Authors: Balakota Reddy Patakottu Prashant Kumar Singh Pawan Malhotra V S Chauhan Swati Patankar
Publish Date: 2011/06/04
Volume: 39, Issue: 3, Pages: 2225-2232
Abstract
Regulation of gene expression in the malaria parasite Plasmodium falciparum is tightly controlled and little is known about the many steps involved One step ie translation initiation is also poorly understood and in P falciparum choice of the translation initiation site TIS is a critical decision largely due to the high frequency of AUGs in the relatively long 5′ untranslated regions of parasite mRNAs The sequences surrounding the TIS have a major role to play in translation initiation and this report evaluates these sequences by mutational analysis of the heat shock protein 86 gene transient transfection and reporter assays in the parasite We find that purines at the −3 and +4 positions are essential for efficient translation in P falciparum similar to other eukaryotes Interestingly a U at the −1 position results in 25fold higher reporter activity compared to wild type Certain classes of protein biosynthetic genes show higher frequencies of U at the −1 position suggesting that these genes may exhibit higher levels of translation This work defines the optimal sequences for TIS choice and has implications for the design of efficient expression vectors in an important human pathogenBRP and PKS acknowledge the Indian Institute of Technology Bombay and the Council of Scientific and Industrial Research CSIR for their PhD fellowships SP acknowledges the Board for Research in Nuclear Sciences BRNS for funding granted to this project PM group is financially supported by the International Centre for Genetic Engineering and Biotechnology ICGEB and the Department of Biotechnology DBT We thank Drs Kevin Militello and Dyann Wirth Harvard School of Public Health for sharing the Pf86 and Renilla luciferase vectors We also thank the reviewers of the manuscript for their careful reading of the manuscript and excellent suggestions for improvement
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