Influence of mutations in PPE38 on the secretome composition of M. tuberculosis

What is the influence of mutations in PPE38 on the secretome composition of M. tuberculosis? Certain clinical isolates of M. tuberculosis belonging to the Beijing lineage have mutations in ppe38 and this leads to a loss of secretion of the PE_PGRS substrates and hypervirulence in a mouse model of M. tuberculosis. Culture filtrates (secretomes) of 3 strains have been collected of which strain SAWC_2088 has intact PPE38 and Strains SAWC_2135 and SAWC_2701 have mutated PPE38. The strains with mutated PPE38 were also complemented by reintroducing the corresponding genes on an integrative plasmid. Label-free single-shot proteomics was used to profile protein expression in M. tuberculosis secretomes.