An HD-domain phosphodiesterase mediates cooperative hydrolysis of c-di-AMP to affect bacterial growth and virulence.

Abstract

The nucleotide cyclic di-3',5'- adenosine monophosphate (c-di-AMP) was recently identified as an essential and widespread second messenger in bacterial signaling. Among c-di-AMP-producing bacteria, altered nucleotide levels result in several physiological defects and attenuated virulence. Thus, a detailed molecular understanding of c-di-AMP metabolism is of both fundamental and practical interest. Currently, c-di-AMP degradation is recognized solely among DHH-DHHA1 domain-containing phosphodiesterases. Using chemical proteomics, we identified the Listeria monocytogenes protein PgpH as a molecular target of c-di-AMP. Biochemical and structural studies revealed that the PgpH His-Asp (HD) domain bound c-di-AMP with high affinity and specifically hydrolyzed this nucleotide to 5'-pApA. PgpH hydrolysis activity was inhibited by ppGpp, indicating a cross-talk between c-di-AMP signaling and the stringent response. Genetic analyses supported coordinated regulation of c-di-AMP levels in and out of the host. Intriguingly, a L. monocytogenes mutant that lacks c-di-AMP phosphodiesterases exhibited elevated c-di-AMP levels, hyperinduced a host type-I IFN response, and was significantly attenuated for infection. Furthermore, PgpH homologs, which belong to the 7TMR-HD family, are widespread among hundreds of c-di-AMP synthesizing microorganisms. Thus, PgpH represents a broadly conserved class of c-di-AMP phosphodiesterase with possibly other physiological functions in this crucial signaling network.

• Authors: TuAnh Ngoc Huynh, Shukun Luo, Daniel Pensinger, John-Demian Sauer, Liang Tong, Joshua J Woodward
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 112 Issue 7 Pg. E747-56 (Feb 17 2015) ISSN: 1091-6490 [Electronic] United States
• PMID: 25583510 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Cyclic AMP
• Phosphoric Diester Hydrolases

Topics

• Amino Acid Sequence
• Cyclic AMP (metabolism)
• Hydrolysis
• Listeria monocytogenes (enzymology, growth & development, pathogenicity)
• Models, Molecular
• Molecular Sequence Data
• Phosphoric Diester Hydrolases (chemistry, metabolism)
• Protein Binding
• Virulence