scholarly journals Rab11 Is Required for Membrane Trafficking and Actomyosin Ring Constriction in Meiotic Cytokinesis of Drosophila Males

2007 ◽  
Vol 18 (12) ◽  
pp. 5034-5047 ◽  
Author(s):  
Maria Grazia Giansanti ◽  
Giorgio Belloni ◽  
Maurizio Gatti
Keyword(s):  
Membrane Trafficking ◽  
Membrane Vesicle ◽  
Small Gtpase ◽  
Cleavage Furrow ◽  
Wheel Drive ◽  
Abnormal Accumulation ◽  
Ring Constriction ◽  
Phosphatidylinositol Transfer ◽  
Phosphatidylinositol 4 ◽  
Four Wheel Drive

Rab11 is a small GTPase that regulates several aspects of vesicular trafficking. Here, we show that Rab11 accumulates at the cleavage furrow of Drosophila spermatocytes and that it is essential for cytokinesis. Mutant spermatocytes form regular actomyosin rings, but these rings fail to constrict to completion, leading to cytokinesis failures. rab11 spermatocytes also exhibit an abnormal accumulation of Golgi-derived vesicles at the telophase equator, suggesting a defect in membrane–vesicle fusion. These cytokinesis phenotypes are identical to those elicited by mutations in giotto (gio) and four wheel drive (fwd) that encode a phosphatidylinositol transfer protein and a phosphatidylinositol 4-kinase, respectively. Double mutant analysis and immunostaining for Gio and Rab11 indicated that gio, fwd, and rab11 function in the same cytokinetic pathway, with Gio and Fwd acting upstream of Rab11. We propose that Gio and Fwd mediate Rab11 recruitment at the cleavage furrow and that Rab11 facilitates targeted membrane delivery to the advancing furrow.

scholarly journals Rab1 interacts with GOLPH3 and controls Golgi structure and contractile ring constriction during cytokinesis in Drosophila melanogaster

Open Biology ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 160257 ◽  
Author(s):  
Stefano Sechi ◽  
Anna Frappaolo ◽  
Roberta Fraschini ◽  
Luisa Capalbo ◽  
Marco Gottardo ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Membrane Trafficking ◽  
Molecular Mechanisms ◽  
Super Resolution ◽  
Cleavage Furrow ◽  
Contractile Ring ◽  
Cog Complex ◽  
Dividing Cells ◽  
Ring Constriction ◽  
Phosphatidylinositol 4

Cytokinesis requires a tight coordination between actomyosin ring constriction and new membrane addition along the ingressing cleavage furrow. However, the molecular mechanisms underlying vesicle trafficking to the equatorial site and how this process is coupled with the dynamics of the contractile apparatus are poorly defined. Here we provide evidence for the requirement of Rab1 during cleavage furrow ingression in cytokinesis. We demonstrate that the gene omelette ( omt ) encodes the Drosophila orthologue of human Rab1 and is required for successful cytokinesis in both mitotic and meiotic dividing cells of Drosophila melanogaster . We show that Rab1 protein colocalizes with the conserved oligomeric Golgi (COG) complex Cog7 subunit and the phosphatidylinositol 4-phosphate effector GOLPH3 at the Golgi stacks. Analysis by transmission electron microscopy and 3D-SIM super-resolution microscopy reveals loss of normal Golgi architecture in omt mutant spermatocytes indicating a role for Rab1 in Golgi formation. In dividing cells, Rab1 enables stabilization and contraction of actomyosin rings. We further demonstrate that GTP-bound Rab1 directly interacts with GOLPH3 and controls its localization at the Golgi and at the cleavage site . We propose that Rab1, by associating with GOLPH3, controls membrane trafficking and contractile ring constriction during cytokinesis.

The roles of the oncoprotein GOLPH3 in contractile ring assembly and membrane trafficking during cytokinesis

2015 ◽  
Vol 43 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Stefano Sechi ◽  
Anna Frappaolo ◽  
Giorgio Belloni ◽  
Maria Grazia Giansanti
Keyword(s):  
Membrane Trafficking ◽  
Cancer Biology ◽  
Molecular Mechanisms ◽  
Cleavage Furrow ◽  
The Novel ◽  
Ring Assembly ◽  
Dividing Cells ◽  
Ring Constriction ◽  
Phosphatidylinositol 4 ◽  
Cytoskeleton Dynamics

Cytokinesis is an intricate process that requires an intimate interplay between actomyosin ring constriction and plasma membrane remodelling at the cleavage furrow. However, the molecular mechanisms involved in coupling the cytoskeleton dynamics with vesicle trafficking during cytokinesis are poorly understood. The highly conserved Golgi phosphoprotein 3 (GOLPH3), functions as a phosphatidylinositol 4-phosphate (PI4P) effector at the Golgi. Recent studies have suggested that GOLPH3 is up-regulated in several cancers and is associated with poor prognosis and more aggressive tumours. In Drosophila melanogaster, GOLPH3 localizes at the cleavage furrow of dividing cells, is required for successful cytokinesis and acts as a key molecule in coupling phosphoinositide (PI) signalling with actomyosin ring dynamics. Because cytokinesis failures have been linked with pre-malignant disease and cancer, the novel connection between GOLPH3 and cytokinesis imposes new fields of investigation in cancer biology and therapy.

