scholarly journals EhVps23: A Component of ESCRT-I That Participates in Vesicular Trafficking and Phagocytosis of Entamoeba histolytica

2021 ◽  
Vol 11 ◽  
Author(s):  
Ausencio Galindo ◽  
Rosario Javier-Reyna ◽  
Guillermina García-Rivera ◽  
Cecilia Bañuelos ◽  
Sarita Montaño ◽  
...  
Keyword(s):  
Entamoeba Histolytica ◽  
Vesicular Trafficking ◽  
Pivotal Role ◽  
Gene Encoding ◽  
Endosomal Sorting ◽  
Membrane Fission ◽  
Cytoplasmic Vesicles ◽  
Lysobisphosphatidic Acid ◽  
Molecular Relationships

The endosomal sorting complex required for transport (ESCRT) is formed by ESCRT-0, ESCRT-I, ESCRT-II, ESCRT-III complexes, and accessory proteins. It conducts vesicular trafficking in eukaryotes through the formation of vesicles and membrane fission and fusion events. The trophozoites of Entamoeba histolytica, the protozoan responsible for human amoebiasis, presents an active membrane movement in basal state that increases during phagocytosis and tissue invasion. ESCRT-III complex has a pivotal role during these events, but ESCRT-0, ESCRT-I and ESCRT-II have been poorly studied. Here, we unveiled the E. histolytica ESCRT-I complex and its implication in vesicular trafficking and phagocytosis, as well as the molecular relationships with other phagocytosis-involved molecules. We found a gene encoding for a putative EhVps23 protein with the ubiquitin-binding and Vps23 core domains. In basal state, it was in the plasma membrane, cytoplasmic vesicles and multivesicular bodies, whereas during phagocytosis it was extensively ubiquitinated and detected in phagosomes and connected vesicles. Docking analysis, immunoprecipitation assays and microscopy studies evidenced its interaction with EhUbiquitin, EhADH, EhVps32 proteins, and the lysobisphosphatidic acid phospholipid. The knocking down of the Ehvps23 gene resulted in lower rates of phagocytosis. Our results disclosed the concert of finely regulated molecules and vesicular structures participating in vesicular trafficking-related events with a pivotal role of EhVps23.

scholarly journals The role of VPS4 in ESCRT-III polymer remodeling

2019 ◽  
Vol 47 (1) ◽  
pp. 441-448 ◽  
Author(s):  
Christophe Caillat ◽  
Sourav Maity ◽  
Nolwenn Miguet ◽  
Wouter H. Roos ◽  
Winfried Weissenhorn
Keyword(s):  
Active Role ◽  
Mechanistic Models ◽  
Membrane Remodeling ◽  
Filament Formation ◽  
Enveloped Viruses ◽  
Endosomal Sorting ◽  
Membrane Fission ◽  
Dynamic Assembly ◽  
Inside Out

Abstract The endosomal sorting complex required for transport-III (ESCRT-III) and VPS4 catalyze a variety of membrane-remodeling processes in eukaryotes and archaea. Common to these processes is the dynamic recruitment of ESCRT-III proteins from the cytosol to the inner face of a membrane neck structure, their activation and filament formation inside or at the membrane neck and the subsequent or concomitant recruitment of the AAA-type ATPase VPS4. The dynamic assembly of ESCRT-III filaments and VPS4 on cellular membranes induces constriction of membrane necks with large diameters such as the cytokinetic midbody and necks with small diameters such as those of intraluminal vesicles or enveloped viruses. The two processes seem to use different sets of ESCRT-III filaments. Constriction is then thought to set the stage for membrane fission. Here, we review recent progress in understanding the structural transitions of ESCRT-III proteins required for filament formation, the functional role of VPS4 in dynamic ESCRT-III assembly and its active role in filament constriction. The recent data will be discussed in the context of different mechanistic models for inside-out membrane fission.

