Cloning and partial characterization of Entamoeba histolytica PTPases.
Reversible protein tyrosine phosphorylation is an essential signal transduction mechanism that regulates cell growth, differentiation, mobility, metabolism, and survival. Two genes coding for protein tyrosine phophatases, designed EhPTPA and EhPTPB, were cloned from Entamoeba histolytica. EhPTPA and EhPTPB proteins showed amino acid sequence identity of 37%, both EhPTPases showed similarity with Dictyostelium discoideum and vertebrate trasmembranal PTPases. mRNA levels of EhPTPA gene are up-regulated in trophozoites recovered after 96h of liver abscess development in the hamster model. EhPTPA protein expressed as a glutathione S-transferase fusion protein (GST::EhPTPA) showed enzymatic activity with p-nitrophenylphosphate as a substrate and was inhibited by PTPase inhibitors vanadate and molybdate. GST::EhPTPA protein selectively dephosphorylates a 130kDa phosphotyrosine-containing protein in trophozoite cell lysates. EhPTPA gene codifies for a 43kDa native protein. Up-regulation of EhPTPA expression suggests that EhPTPA may play an important role in the adaptive response of trophozoites during amoebic liver abscess development.
Herrera-Rodríguez
Sara Elisa
SE
Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del I.P.N., México D.F, 07360, Mexico.
Baylón-Pacheco
Lidia
L
Talamás-Rohana
Patricia
P
Rosales-Encina
José Luis
JL
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D006224:Cricetinae; D004404:Dysentery, Amebic / Q000469:parasitology*; D004748:Entamoeba histolytica / Q000201:enzymology*; D004789:Enzyme Activation; D008099:Liver / Q000469:parasitology*; D008969:Molecular Sequence Data; D017027:Protein Tyrosine Phosphatases / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D017027:Protein Tyrosine Phosphatases