Phylogeny to function: PE/PPE protein evolution and impact on Mycobacterium tuberculosis pathogenicity. Issue 5 (30th March 2015)

• Record Type: Journal Article
• Authors: Fishbein, S.; van Wyk, N.; Warren, R. M.; Sampson, S. L.
• Is Part Of: Molecular microbiology. Volume 96:Issue 5(2015)
• Page Start: 901
• Page End: 916
• Publication Date: 2015-03-30
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12981
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>The <italic>pe/ppe</italic> genes represent one of the most intriguing aspects of the <italic>M</italic><italic>ycobacterium tuberculosis</italic> genome. These genes are especially abundant in pathogenic mycobacteria, with more than 160 members in <italic>M</italic><italic>. tuberculosis</italic>. Despite being discovered over 15 years ago, their function remains unclear, although various lines of evidence implicate selected family members in mycobacterial virulence. In this review, we use PE/PPE phylogeny as a framework within which we examine the diversity and putative functions of these proteins. We report on the evolution and diversity of the respective gene families, as well as the implications thereof for function and host immune recognition. We summarize recent findings on <italic>pe/ppe</italic> gene regulation, also placing this in the context of PE/PPE phylogeny. We collate data from several large proteomics datasets, providing an overview of PE/PPE localization, and discuss the implications this may have for host responses. Assessment of the current knowledge of PE/PPE diversity suggests that these proteins are not variable antigens as has been so widely speculated; however, they do clearly play important roles in virulence. Viewing the growing body of <italic>pe/ppe</italic> literature through the lens of phylogeny reveals trends in features and function that may be associated with the evolution of mycobacterial pathogenicity.</p> </abstract>