant mitochondrial fission are closely linked to the pathogenesis of asthma. However, it is unclear whether Drp1-mediated mitochondrial fission and its downstream targets mediate MIF-induced proliferation of airway smooth muscle cells (ASMCs) in vitro and airway remodeling in chronic asthma models. The present study aims to clarify these issues.
METHODS
In this study, primary cultured ASMCs and ovalbumin (OVA)-induced asthmatic rats were applied. Cell proliferation was detected by CCK-8 and EdU assays. Western blotting was used to detect extracellular signal-regulated kinase (ERK) 1/2, Drp1, autophagy-related markers and E-cadherin protein phosphorylation and expression. Inflammatory cytokines production, airway reactivity test, histological staining and immunohistochemical staining were conducted to evaluate the development of asthma. Transmission electron microscopy was used to observe the mitochondrial ultrastructure.
RESULTS
In primary cultured ASMCs, MIF increased the phosphorylation level of Drp1 at the Ser616 site through activation of the ERK1/2 signaling pathway, which further activated autophagy and reduced E-cadherin expression, ultimately leading to ASMCs proliferation. In OVA-induced asthmatic rats, MIF inhibitor 4-iodo-6-phenylpyrimidine (4-IPP) treatment, suppression of mitochondrial fission by Mdivi-1 or inhibiting autophagy with chloroquine phosphate (CQ) all attenuated the development of airway remodeling.
CONCLUSIONS
The present study provides novel insights that MIF promotes airway remodeling in asthma by activating autophagy and degradation of E-cadherin via ERK/Drp1 signaling pathway, suggesting that targeting MIF/ERK/Drp1 might have potential therapeutic value for the prevention and treatment of asthma.
Topics: Animals; Rats; Airway Remodeling; Macrophage Migration-Inhibitory Factors; Dynamins; Asthma; Autophagy; Cadherins
PubMed: 37674165
DOI: 10.1186/s12931-023-02526-y -
The EMBO Journal Feb 2016Vesicle release upon endocytosis requires membrane fission, catalyzed by the large GTPase dynamin. Dynamin contains five domains that together orchestrate its...
Vesicle release upon endocytosis requires membrane fission, catalyzed by the large GTPase dynamin. Dynamin contains five domains that together orchestrate its mechanochemical activity. Hydrogen-deuterium exchange coupled with mass spectrometry revealed global nucleotide- and membrane-binding-dependent conformational changes, as well as the existence of an allosteric relay element in the α2(S) helix of the dynamin stalk domain. As predicted from structural studies, FRET analyses detect large movements of the pleckstrin homology domain (PHD) from a 'closed' conformation docked near the stalk to an 'open' conformation able to interact with membranes. We engineered dynamin constructs locked in either the closed or open state by chemical cross-linking or deletion mutagenesis and showed that PHD movements function as a conformational switch to regulate dynamin self-assembly, membrane binding, and fission. This PHD conformational switch is impaired by a centronuclear myopathy-causing disease mutation, S619L, highlighting the physiological significance of its role in regulating dynamin function. Together, these data provide new insight into coordinated conformational changes that regulate dynamin function and couple membrane binding, oligomerization, and GTPase activity during dynamin-catalyzed membrane fission.
Topics: Cell Line; Dynamins; Fluorescence Resonance Energy Transfer; Guanosine Triphosphate; Humans; Hydrolysis; Intracellular Membranes; Magnetic Resonance Spectroscopy; Mutant Proteins; Protein Conformation; Protein Multimerization; Sequence Deletion
PubMed: 26783363
DOI: 10.15252/embj.201593477 -
Journal of Neurochemistry May 1996Synaptic vesicle recycling is a neuronal specialization of endocytosis that requires the GTPase activity of dynamin I and is triggered by membrane depolarization and...
Synaptic vesicle recycling is a neuronal specialization of endocytosis that requires the GTPase activity of dynamin I and is triggered by membrane depolarization and Ca2+ entry. To establish the relationship between dynamin I GTPase activity and Ca2+, we used purified dynamin I and analyzed its interaction with Ca2+ in vitro. We report that Ca2+ bound to dynamin I and this was abolished by deletion of dynamin's C-terminal tail. Phosphorylation of dynamin I by protein kinase C promoted formation of a dynamin I tetramer and increased Ca2+ binding to the protein. Moreover, Ca2+ inhibited dynamin I GTPase activity after stimulation by phosphorylation or by phospholipids but not after stimulation with a GST-SH3 fusion protein containing the SH3 domain of phosphoinositide 3-kinase. These results suggest that in resting nerve terminals, phosphorylation of dynamin I by protein kinase C converts it to a tetramer that functions as a Ca(2+)-sensing protein. By binding to Ca2+, dynamin I GTPase activity is specifically decreased, possibly to regulate synaptic vesicle recycling.
Topics: Animals; Base Sequence; Calcium; Dynamin I; Dynamins; GTP Phosphohydrolases; Molecular Sequence Data; Oligonucleotide Probes; Peptide Hydrolases; Phosphorylation; Protein Kinase C; Protein Structure, Tertiary; Rats; Rats, Sprague-Dawley
PubMed: 8780038
DOI: 10.1046/j.1471-4159.1996.66052074.x -
The Journal of Biological Chemistry Jul 2019Neurolastin is a dynamin family GTPase that also contains a RING domain and exhibits both GTPase and E3 ligase activities. It is specifically expressed in the brain and...
