Identification of calcium-transporting ATPases of Entamoeba histolytica and cellular localization of the putative SERCA

Martínez-Higuera, Aarón; Salas‐Casas, Andrés; Calixto-Gálvez, Mercedes; Chávez‐Munguía, Bibiana; Pérez-Ishiwara, David Guillermo; Ximénez, Cecilia; Rodríguez, Mario A.

doi:10.1016/j.exppara.2013.06.004

Cited by 15 publications

(12 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here we searched for EhNPC1 and EhNPC2 in the ER. Confocal images of trophozoites in basal conditions showed that both proteins co-localized in networks and vacuoles with EhSERCA, an ER marker [33] (Fig 8Aa,b). EhNPC2 also appeared as 1.5 to 2 μm spheres in the cytoplasm (Fig 8A).…”

Section: Resultsmentioning

confidence: 99%

EhNPC1 and EhNPC2 Proteins Participate in Trafficking of Exogenous Cholesterol in Entamoeba histolytica Trophozoites: Relevance for Phagocytosis

et al. 2016

Self Cite

View full text Add to dashboard Cite

Entamoeba histolytica, the highly phagocytic protozoan causative of human amoebiasis lacks the machinery to synthesize cholesterol. Here, we investigated the presence of NPC1 and NPC2 proteins in this parasite, which are involved in cholesterol trafficking in mammals. Bioinformatics analysis revealed one Ehnpc1 and two Ehnpc2 genes. EhNPC1 appeared as a transmembrane protein and both EhNPC2 as peripheral membrane proteins. Molecular docking predicted that EhNPC1 and EhNPC2 bind cholesterol and interact with each other. Genes and proteins were identified in trophozoites. Serum pulse-chase and confocal microscopy assays unveiled that after trophozoites sensed the cholesterol source, EhNPC1 and EhNPC2 were organized around the plasma membrane in a punctuated pattern. Vesicles emerged and increased in number and size and some appeared full of cholesterol with EhNPC1 or EhNPC2 facing the extracellular space. Both proteins, but mostly EhNPC2, were found out of the cell associated with cholesterol. EhNPC1 and cholesterol formed networks from the plasma membrane to the nucleus. EhNPC2 appeared in erythrocytes that were being ingested by trophozoites, co-localizing with cholesterol of erythrocytes, whereas EhNPC1 surrounded the phagocytic cup. EhNPC1 and EhNPC2 co-localized with EhSERCA in the endoplasmic reticulum and with lysobisphosphatidic acid and EhADH (an Alix protein) in phagolysosomes. Immunoprecipitation assays confirmed the EhNPC1 and EhNPC2 association with cholesterol, EhRab7A and EhADH. Serum starved and blockage of cholesterol trafficking caused a low rate of phagocytosis and incapability of trophozoites to produce damage in the mouse colon. Ehnpc1 and Ehnpc2 knockdown provoked in trophozoites a lower intracellular cholesterol concentration and a diminished rate of phagocytosis; and Ehnpc1 silencing also produced a decrease of trophozoites movement. Trafficking of EhNPC1 and EhNPC2 during cholesterol uptake and phagocytosis as well as their association with molecules involved in endocytosis strongly suggest that these proteins play a key role in cholesterol uptake.

show abstract

Section: Resultsmentioning

confidence: 99%

EhNPC1 and EhNPC2 Proteins Participate in Trafficking of Exogenous Cholesterol in Entamoeba histolytica Trophozoites: Relevance for Phagocytosis

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…V-type H + ATPase and Ca 2 + transporting ATPase are also ion transport enzymes which adjust the concentration of H + and Ca 2 + , respectively. Both of them have a significant role in osmoregulation (Firmino et al, 2011;Martinez-Higuera et al, 2013).…”

Section: Discussionmentioning

confidence: 99%

Transcriptomic response to low salinity stress in gills of the Pacific white shrimp, Litopenaeus vannamei

Pan

Zhao

et al. 2015

Marine Genomics

View full text Add to dashboard Cite

“…Five putative Ca 2+ -ATPases, which could be important in the regulation of the cytoplasmic calcium concentration, have been recently identified in E . histolytica [ 64 ]. Ca 2+ -ATPases are very sensitive to OS and undergo functional and conformational changes when exposed to oxidants [ 65 ].…”

Section: Discussionmentioning

confidence: 99%

Proteomic Identification of Oxidized Proteins in Entamoeba histolytica by Resin-Assisted Capture: Insights into the Role of Arginase in Resistance to Oxidative Stress

et al. 2016

View full text Add to dashboard Cite

Entamoeba histolytica is an obligate protozoan parasite of humans, and amebiasis, an infectious disease which targets the intestine and/or liver, is the second most common cause of human death due to a protozoan after malaria. Although amebiasis is usually asymptomatic, E. histolytica has potent pathogenic potential. During host infection, the parasite is exposed to reactive oxygen species that are produced and released by cells of the innate immune system at the site of infection. The ability of the parasite to survive oxidative stress (OS) is essential for a successful invasion of the host. Although the effects of OS on the regulation of gene expression in E. histolytica and the characterization of some proteins whose function in the parasite's defense against OS have been previously studied, our knowledge of oxidized proteins in E. histolytica is lacking. In order to fill this knowledge gap, we performed a large-scale identification and quantification of the oxidized proteins in oxidatively stressed E. histolytica trophozoites using resin-assisted capture coupled to mass spectrometry. We detected 154 oxidized proteins (OXs) and the functions of some of these proteins were associated with antioxidant activity, maintaining the parasite's cytoskeleton, translation, catalysis, and transport. We also found that oxidation of the Gal/GalNAc impairs its function and contributes to the inhibition of E. histolytica adherence to host cells. We also provide evidence that arginase, an enzyme which converts L-arginine into L-ornithine and urea, is involved in the protection of the parasite against OS. Collectively, these results emphasize the importance of OS as a critical regulator of E. histolytica's functions and indicate a new role for arginase in E. histolytica's resistance to OS.

show abstract

Identification of calcium-transporting ATPases of Entamoeba histolytica and cellular localization of the putative SERCA

Cited by 15 publications

References 46 publications

EhNPC1 and EhNPC2 Proteins Participate in Trafficking of Exogenous Cholesterol in Entamoeba histolytica Trophozoites: Relevance for Phagocytosis

EhNPC1 and EhNPC2 Proteins Participate in Trafficking of Exogenous Cholesterol in Entamoeba histolytica Trophozoites: Relevance for Phagocytosis

Transcriptomic response to low salinity stress in gills of the Pacific white shrimp, Litopenaeus vannamei

Proteomic Identification of Oxidized Proteins in Entamoeba histolytica by Resin-Assisted Capture: Insights into the Role of Arginase in Resistance to Oxidative Stress

Contact Info

Product

Resources

About