TitleThe Mycobacterium avium ESX-5 PPE protein, PPE25-MAV, interacts with an ESAT-6 family Protein, MAV_2921, and localizes to the bacterial surface.
Publication TypeJournal Article
Year of Publication2012
AuthorsMcNamara, M, Danelishvili, L, Bermudez, LE
JournalMicrob Pathog
Date Published2012 Apr
KeywordsAmino Acid Motifs, Bacterial Proteins, Cell Membrane, Mycobacterium avium, Protein Binding, Protein Transport

Previous research has demonstrated that inactivation of the Mycobacterium avium gene, PPE25-MAV (MAV_2928), leads to a significant attenuation of virulence in both in vitro and in vivo models. PPE25-MAV encodes for a PPE family protein, a family from which many members have been implicated in both bacterial virulence and host immune recognition. Recent research has shown that many PPE family proteins are exported by a specialized Type VII secretion system in mycobacteria. In this context, the mechanisms of PPE25-MAV in M. avium pathogenesis were investigated. A mycobacterial 2-hybrid system was used to perform a directed search for M. avium proteins that interact directly with PPE25-MAV. An interaction was observed between PPE25-MAV and the ESAT-6 family protein, MAV_2921, and was further defined by 2-hybrid analysis of truncated PPE25-MAV, and confirmed by co-immunoprecipitation. Localization of the PPE25-MAV protein was analyzed in Mycobacterium smegmatis expressing the recombinant protein and a significant percentage of PPE25-MAV was shown to be exposed at the bacterial surface by surface biotinylation and trypsin protection assays. Finally, transcriptional analysis of PPE25-MAV and its associated operon suggested that nutrient limitation, a condition which occurs in the phagosome, plays a role in regulating expression of the PPE25-MAV gene.

Alternate JournalMicrob Pathog
PubMed ID22265661
PubMed Central IDPMC3883564
Grant ListP30 ES000210 / ES / NIEHS NIH HHS / United States
R01 AI043199 / AI / NIAID NIH HHS / United States
41399 / / PHS HHS / United States