Neurolastin is a dynamin family GTPase that also contains a RING domain and exhibits both GTPase and E3 ligase activities. It is specifically expressed in the brain and is important for synaptic transmission, as neurolastin knockout animals have fewer dendritic spines and exhibit a reduction in functional synapses. Our initial study of neurolastin revealed that it is membrane-associated and partially co-localizes with endosomes. Using various biochemical and cell-culture approaches, we now show that neurolastin also localizes to mitochondria in HeLa cells, cultured neurons, and brain tissue. We found that the mitochondrial localization of neurolastin depends upon an N-terminal mitochondrial targeting sequence and that neurolastin is imported into the mitochondrial intermembrane space. Although neurolastin was only partially mitochondrially localized at steady state, it displayed increased translocation to mitochondria in response to neuronal stress and mitochondrial fragmentation. Interestingly, inactivation or deletion of neurolastin's RING domain also increased its mitochondrial localization. Using EM, we observed that neurolastin knockout animals have smaller but more numerous mitochondria in cerebellar Purkinje neurons, indicating that neurolastin regulates mitochondrial morphology. We conclude that the brain-specific dynamin GTPase neurolastin exhibits stress-responsive localization to mitochondria and is required for proper mitochondrial morphology.
Topics: Animals; Cells, Cultured; Dynamins; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Mutation; Protein Transport; Purkinje Cells
PubMed: 31177092
DOI: 10.1074/jbc.RA118.007245 -
The Journal of Biological Chemistry Aug 1993Dynamin is a GTPase thought to play a role in endocytosis based on genetic analysis of its homolog in Drosophila melanogaster shibire. Previous studies have stressed an...
Dynamin is a GTPase thought to play a role in endocytosis based on genetic analysis of its homolog in Drosophila melanogaster shibire. Previous studies have stressed an in vitro association with microtubules, though additional evidence suggests that dynamin associates with membranous organelles. In an analysis of the enzymatic and membrane binding properties of dynamin, we have found that the acidic phospholipids, phosphatidylserine, phosphatidylglycerol, and phosphatidylinositol, are able to stimulate GTP hydrolysis in a manner similar to activation previously shown with microtubules. A neutral phospholipid, phosphatidylcholine, had no effect on dynamin GTPase. Activation of dynamin was biphasic, with a decrease in activity back to basal levels with increased concentrations of either microtubules or liposomes. A comparison between GTPase stimulation induced by microtubules and that by phospholipids suggests that ionic interactions between the basic C-terminal domain of dynamin and the negatively charged microtubule or phospholipid head group are important. In support of this, GTPase stimulation by these agents in combination was not additive. A salt-extracted membrane fraction from brain tissue also activated dynamin GTPase, though to a lower extent than pure phospholipids. These results suggest that membrane components could be responsible for some aspects of the regulation of dynamin function in vivo.
Topics: Animals; Blotting, Western; Brain; Ca(2+) Mg(2+)-ATPase; Cattle; Drosophila Proteins; Dynamins; Enzyme Activation; GTP Phosphohydrolases; Hydrogen-Ion Concentration; Male; Microtubules; Phospholipids; Rats; Rats, Sprague-Dawley
PubMed: 8349610
DOI: No ID Found -
Journal of Biosciences Jun 2017Dynamin superfamily proteins comprising classical dynamins and related proteins are membrane remodelling agents involved in several biological processes such as... (Review)
Review
Dynamin superfamily proteins comprising classical dynamins and related proteins are membrane remodelling agents involved in several biological processes such as endocytosis, maintenance of organelle morphology and viral resistance. These large GTPases couple GTP hydrolysis with membrane alterations such as fission, fusion or tubulation by undergoing repeated cycles of self-assembly/disassembly. The functions of these proteins are regulated by various post-translational modifications that affect their GTPase activity, multimerization or membrane association. Recently, several reports have demonstrated variety of such modifications providing a better understanding of the mechanisms by which dynamin proteins influence cellular responses to physiological and environmental cues. In this review, we discuss major post-translational modifications along with their roles in the mechanism of dynamin functions and implications in various cellular processes.
Topics: Animals; Dynamins; Multigene Family; Phosphorylation; Protein Processing, Post-Translational
PubMed: 28569256
DOI: 10.1007/s12038-017-9680-y -
Cell Reports Aug 2015Membrane trafficking and spinogenesis contribute significantly to changes in synaptic strength during development and in various paradigms of synaptic plasticity....
Membrane trafficking and spinogenesis contribute significantly to changes in synaptic strength during development and in various paradigms of synaptic plasticity. GTPases of the dynamin family are key players regulating membrane trafficking. Here, we identify a brain-specific dynamin family GTPase, neurolastin (RNF112/Znf179), with closest homology to atlastin. We demonstrate that neurolastin has functional GTPase and RING domains, making it a unique protein identified with this multi-enzymatic domain organization. We also show that neurolastin is a peripheral membrane protein that localizes to endosomes and affects endosomal membrane dynamics via its RING domain. In addition, neurolastin knockout mice have fewer dendritic spines, and rescue of the wild-type phenotype requires both the GTPase and RING domains. Furthermore, we find fewer functional synapses and reduced paired pulse facilitation in neurolastin knockout mice. Thus, we identify neurolastin as a dynamin family GTPase that affects endosome size and spine density.
Topics: Animals; Dendrites; Dynamins; Endosomes; HeLa Cells; Humans; Mice; Mice, Knockout; Protein Structure, Tertiary; Rats; Rats, Sprague-Dawley; Synapses
PubMed: 26212327
DOI: 10.1016/j.celrep.2015.06.064