Impact of Serine/Threonine Protein Kinases on the Regulation of Sporulation in Bacillus subtilis

Abstract

Bacteria possess many kinases that catalyze phosphorylation of proteins on diverse amino acids including arginine, cysteine, histidine, aspartate, serine, threonine, and tyrosine. These protein kinases regulate different physiological processes in response to environmental modifications. For example, in response to nutritional stresses, the Gram-positive bacterium Bacillus subtilis can differentiate into an endospore; the initiation of sporulation is controlled by the master regulator Spo0A, which is activated by phosphorylation. Spo0A phosphorylation is carried out by a multi-component phosphorelay system. These phosphorylation events on histidine and aspartate residues are labile, highly dynamic and permit a temporal control of the sporulation initiation decision. More recently, another kind of phosphorylation, more stable yet still dynamic, on serine or threonine residues, was proposed to play a role in spore maintenance and spore revival. Kinases that perform these phosphorylation events mainly belong to the Hanks family and could regulate spore dormancy and spore germination. The aim of this mini review is to focus on the regulation of sporulation in B. subtilis by these serine and threonine phosphorylation events and the kinases catalyzing them.

Neurotoxin synthesis is positively regulated by the sporulation transcription factor Spo0A in Clostridium botulinum type E

“…4B). Hence, sporulation is likely to cause optical density declines through mother cell lysis (Carvalho et al, 2010;Pompeo et al, 2016).…”

The serine/threonine kinase Stk and the phosphatase Stp regulate cell wall synthesis in Staphylococcus aureus

“…Furthermore, Stk cross-talks with two-component systems involved in cell wall metabolism by phosphorylation of the response regulator of VraTSR 8 , WalRK 9 and GraSR 24 , affecting the expression of the cell wall stimulon and cell wall hydrolases as well as the cell wall charge. There are also studies which have shown that Stk homologs regulate cell wall synthesis and cell division in Streptococcus 25 – 28 , Bacillus 29 , 30 , Enterococcus 31 and Streptomyces 32 .…”

Modulators of Enterococcus faecalis Cell Envelope Integrity and Antimicrobial Resistance Influence Stable Colonization of the Mammalian Gastrointestinal Tract

“…IreK is a transmembrane protein exhibiting a conserved domain architecture comprised of an intracellular eukaryote-like Ser/Thr kinase domain and extracellular PASTA domains, defining it as a member of the PASTA kinase family. PASTA kinases are conserved across the Firmicutes phylum and are involved in various fundamental processes, such as sporulation (14,15), energy metabolism (16,17), and cell wall homeostasis (16,18). Although the function of the PASTA domains is not well understood, they are thought to sense cell wall stress (15,19).…”