THE CPSBCD TYROSINE KINASE SYSTEM IN S.PNEUMONIAE

Abstract

The capsular polysaccharide (CPS) serves as the outermost protective layer of bacteria, preventing opsonophagocytosis clearance. Streptococcus pneumoniae adapts to diverse host environments by regulating CPS through the bacterial tyrosine kinase system, CpsBCD. This study demonstrates that CpsCD is essential for bacterial growth. Deletion of CpsCD leads to the accumulation of low molecular weight CPS and subsequent cell lysis. CpsC modulates CPS length through interactions with CpsH, while chain length is further influenced by the phosphorylation of CpsD. Furthermore, this study reveals the importance of CpsCD in coordinating CPS synthesis with peptidoglycan synthesis at the mid-cell. CpsC is among the first CPS enzymes recruited to the mid-cell through the divisome and determines the site of CPS synthesis. Future research will aim to identify phosphorylation triggers, evaluate the role of CPS chain length in infection, and elucidate interactions between CpsC, other CPS enzymes, and cell division proteins. Comprehending CPS synthesis is pivotal for therapeutic targets, vaccines, and gaining insights into bacterial pathogenesis.