Zinc regulates the activity of kinase-phosphatase pair (BasPrkC/BasPrpC) in Bacillus anthracis

Abstract

Bacillus anthracis Ser/Thr protein kinase PrkC (BasPrkC) is important for virulence of the bacterium within the host. Homologs of PrkC and its cognate phosphatase PrpC (BasPrpC) are the most conserved mediators of signaling events in diverse bacteria. BasPrkC homolog in Bacillus subtilis regulates critical processes like spore germination and BasPrpC modulates the activity of BasPrkC by dephosphorylation. So far, biochemical and genetic studies have provided important insights into the roles of BasPrkC and BasPrpC; however, regulation of their activities is not known. We studied the regulation of BasPrkC/BasPrpC pair and observed that Zn(2+) metal ions can alter their activities. Zn(2+) promotes BasPrkC kinase activity while inhibits the BasPrpC phosphatase activity. Concentration of Zn(2+) in growing B. anthracis cells was found to vary with growth phase. Zn(2+) was found to be lowest in log phase cells while it was highest in spores. This variation in Zn(2+) concentration is significant for understanding the antagonistic activities of BasPrkC/BasPrpC pair. Our results also show that BasPrkC activity is modulated by temperature changes and kinase inhibitors. Additionally, we identified Elongation Factor Tu (BasEf-Tu) as a substrate of BasPrkC/BasPrpC pair and assessed the impact of their regulation on BasEf-Tu phosphorylation. Based on these results, we propose Zn(2+) as an important regulator of BasPrkC/BasPrpC mediated phosphorylation cascades. Thus, this study reveals additional means by which BasPrkC can be activated leading to autophosphorylation and substrate phosphorylation.

Ser/Thr protein kinase PrkC-mediated regulation of GroEL is critical for biofilm formation in Bacillus anthracis

“…Ef-Tu that has previously been shown to be phosphorylated by PrkC (and homologs) in B. anthracis , Bacillus subtilis ( B. subtilis ), and M. tuberculosis was used as a positive control to corroborate our results. 14, 20, 21, 29 The experiment confirmed phosphorylation of SodA2, Ef-G, and GroEL by PrkC (Fig. 2, S3).…”

“…PrkC-K40M mutant was used as negative control, which is incapable of carrying out phosphorylation. 14, 15 Subsequently, to test the reversibility of phosphorylation, phosphorylated GroEL was incubated with PrpC, which led to its dephosphorylation (Fig. 2d).…”

“…15, 16 PrkC is capable of transducing signals efficiently during environmental stress conditions and has been proposed to function even in the spores. 14, 17 …”

Systematic Analysis of Mycobacterial Acylation Reveals First Example of Acylation-mediated Regulation of Enzyme Activity of a Bacterial Phosphatase

“…For other proteins, homology modeling was performed as described earlier (53,54). The templates were chosen for each protein, Rv1436 (PDB code 1VC2), Rv1437 (PDB code 1V6S), and Rv2889c (PDB code 1EFU), based on the sequence identities of 61, 49, and 39%, respectively.…”

Association between Field Liming and the Epidemic of Type 1 Diabetes

“…Zinc promotes kinase activity and inhibits phosphatase activity. [24,33] In the neonatal period there is enhanced beta-cell remodelling associated with beta-cell apoptosis and enhanced beta-cell specific antigen release. [34] This may trigger T1D by previously described manner.…”