The juxtamembrane domain of StkP is phosphorylated and influences cell division in Streptococcus pneumoniae

• DOI: 10.1128/mbio.03799-24
• Publication Date: 2025-04-08T13:09:43Z
• Authors: Mélisse Hamidi; Sathya Narayanan ...; Vaishnavi Ravikumar; Virginie Gueguen-...; Cédric Laguri; Céline Freton; Ivan Mijakovic; Jean-Pierre Simorre; Stéphanie Ravaud; Christophe Grange...
• Keywords: Cell Physiology

ABSTRACT Eukaryotic-like membrane Ser/Thr protein kinases play a pivotal role in different aspects of bacterial physiology. In contrast to the diversity their extracellular domains, cytoplasmic catalytic domains are highly conserved. However, function long juxtamembrane domain (JMD), which connects transmembrane helix, remains elusive. this study, we investigated JMD kinase StkP cell division Streptococcus pneumoniae . We observed that deletion affected ability phosphorylate some its endogenous substrates, thereby resulting significant morphogenesis defects. Furthermore, multiple threonine residues were identified as being phosphorylated JMD. To investigate functional significance these phosphorylation sites, conducted an integrative analysis, combining structural biology, proteomics, and imaging. Our results revealed did not perturb substrates. it modulated timing localization septum dynamics constriction. further demonstrated facilitated recruitment several proteins, suggesting is required assemble machinery at septum. conclusion, study demonstrates by critical for S. These observations may serve model understanding regulatory other kinases. IMPORTANCE How serine/threonine activated debated. particular, models rely on made with eukaryotic counterparts, only few studies have molecular activation mechanism This particularly case regard proposed contribute numerous likely essential Rather, our findings reveal division, where affects assembly allow us assign StkP-mediated regulation pneumococcal providing new avenue contribution physiology bacteria.