Δp>24 (25)p>-sterol methenyltransferase: Intracellular localization and azasterol sensitivity in Leishmania major promastigotes overexpressing the enzyme

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• 作者：Carmen Jim&#xe9 ; nez-Jim&#xe9 ; nez ; Juana Carrero-L&#xe9 ; rida ; Marco Sealey-Cardona ; Luis Miguel Ruiz P&#xe9 ; rez ; Julio Alberto Urbina ; Dolores Gonz&#xe1 ; lez Pacanowska
• 关键词：Leishmania ; Endoplasmic reticulum ; Sterol methyltransferase
• 刊名：Molecular and Biochemical Parasitology
• 出版年：2008
• 期刊代码：108_01666851
• 类别：bio
• 出版时间：July 2008
• 卷：160
• 期：1
• 页码：52-59
• 文件大小：885 K

摘要

Trypanosomatids contain predominantly ergostane-based sterols, which differ from cholesterol, the main sterol in mammalian cells, in the presence of a methyl group in the 24 position. The methylation is initiated by S-adenosyl-pan class="smCaps">lpan>-methionine:Δp>24 (25)p>-sterol methenyltransferase, an enzyme present in protozoa, but absent in mammals. The importance of this enzyme is underscored by its potential as a drug target in the treatment of the leishmaniases. Here, we report studies concerning the intracellular distribution of sterol methenyltransferase in Leishmania major promastigotes and overexpressing cells using a specific antibody raised against highly purified recombinant protein. It was found by immunofluorescence and electron microscopy studies that in L. major wild-type cells sterol methenyltransferase was primarily associated to the endoplasmic reticulum. In addition to this location, the protein was incorporated into translucent vesicles presumably of the endocytic pathway. We also found in this study that cells overproducing the enzyme do not have increased resistance to the sterol methenyltransferase inhibitor 22, 26 azasterol.