Polyamine synthesis effects capsule expression in Streptococcus pneumoniae TIGR4

Purpose: We recently reported that isogenic deletion of lysine decarboxylase (?cadA/SP_0916), an enzyme that catalyzes the biosynthesis of polyamine cadaverine in Streptococcus pneumoniae TIGR4 results in loss of capsular polysaccharide (CPS), which constitutes a novel mechanism of regulation of CPS. Here, we conducted RNA-Seq to elucidate molecular mechanisms of CPS regulation in polyamine synthesis impaired pneumococci. Result: Significantly differentially expressed genes in ?cadA represent pneumococcal pathways involved in the biosynthesis of precursors for CPS and peptidoglycan. Conclusion: We establish a possible link and interchange between two cellular processes such as high energy demanding capsule production and oxidative stress responses in polyamine synthesis impaired pneumococci (?cadA). Overall design: Comparing the gene expression changes between S. pneumoniae TIGR4 wild type and polyamine synthesis impaired isogenic deletion strain ?cadA.