Molecular Genetics of the Secretory Pathway in Entamoeba histolytica

2000 ◽  
Vol 31 (4) ◽  
pp. S151-S152 ◽  
Author(s):  
Rosana Sánchez-López ◽  
Angeles Gutiérrez ◽  
Patricia Juárez ◽  
Alejandro Olvera ◽  
Felipe Olvera ◽  
...  
2018 ◽  
Vol 117 (11) ◽  
pp. 3381-3389 ◽  
Author(s):  
Mario A. Rodríguez ◽  
Aarón Martínez-Higuera ◽  
Martha I. Valle-Solis ◽  
Mario Hernandes-Alejandro ◽  
Bibiana Chávez-Munguía ◽  
...  

1999 ◽  
Vol 2 (3) ◽  
pp. 188-197 ◽  
Author(s):  
Esther Orozco ◽  
Consuelo Gómez ◽  
D.Guillermo Pérez

2000 ◽  
Vol 31 (4) ◽  
pp. S157-S159 ◽  
Author(s):  
Patricia Juárez ◽  
Rosana Sánchez-López ◽  
Marco A Ramos ◽  
Roberto P Stock ◽  
Alejandro Alagón

2001 ◽  
Vol 116 (2) ◽  
pp. 223-228 ◽  
Author(s):  
Patricia Juárez ◽  
Rosana Sanchez-Lopez ◽  
Roberto P. Stock ◽  
Alejandro Olvera ◽  
Marco A. Ramos ◽  
...  

2005 ◽  
Vol 109 (4) ◽  
pp. 241-251 ◽  
Author(s):  
Ricardo Sánchez ◽  
Andrés Saralegui ◽  
Alfonso Olivos-García ◽  
Carlo Scapolla ◽  
Gianluca Damonte ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mrinalini Roy ◽  
Sanket Kaushik ◽  
Anupam Jyoti ◽  
Vijay Kumar Srivastava

Entamoeba histolytica (Eh) is a pathogenic eukaryote that often resides silently in humans under asymptomatic stages. Upon indeterminate stimulus, it develops into fulminant amoebiasis that causes severe hepatic abscesses with 50% mortality. This neglected tropical pathogen relies massively on membrane modulation to flourish and cause disease; these modulations range from the phagocytic mode for food acquisition to a complex trogocytosis mechanism for tissue invasion. Rab GTPases form the largest branch of the Ras-like small GTPases, with a diverse set of roles across the eukaryotic kingdom. Rab GTPases are vital for the orchestration of membrane transport and the secretory pathway responsible for transporting the pathogenic effectors, such as cysteine proteases (EhCPs) which help in tissue invasion. Rab GTPases thus play a crucial role in executing the cytolytic effect of E. histolytica. First, they interact with Gal/Nac lectins required for adhering to the host cells, and then, they assist in the secretion of EhCPs. Additionally, amoebic Rab GTPases are vital for encystation because substantial vesicular trafficking is required to create dormant amoebic cysts. These cysts are the infective agent and help to spread the disease. The absence of a “bonafide” vesicular transport machinery in Eh and the existence of a diverse repertoire of amoebic Rab GTPases (EhRab) hint at their contribution in supporting this atypical machinery. Here, we provide insights into a pseudoRab GTPase, EhRabX10, by performing physicochemical analysis, predictive 3D structure modeling, protein-protein interaction studies, and in silico molecular docking. Our group is the first one to classify EhRabX10 as a pseudoRab GTPase with four nonconserved G-motifs. It possesses the basic fold of the P-loop containing nucleotide hydrolases. Through this in silico study, we provide an introduction to the characterization of the atypical EhRabX10 and set the stage for future explorations into the mechanisms of nucleotide recognition, binding, and hydrolysis employed by the pseudoEhRab GTPase family.


2000 ◽  
Vol 31 (4) ◽  
pp. S153-S154 ◽  
Author(s):  
Rebeca Manning-Cela ◽  
Eloisa M Carbajal ◽  
Isaura Meza

1999 ◽  
Vol 67 (6) ◽  
pp. 3073-3081 ◽  
Author(s):  
Sudip K. Ghosh ◽  
Jessica Field ◽  
Marta Frisardi ◽  
Benjamin Rosenthal ◽  
Zhiming Mai ◽  
...  

ABSTRACT Entamoeba histolytica, the protozoan parasite that phagocytoses bacteria and host cells, has a vesicle/vacuole-filled cytosol like that of macrophages. In contrast, the infectious cyst form has four nuclei and a chitin wall. Here, anti-chitinase antibodies identified hundreds of small secretory vesicles in encysting E. invadens parasites and in E. histolytica trophozoites overexpressing chitinase under an actin gene promoter. Abundant small secretory vesicles were also identified with antibodies to the surface antigen Ariel and with a fluorescent substrate of cysteine proteinases. Removal of an N-terminal signal sequence directed chitinase to the cytosol. Addition of a C-terminal KDEL peptide, identified on amebic BiP, retained chitinase in a putative endoplasmic reticulum, which was composed of a few vesicles of mixed sizes. A putative Golgi apparatus, which was Brefeldin A sensitive and composed of a few large, perinuclear vesicles, was identified with antibodies to ADP-ribosylating factor and to ɛ-COP. We conclude that the amebic secretory pathway is similar to those of other eukaryotic cells, even if its appearance is somewhat different.


Author(s):  
W. Bernard

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.


Author(s):  
Norberto Treviño ◽  
Alfredo Feria-Velasco ◽  
I. Ruiz de Chávez

Although erythrophagocytosis by various species of Entamoeba is a well known phenomenon this has not yet been studied in detail at the ultrastructural level. The present work deals with the description of the incorporation process of erythrocytes by trophozoites of E. histolytica. For this study, trophozoites of E. histolytica, HK-9:NIH strain cultured in axenic conditions and washed human erythrocytes were placed on a hot plate at 37°C in physiological saline solution. After 5 minutes, 2.5% glutarldehyde was added and the samples were processed according to conventional techniques for electron microscopy.Based upon light microscopy studies on living trophozoites in contact with erythrocytes, it seems that erythrophagocytosis only takes place in one pole of the parasite.


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