title: Entamoeba invadens: Identification of a SERCA protein and effect of SERCA inhibitors on encystation.
abstract: Calcium has an important role on signaling of different cellular processes, including growth and differentiation. Signaling by calcium also has an essential function in pathogenesis and differentiation of the protozoan parasites Entamoeba histolytica and Entamoeba invadens. However, the proteins of these parasites that regulate the cytoplasmic concentration of this ion are poorly studied. In eukaryotic cells, the calcium-ATPase of the SERCA type plays an important role in calcium homeostasis by catalyzing the active efflux of calcium from cytoplasm to endoplasmic reticulum. Here, we reported the identification of SERCA of E. invadens (EiSERCA). This protein contains a putative sequence for endoplasmic reticulum retention and all domains involved in calcium transport identified in mammalian SERCA. By immunofluorescence assays, an antibody against SERCA of E. histolytica detected EiSERCA in a vesicular network in the cytoplasm of E. invadens trophozoites, co-localizing with calreticulin. Interestingly, EiSERCA was redistributed close to plasma membrane during encystation, suggesting that this pump could participate in regulate the calcium concentration during this process. In addition, thapsigargin and cyclopiazonic acid, both specific inhibitors of SERCA, affected the number and structure of cysts, supporting the hypothesis that calcium flux mediated by SERCA has an important role in the life cycle of Entamoeba.
authors: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, México, D.F. 07000, Mexico.
authors: Aarón
authors: A
authors: Martínez-Higuera
authors: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, México, D.F. 07000, Mexico.
authors: Mayra
authors: M
authors: Herrera-Martínez
authors: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, México, D.F. 07000, Mexico.
authors: Bibiana
authors: B
authors: Chávez-Munguía
authors: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, México, D.F. 07000, Mexico.
authors: Martha
authors: M
authors: Valle-Solís
authors: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, México, D.F. 07000, Mexico.
authors: Marcos A
authors: MA
authors: Muñiz-Lino
authors: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, México, D.F. 07000, Mexico.
authors: Javier
authors: J
authors: Cázares-Apátiga
authors: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, México, D.F. 07000, Mexico. Electronic address: marodri@cinvestav.mx.
authors: Mario A
authors: MA
authors: Rodríguez
mesh_terms: D000252:Calcium-Transporting ATPases / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000235:genetics; D037282:Calreticulin / Q000032:analysis; D004747:Entamoeba / Q000187:drug effects* / Q000254:growth & development*; D004791:Enzyme Inhibitors / Q000378:metabolism; D007211:Indoles / Q000378:metabolism; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D015800:Protozoan Proteins / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000235:genetics; D033761:Spores, Protozoan / Q000187:drug effects* / Q000254:growth & development*; D019284:Thapsigargin / Q000378:metabolism; D022161:Transport Vesicles / Q000737:chemistry
chemical_list: D037282:Calreticulin; D004791:Enzyme Inhibitors; D007211:Indoles; D015800:Protozoan Proteins; D019284:Thapsigargin; D000252:Calcium-Transporting ATPases; C000543:cyclopiazonic acid
keywords: Calcium homeostasis; Cyclopiazonic acid; Encystation; Entamoeba invadens; SERCA; Thapsigargin