Search results for "Clathrin"
showing 8 items of 48 documents
Agonist and antagonist-dependent internalization of the human vasopressin V2 receptor.
1998
Abstract In this report we demonstrate that in HEK293 cells stably expressing the human V2vasopressin receptor, ligand-induced internalization of the hormone receptor occurs via the clathrin-dependent pathway. Studies of receptor trafficking either by direct visualization of the V2receptor by confocal microscopy or binding experiments show a rapid internalization (half-time 6–7 min). Blocking of the clathrin-dependent pathway by hypertonic sucrose increased vasopressin-induced cellular cAMP production and decreased the desensitization of the V2receptor–adenylyl cyclase system. Thus, internalization appears to be a major regulatory mechanism terminating vasopressin action in HEK293 cells. Tw…
Cryptogein treatment stimulates clathrin-endocytosis correlated with ROS production in tobacco cells
2007
International audience; During plant pathogen interactions, specific molecules elicit defense response of plant cells. Cryptogein, an elicitin produced by the pathogenic fungus Phytophtora cryptogea, induces a hypersensitive response (HR) in tobacco plants. The mode of action for cryptogein starts with recognition of this elicitor by an unidentified plasma membrane (PM) receptor. This ligand-receptor binding trigger a cascade of events at the PM level including rapid calcium influx, ions effluxes, extracellular medium alcalinization and plasma membrane depolarization both in tobacco plants and suspension cells. These events lead to the activation of plasma membrane-bound NADPH oxidase, Ntrb…
Membrane transport in the endocytic pathway: Animal versus plant cells
2000
The endocytic pathway is a well established process in animal cells, but it is not well understood in plant cells. At the morphological level, all the compartments involved in endocytosis in animal cells seem to have counterparts in plant cells, and the organization of the pathway appears to share some striking similarities. Several Rab homologues have been found in plant cells, including homologues of Rab5, Rab7, and Rab11, markers of endocytic compartments in animal cells. Coat proteins are also present in plant cells, including clathrin, adaptins, and ADP ribosylation factor proteins. However, endocytic compartments in plant cells also exhibit specific features both in organization and f…
Serological Levels of Anti-clathrin Antibodies Are Decreased in Patients With Pseudoexfoliation Glaucoma
2021
Evidence for immunologic contribution to glaucoma pathophysiology is steadily increasing in ophthalmic research. Particularly, an altered abundance of circulating autoantibodies to ocular antigens is frequently observed. Here, we report an analysis of autoantibody abundancies to selected antigens in sera of open-angle glaucoma patients, subdivided into normal-tension glaucoma (N = 31), primary open-angle glaucoma (N = 43) and pseudoexfoliation glaucoma (N = 45), vs. a non-glaucomatous control group (N = 46). Serum samples were analyzed by protein microarray, including 38 antigens. Differences in antibody levels were assessed by ANOVA. Five serological antibodies showed significantly altered…
Putative sorting signals involved in PIN1 trafficking
2013
Las auxinas son hormonas vegetales involucradas en muchos procesos fisiológicos, tales como el crecimiento y diferenciación celular, la maduración de los frutos, la floración o los tropismos. Su transporte a través de la planta es polar, jugando un papel esencial en la regulación del crecimiento y el desarrollo y contribuyendo al mantenimiento de la polaridad global de la planta. La polaridad en el flujo de auxinas es debida, al menos en parte, a la distribución polar de los transportadores de salida de auxina de la familia PIN. En Arabidopsis thaliana se han identificado 8 transportadores PIN diferentes. Todos ellos presentan una estructura similar, con un dominio citosólico central que se…
Etude de l’implication de l'endocytose à clathrine dans les réactions de défense déclenchées par la cryptogéine chez le tabac
2012
La cryptogéine est un éliciteur protéique des réactions de défense chez le tabac sécrété par l’oomycète Phytophthora cryptogea. Son interaction avec un récepteur encore non identifié de la membrane plasmique déclenche une cascade d’événements de signalisation qui conduisent à une reprogrammation génique, à la diffusion d’un signal conférant une résistance systémique et, ultimement, à la mort des cellules directement exposées à cet éliciteur. Notre équipe avait précédemment mis en évidence une stimulation de la formation de vésicules d’endocytose quelques minutes après l’élicitation. Des études de microscopie électronique et d’inhibition pharmacologique avait permis d’émettre l’hypothèse que…
Human Papillomavirus Types 16, 18, and 31 Share Similar Endocytic Requirements for Entry
2013
ABSTRACT Human papillomavirus type 18 (HPV18), one of the HPVs with malignant potential, enters cells by an unknown endocytic mechanism. The key cellular requirements for HPV18 endocytosis were tested in comparison to those for HPV16 and -31 endocytoses. HPV18 (like HPV16 and -31) entry was independent of clathrin, caveolin, dynamin, and lipid rafts but required actin polymerization and tetraspanin CD151, and the viruses were routed to the same LAMP-1-positive compartment. Hence, the viruses shared similar cellular requirements for endocytic entry.
Clathrin- and Caveolin-Independent Entry of Human Papillomavirus Type 16—Involvement of Tetraspanin-Enriched Microdomains (TEMs)
2008
BACKGROUND: Infectious entry of human papillomaviruses into their host cells is an important step in the viral life cycle. For cell binding these viruses use proteoglycans as initial attachment sites. Subsequent transfer to a secondary receptor molecule seems to be involved in virus uptake. Depending on the papillomavirus subtype, it has been reported that entry occurs by clathrin- or caveolin-mediated mechanisms. Regarding human papillomavirus type 16 (HPV16), the primary etiologic agent for development of cervical cancer, clathrin-mediated endocytosis was described as infectious entry pathway. METHODOLOGY/PRINCIPAL FINDINGS: Using immunofluorescence and infection studies we show in contra…