کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2829864 1163310 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The chitin biosynthesis pathway in Entamoeba and the role of glucosamine-6-P isomerase by RNA interference
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شناسی مولکولی
پیش نمایش صفحه اول مقاله
The chitin biosynthesis pathway in Entamoeba and the role of glucosamine-6-P isomerase by RNA interference
چکیده انگلیسی

Entamoeba histolytica, the causative agent of amoebiasis, infects through its cyst form. A thick chitin wall protects the cyst from the harsh environment outside of the body. It is known that chitin is synthesized only during encystation, but the chitin synthesis pathway (CSP) of Entamoeba is not well characterized. In this report, we have identified the genes involved in chitin biosynthesis from the Entamoeba genome database and verified their expression profile at the transcriptional level in encysting Entamoeba invadens. Semi-quantitative RT-PCR (sqRT-PCR) analysis showed that all the chitin pathway genes are entirely absent or transcribed at low levels in trophozoites. The mRNA expression of most of the CSP genes reached their maximum level between 9 and 12 h after the in vitro initiation of encystation. Double-stranded RNA-mediated silencing of glucosamine-6-P isomerase (Gln6Pi) reduced chitin synthesis to 62–64%, which indicates that Gln6Pi might be a key enzyme for regulating chitin synthesis in Entamoeba. The study of different enzymes involved in glycogen metabolism revealed that stored glycogen is converted to glucose during encystation. It is clear from the sqRT-PCR analysis that the rate of glycolysis decreases as encystation proceeds. Encystation up-regulates the expression of glycogen phosphorylase, which is responsible for glycogen degradation. The significant decrease in chitin synthesis in encysting cells treated with a specific inhibitor of glycogen phosphorylase indicates that the glucose obtained from the degradation of stored glycogen in trophozoites might be one of the major sources of glucose for chitin synthesis.

Figure optionsDownload high-quality image (138 K)Download as PowerPoint slideHighlights
► Gene silencing by RNA interference is established in Entamoeba invadens system for the first time.
► Expression of different genes of Entamoeba chitin synthesis pathway was validated.
► Glucosamine-6 P isomerase plays a vital role in chitin synthesis in Entamoeba.
► Stored glycogen disintegrates to glucose during chitin synthesis in encysting amoeba.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Molecular and Biochemical Parasitology - Volume 186, Issue 1, November 2012, Pages 60–68
نویسندگان
, ,