Entamoeba histolytica: Molecular cloning and characterization of a novel neutral sphingomyelinase

详细信息    查看全文

• 作者：Claudia Leticia Mendoza-Mací ; as ; Minerva Paola Barrios-Ceballos ; Fern ; o Anaya-Velá ; zquez ; Kumiko Nakada-Tsukui ; Tomoyoshi Nozaki ; Felipe Padilla-Vaca
• 关键词：Entamoeba histolytica ; Sphingomyelinase ; Ceramide ; Scyphostatin
• 刊名：Experimental Parasitology
• 出版年：2010
• 出版时间：July 2010
• 年：2010
• 卷：125
• 期：3
• 页码：279-285
• 全文大小：1294 K

文摘

A novel neutral sphingomyelinase (nSMase) was characterized in Entamoeba histolytica trophozoites. SMase, a sphingomyelin-specific form of phospholipase C, catalyzes the hydrolysis of sphingomyelin to ceramide and phosphorylcholine. Three amebic putative nSMase genes were found to be actively transcribed. Mg²⁺-independent nSMase activity in the soluble fraction of the trophozoites was stimulated by Mn²⁺ and partially inhibited by Zn²⁺. nSMase activity of the recombinant protein EhnSM1, increased 4.5-fold in the presence of 0.5 mM Mn²⁺, and abolished by 5 mM Zn²⁺. A dose-dependent inhibition of rEhnSM1 was observed with scyphostatin, a specific inhibitor of nSMases. The EhnSM1 and EhnSM3 were detected in the soluble fraction of the amebic lysate as 35–37 kDa proteins by western blot analysis. Immunofluorescence assay showed that the overexpressed HA-tagged EhnSM1 and EhnSM3 were localized to the cytosol. The biological role of these novel E. histolytica nSMases described in this work remains to be determined.