A phospholipid kinase regulates actin organization and intercellular bridge formation during germline cytokinesis

Development ◽  
2000 ◽  
Vol 127 (17) ◽  
pp. 3855-3864 ◽  
Author(s):  
J.A. Brill ◽  
G.R. Hime ◽  
M. Scharer-Schuksz ◽  
M.T. Fuller
Keyword(s):  
Critical Role ◽  
Male Meiosis ◽  
Intercellular Bridge ◽  
Bridge Formation ◽  
Actin Organization ◽  
Developmental Context ◽  
Daughter Cells ◽  
Wheel Drive ◽  
Phosphatidylinositol 4 ◽  
Four Wheel Drive

The endgame of cytokinesis can follow one of two pathways depending on developmental context: resolution into separate cells or formation of a stable intercellular bridge. Here we show that the four wheel drive (fwd) gene of Drosophila melanogaster is required for intercellular bridge formation during cytokinesis in male meiosis. In fwd mutant males, contractile rings form and constrict in dividing spermatocytes, but cleavage furrows are unstable and daughter cells fuse together, producing multinucleate spermatids. fwd is shown to encode a phosphatidylinositol 4-kinase (PI 4-kinase), a member of a family of proteins that perform the first step in the synthesis of the key regulatory membrane phospholipid PIP2. Wild-type activity of the fwd PI 4-kinase is required for tyrosine phosphorylation in the cleavage furrow and for normal organization of actin filaments in the constricting contractile ring. Our results suggest a critical role for PI 4-kinases and phosphatidylinositol derivatives during the final stages of cytokinesis.

scholarly journals Nir2, a Human Homolog of Drosophila melanogaster Retinal Degeneration B Protein, Is Essential for Cytokinesis

2002 ◽  
Vol 22 (14) ◽  
pp. 5064-5075 ◽  
Author(s):  
Vladimir Litvak ◽  
Donguha Tian ◽  
Shari Carmon ◽  
Sima Lev
Keyword(s):  
Time Lapse ◽  
Eukaryotic Cell ◽  
Small Gtpase ◽  
Cleavage Furrow ◽  
Cleavage Sites ◽  
Cellular Functions ◽  
Daughter Cells ◽  
Interphase Cells ◽  
Phosphatidylinositol Transfer ◽  
Cytoskeletal Networks

ABSTRACT Cytokinesis, the final stage of eukaryotic cell division, ensures the production of two daughter cells. It requires fine coordination between the plasma membrane and cytoskeletal networks, and it is known to be regulated by several intracellular proteins, including the small GTPase Rho and its effectors. In this study we provide evidence that the protein Nir2 is essential for cytokinesis. Microinjection of anti-Nir2 antibodies into interphase cells blocks cytokinesis, as it results in the production of multinucleate cells. Immunolocalization studies revealed that Nir2 is mainly localized in the Golgi apparatus in interphase cells, but it is recruited to the cleavage furrow and the midbody during cytokinesis. Nir2 colocalizes with the small GTPase RhoA in the cleavage furrow and the midbody, and it associates with RhoA in mitotic cells. Its N-terminal region, which contains a phosphatidylinositol transfer domain and a novel Rho-inhibitory domain (Rid), is required for normal cytokinesis, as overexpression of an N-terminal-truncated mutant blocks cytokinesis completion. Time-lapse videomicroscopy revealed that this mutant normally initiates cytokinesis but fails to complete it, due to cleavage furrow regression, while Rid markedly affects cytokinesis due to abnormal contractility. Rid-expressing cells exhibit aberrant ingression and ectopic cleavage sites; the cells fail to segregate into daughter cells and they form a long unseparated bridge-like cytoplasmic structure. These results provide new insight into the cellular functions of Nir2 and introduce it as a novel regulator of cytokinesis.

scholarly journals Loss of the GARP but not EARP protein complex drives Golgi sterol overload during dendrite remodeling

2021 ◽  
Author(s):  
Caitlin E. O'Brien ◽  
Susan H. Younger ◽  
Lily Yeh Jan ◽  
Yuh Nung Jan
Keyword(s):  
Membrane Trafficking ◽  
Vesicle Trafficking ◽  
Specific Protein ◽  
Neuronal Morphology ◽  
Lipid Transfer ◽  
Oxysterol Binding Protein ◽  
Wheel Drive ◽  
Dendrite Morphogenesis ◽  
Golgi Network ◽  
Four Wheel Drive

