https://scholars.lib.ntu.edu.tw/handle/123456789/506737
標題: | DNA topoisomerase IIIβ promotes cyst generation by inducing cyst wall protein gene expression in Giardia lamblia | 作者: | CHIN-HUNG SUN Weng S.-C. Wu J.-H. Tung S.-Y. Su L.-H. Lin M.-H. Lee G.A. |
關鍵字: | Cyst; Differentiation; DNA-binding protein; Giardia; Topoisomerase IIIβ; Transcription | 公開日期: | 2020 | 出版社: | Royal Society Publishing | 卷: | 10 | 期: | 2 | 起(迄)頁: | 190228 | 來源出版物: | Open Biology | 摘要: | Giardia lamblia causes waterborne diarrhoea by transmission of infective cysts. Three cyst wall proteins are highly expressed in a concerted manner during encystation of trophozoites into cysts. However, their gene regulatory mechanism is still largely unknown. DNA topoisomerases control topological homeostasis of genomic DNA during replication, transcription and chromosome segregation. They are involved in a variety of cellular processes including cell cycle, cell proliferation and differentiation, so they may be valuable drug targets. Giardia lamblia possesses a type IA DNA topoisomerase (TOP3β) with similarity to the mammalian topoisomerase IIIβ. We found that TOP3β was upregulated during encystation and it possessed DNA-binding and cleavage activity. TOP3β can bind to the cwp promoters in vivo using norfloxacin-mediated topoisomerase immunoprecipitation assays. We also found TOP3β can interact with MYB2, a transcription factor involved in the coordinate expression of cwp1-3 genes during encystation. Interestingly, overexpression of TOP3β increased expression of cwp1-3 and myb2 genes and cyst formation. Microarray analysis confirmed upregulation of cwp1-3 and myb2 genes by TOP3β. Mutation of the catalytically important Tyr residue, deletion of C-terminal zinc ribbon domain or further deletion of partial catalytic core domain reduced the levels of cleavage activity, cwp1-3 and myb2 gene expression, and cyst formation. Interestingly, some of these mutant proteins were mis-localized to cytoplasm. Using a CRISPR/Cas9 system for targeted disruption of top3β gene, we found a significant decrease in cwp1-3 and myb2 gene expression and cyst number. Our results suggest that TOP3β may be functionally conserved, and involved in inducing Giardia cyst formation. ? 2020 The Authors. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078968619&doi=10.1098%2frsob.190228&partnerID=40&md5=9af61688eb9b0784ac820b923b2c37da https://scholars.lib.ntu.edu.tw/handle/123456789/506737 |
ISSN: | 2046-2441 | DOI: | 10.1098/rsob.190228 | SDG/關鍵字: | DNA topoisomerase; Myb2 protein, Giardia lamblia; protozoal protein; transactivator protein; cell wall; chemistry; DNA microarray; enzyme active site; enzymology; gene expression profiling; gene expression regulation; genetics; Giardia intestinalis; metabolism; mutation; physiology; procedures; promoter region; upregulation; Catalytic Domain; Cell Wall; DNA Topoisomerases, Type I; Gene Expression Profiling; Gene Expression Regulation; Giardia lamblia; Mutation; Oligonucleotide Array Sequence Analysis; Promoter Regions, Genetic; Protozoan Proteins; Trans-Activators; Up-Regulation |
顯示於: | 醫學系 |
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