Protein kinase B controls Mycobacterium tuberculosis growth via phosphorylation of the transcriptional regulator Lsr2 at threonine 112

Abstract

Summary Mycobacterium tuberculosis (Mtb) is able to persist in the body through months of multi‐drug therapy. Mycobacteria possess a wide range of regulatory proteins, including the protein kinase B (PknB) which controls peptidoglycan biosynthesis during growth. Here, we observed that depletion of PknB resulted in specific transcriptional changes that are likely caused by reduced phosphorylation of the H‐NS‐like regulator Lsr2 at threonine 112. The activity of PknB towards this phosphosite was confirmed with purified proteins, and this site was required for adaptation of Mtb to hypoxic conditions, and growth on solid media. Like H‐NS, Lsr2 binds DNA in sequence‐dependent and non‐specific modes. PknB phosphorylation of Lsr2 reduced DNA binding, measured by fluorescence anisotropy and electrophoretic mobility shift assays, and our NMR structure of phosphomimetic T112D Lsr2 suggests that this may be due to increased dynamics of the DNA‐binding domain. Conversely, the phosphoablative T112A Lsr2 had increased binding to certain DNA sites in ChIP‐sequencing, and Mtb containing this variant showed transcriptional changes that correspond with the change in DNA binding. In summary, PknB controls Mtb growth and adaptations to the changing host environment by phosphorylating the global transcriptional regulator Lsr2.

Xenogeneic silencing relies on temperature-dependent phosphorylation of the host H-NS protein in Shewanella

“…However, several attempts to delete SO_1461 were made at 30°C, but no deletion mutant was obtained, presumably because the gene may be essential in the presence of prophage CP4So. This result is consistent with the findings of earlier reports, which showed that the PknB was essential in M. tuberculosis ( 58 ) and that pknB can only be deleted in osmoprotective sucrose magnesium medium ( 59 ).…”

“…Recently, the importance of posttranslational modification of nucleoid-associated proteins in different bacteria has been reviewed ( 62 ). Several recent studies have examined the changes in the regulatory role of H-NS due to posttranslational modification ( 59 , 63 ). One study used proteomic analysis and found that phosphorylation of H-NS on Thr13 is important for upregulation of a wide range of genetic loci, including the PhoP/PhoQ-regulated genes in Salmonella enterica serovar Typhimurium ( 63 ).…”

“…One study used proteomic analysis and found that phosphorylation of H-NS on Thr13 is important for upregulation of a wide range of genetic loci, including the PhoP/PhoQ-regulated genes in Salmonella enterica serovar Typhimurium ( 63 ). Another study found four phosphorylated Thr residues of the H-NS analog in M. tuberculosis , and phosphorylation of Thr112 is required for M. tuberculosis to grow on solid media and to survive under hypoxic conditions ( 59 ). A recent study reported that the expression of foreign genes of Salmonella is activated inside macrophages through degradation of H-NS by the protease Lon ( 64 ).…”

The architects of bacterial DNA bridges: a structurally and functionally conserved family of proteins

“…Lsr2 of M. tuberculosis has been found to be phosphorylated at Thr112, located near the DNA-binding motif [155]. A recent study shows that phosphorylation of this residue decreases DNA binding by Lsr2, thus resulting in altered expression of genes important for M. tuberculosis growth and survival [156]. Some residues (Thr8, Thr22 and Thr31) in the N-terminal domain of Lsr2 were also found to be phosphorylated in vitro [156].…”

Alterations in the Cell Wall of Rhodococcus biphenylivorans Under Norfloxacin Stress

“…Moreover, the expression of rpfE , encoding a muralytic enzyme for the lysis and remodeling of peptidoglycan ( Sexton et al, 2015 ), was found to be relatively enhanced in VBNC cells comparing to the 16S gene ( Figure 5C ). While pknB , a protein kinase B gene, controlling the biosynthesis of peptidoglycan during cell growth ( Alqaseer et al, 2019 ), was found to be relatively high expression during the TG9 entry into VBNC ( Figure 5D ).…”