Membrane trafficking is essential for sculpting neuronal morphology. The GARP and EARP complexes are conserved tethers that regulate vesicle trafficking in the secretory and endolysosomal pathways, respectively. Both complexes contain the Vps51, Vps52, and Vps53 proteins, and a complex-specific protein: Vps54 in GARP and Vps50 in EARP. In Drosophila, we find that both complexes are required for dendrite morphogenesis during developmental remodeling of multidendritic class IV da (c4da) neurons. Having found that sterol accumulates at the trans-Golgi network (TGN) in Vps54KO/KO neurons, we investigated genes that regulate sterols and related lipids at the TGN. Overexpression of oxysterol binding protein (Osbp) or knockdown of the PI4K four wheel drive (fwd) exacerbates the Vps54KO/KO phenotype, whereas eliminating one allele of Osbp rescues it, suggesting that excess sterol accumulation at the TGN is, in part, responsible for inhibiting dendrite regrowth. These findings distinguish the GARP and EARP complexes in neurodevelopment and implicate vesicle trafficking and lipid transfer pathways in dendrite morphogenesis.

scholarly journals Distinct roles of Rho1, Cdc42, and Cyk3 in septum formation and abscission during yeast cytokinesis

2013 ◽  
Vol 202 (2) ◽  
pp. 311-329 ◽  
Author(s):  
Masayuki Onishi ◽  
Nolan Ko ◽  
Ryuichi Nishihama ◽  
John R. Pringle
Keyword(s):  
Small Gtpase ◽  
Dominant Negative ◽  
Cleavage Furrow ◽  
Genetic Screens ◽  
General Role ◽  
Guanosine Diphosphate ◽  
Septum Formation ◽  
Primary Septum ◽  
Ring Constriction ◽  
Guanosine Triphosphatase

In yeast and animal cytokinesis, the small guanosine triphosphatase (GTPase) Rho1/RhoA has an established role in formation of the contractile actomyosin ring, but its role, if any, during cleavage-furrow ingression and abscission is poorly understood. Through genetic screens in yeast, we found that either activation of Rho1 or inactivation of another small GTPase, Cdc42, promoted secondary septum (SS) formation, which appeared to be responsible for abscission. Consistent with this hypothesis, a dominant-negative Rho1 inhibited SS formation but not cleavage-furrow ingression or the concomitant actomyosin ring constriction. Moreover, Rho1 is temporarily inactivated during cleavage-furrow ingression; this inactivation requires the protein Cyk3, which binds Rho1-guanosine diphosphate via its catalytically inactive transglutaminase-like domain. Thus, unlike the active transglutaminases that activate RhoA, the multidomain protein Cyk3 appears to inhibit activation of Rho1 (and thus SS formation), while simultaneously promoting cleavage-furrow ingression through primary septum formation. This work suggests a general role for the catalytically inactive transglutaminases of fungi and animals, some of which have previously been implicated in cytokinesis.

scholarly journals Novel and Converging Ways of NOX2 and SOD3 in Trafficking and Redox Signaling in Macrophages

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 172
Author(s):  
Steen Vang Petersen ◽  
Nanna Bach Poulsen ◽  
Cecilie Linneberg Matthiesen ◽  
Frederik Vilhardt
Keyword(s):  
Hydrogen Peroxide ◽  
Membrane Trafficking ◽  
Spatial Organization ◽  
Redox Signaling ◽  
Small Gtpase ◽  
Paracrine Signaling ◽  
Tissue Macrophage ◽  
Storage Vesicles ◽  
Superoxide Dismutase 3 ◽  
Macrophage Populations

Macrophages and related tissue macrophage populations use the classical NADPH oxidase (NOX2) for the regulated production of superoxide and derived oxidants for pathogen combat and redox signaling. With an emphasis on macrophages, we discuss how sorting into secretory storage vesicles, agonist-responsive membrane trafficking, and segregation into sphingolipid and cholesterol-enriched microdomains (lipid rafts) determine the subcellular distribution and spatial organization of NOX2 and superoxide dismutase-3 (SOD3). We discuss how inflammatory activation of macrophages, in part through small GTPase Rab27A/B regulation of the secretory compartments, mediates the coalescence of these two proteins on the cell surface to deliver a focalized hydrogen peroxide output. In interplay with membrane-embedded oxidant transporters and redox sensitive target proteins, this arrangement allows for the autocrine and paracrine signaling, which govern macrophage activation states and transcriptional programs. By discussing examples of autocrine and paracrine redox signaling, we highlight why formation of spatiotemporal microenvironments where produced superoxide is rapidly converted to hydrogen peroxide and conveyed immediately to reach redox targets in proximal vicinity is required for efficient redox signaling. Finally, we discuss the recent discovery of macrophage-derived exosomes as vehicles of NOX2 holoenzyme export to other cells.

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