ESCRT-mediated sorting and intralumenal vesicle concatenation in plants

2018 ◽  
Vol 46 (3) ◽  
pp. 537-545 ◽  
Author(s):  
Marisa S. Otegui
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Endocytic Pathway ◽  
Endosomal Sorting ◽  
Evolutionary Diversification ◽  
Escrt Machinery ◽  
Membrane Fission ◽  
Associated Proteins

The degradation of plasma membrane and other membrane-associated proteins require their sorting at endosomes for delivery to the vacuole. Through the endocytic pathway, ubiquitinated membrane proteins (cargo) are delivered to endosomes where the ESCRT (endosomal sorting complex required for transport) machinery sorts them into intralumenal vesicles for degradation. Plants contain both conserved and plant-specific ESCRT subunits. In this review, I discuss the role of characterized plant ESCRT components, the evolutionary diversification of the plant ESCRT machinery, and a recent study showing that endosomal intralumenal vesicles form in clusters of concatenated vesicle buds by temporally uncoupling membrane constriction from membrane fission.

Myosin IB from Entamoeba histolytica is involved in phagocytosis of human erythrocytes

1999 ◽  
Vol 112 (8) ◽  
pp. 1191-1201 ◽  
Author(s):  
H. Voigt ◽  
J.C. Olivo ◽  
P. Sansonetti ◽  
N. Guillen
Keyword(s):  
Entamoeba Histolytica ◽  
Wild Type Strain ◽  
Protozoan Parasite ◽  
Wild Type ◽  
Gene Encoding ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cellular Processes ◽  
Human Parasite ◽  
Myosin I

Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery in humans. The disease is prevalent worldwide. Infection with E. histolytica results in invasion of the intestine by the parasite, followed by tissue damage and inflammation. During this invasive process, parasites kill and phagocytose human epithelial cells, immune cells and erythrocytes. Expression of amoebic pathogenicity requires a dynamic cytoskeleton that allows movement, tissue penetration and changes in parasite morphology. Myosin IB is a member of the myosin I family of motor proteins. Studies conducted both with Dictyostelium discoideum, a non-pathogenic amoeba, and with the yeast Saccharomyces cerevisiae indicate the involvement of myosin IB in cellular processes including movement, phagocytosis and endocytosis. Recently, we isolated the gene encoding myosin IB from E. histolytica. Thus, we decided to analyze the role of myosin IB in pathogenesis of amoeba. Using a specific anti-myosin IB antibody, this protein was localized in cell regions including the pseudopod, vesicles and underneath the plasma membrane. When E. histolytica was activated for erythrophagocytosis, myosin IB was markedly recruited to both the phagocytic cup and around internalized phagosomes. To analyze the role of myosin IB in phagocytosis, a strain overexpressing the myosin IB gene was constructed. This strain synthesizes threefold more myosin IB than the wild-type strain. Challenge of the transfected cell line with erythrocytes showed that these amoebae were deficient in erythrophagocytosis mainly in the uptake step, suggesting a role for myosin IB in the pathogenic activity of a human parasite.

scholarly journals Essential Role of hIST1 in Cytokinesis

2009 ◽  
Vol 20 (5) ◽  
pp. 1374-1387 ◽  
Author(s):  
Monica Agromayor ◽  
Jez G. Carlton ◽  
John P. Phelan ◽  
Daniel R. Matthews ◽  
Leo M. Carlin ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Multivesicular Body ◽  
Endosomal Sorting ◽  
Escrt Machinery ◽  
Membrane Fission ◽  
Immunodeficiency Virus ◽  
Positive Modulator ◽  
Essential Function ◽  
Hiv 1

The last steps of multivesicular body (MVB) formation, human immunodeficiency virus (HIV)-1 budding and cytokinesis require a functional endosomal sorting complex required for transport (ESCRT) machinery to facilitate topologically equivalent membrane fission events. Increased sodium tolerance (IST) 1, a new positive modulator of the ESCRT pathway, has been described recently, but an essential function of this highly conserved protein has not been identified. Here, we describe the previously uncharacterized KIAA0174 as the human homologue of IST1 (hIST1), and we report its conserved interaction with VPS4, CHMP1A/B, and LIP5. We also identify a microtubule interacting and transport (MIT) domain interacting motif (MIM) in hIST1 that is necessary for its interaction with VPS4, LIP5 and other MIT domain-containing proteins, namely, MITD1, AMSH, UBPY, and Spastin. Importantly, hIST1 is essential for cytokinesis in mammalian cells but not for HIV-1 budding, thus providing a novel mechanism of functional diversification of the ESCRT machinery. Last, we show that the hIST1 MIM activity is essential for cytokinesis, suggesting possible mechanisms to explain the role of hIST1 in the last step of mammalian cell division.

scholarly journals Ligand-independent role of ErbB3 in endocytic recycling

2019 ◽  
Author(s):  
Ana Rosa Saez-Ibanez ◽  
Julia M. Scheffler ◽  
Takeshi Terabayashi ◽  
Nina Daubel ◽  
Taija Makinen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Tyrosine Kinases ◽  
Vesicular Trafficking ◽  
Endocytic Trafficking ◽  
Endosomal Trafficking ◽  
Endocytic Recycling ◽  
Breast Epithelial Cells ◽  
Endosomal Sorting ◽  
Β1 Integrins

AbstractActivated receptor tyrosine kinases (RTKs) are important cargo of the endocytic trafficking, yet to what extent RTKs play a role in endocytic trafficking processes per se, remains unclear. Here we show that the ErbB3 receptor, frequently overexpressed in invasive cancers, sorts endocytosed cargo including β1 integrins and the transferrin receptor (TfR) for endocytic recycling in breast epithelial cells, in a manner that does not require ligand-induced ErbB3 signalling. Loss of ErbB3 abrogates recycling of β1 integrins, likely from a Rab4-positive compartment, and redirects it towards lysosomal degradation. Consequently, delivery of β1 integrins to the leading front of migrating sheets of epithelial cells is impaired and collective migration compromised upon loss of ErbB3. Mechanistically, ErbB3 interacts with the endosomal adaptors GGA3 and Rabaptin5 facilitating assembly of an Arf6-GGA3-Rabaptin5 endosomal sorting complex, to promote recycling of cargo such as integrins and TfR. Taken together, our results show that ErbB3 is an integral part of the endosomal trafficking machinery, provoking the notion that RTKs might play yet unrecognised roles in vesicular trafficking.

scholarly journals EhADH112 Is a Bro1 Domain-Containing Protein Involved in theEntamoeba histolyticaMultivesicular Bodies Pathway

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Cecilia Bañuelos ◽  
Guillermina García-Rivera ◽  
Israel López-Reyes ◽  
Leobardo Mendoza ◽  
Arturo González-Robles ◽  
...  
Keyword(s):  
Amino Acids ◽  
Entamoeba Histolytica ◽  
Protein Trafficking ◽  
Multivesicular Bodies ◽  
Accessory Proteins ◽  
Endosomal Sorting ◽  
Trafficking Pathway ◽  
Cytoplasmic Vesicles ◽  
Late Stages

EhADH112 is anEntamoeba histolyticaBro1 domain-containing protein, structurally related to mammalian ALIX and yeast BRO1, both involved in the Endosomal Sorting Complexes Required for Transport (ESCRT)-mediated multivesicular bodies (MVB) biogenesis. Here, we investigated an alternative role for EhADH112 in the MVB protein trafficking pathway by overexpressing 166 amino acids of its N-terminal Bro1 domain in trophozoites. Trophozoites displayed diminished phagocytosis rates and accumulated exogenous Bro1 at cytoplasmic vesicles which aggregated into aberrant complexes at late stages of phagocytosis, probably preventing EhADH112 function. Additionally, the existence of a putativeE. histolyticaESCRT-III subunit (EhVps32) presumably interacting with EhADH112, led us to perform pull-down experiments with GST-EhVps32 and [35S]-labeled EhADH112 or EhADH112 derivatives, confirming EhVps32 binding to EhADH112 through its Bro1 domain. Our overall results define EhADH112 as a novel member of ESCRT-accessory proteins transiently present at cellular surface and endosomal compartments, probably contributing to MVB formation during phagocytosis.

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