Journal Article

Phosphothreonine Lyase Activity of a Bacterial Type III Effector Family

Zhou, Yan, Xu, Hao, Shao, Feng, Zhou, Jian-Min, Li, Hongtao, Long, Chengzu, Chen, She, Zhang, Jie, Li, Shuqin

2007

Overview

Pathogenic bacteria use the type III secretion system to deliver effector proteins into host cells to modulate the host signaling pathways. In this study, the Shigella type III effector OspF was shown to inactivate mitogen-activated protein kinases (MAPKs) [extracellular signal-regulated kinases 1 and 2 (Erk1/2), c-Jun N-terminal kinase, and p38]. OspF irreversibly removed phosphate groups from the phosphothreonine but not from the phosphotyrosine residue in the activation loop of MAPKs. Mass spectrometry revealed a mass loss of 98 daltons in p-Erk2, due to the abstraction of the α proton concomitant with cleavage of the C-OP bond in the phosphothreonine residue. This unexpected enzymatic activity, termed phosphothreonine lyase, appeared specific for MAPKs and was shared by other OspF family members.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Amino Acid Sequence / Animals / Bacteria / Bacterial Proteins - genetics / Bacterial Proteins - metabolism / Bacteriology / Biochemistry / Biological and medical sciences / Cell Line / Chemical bonding / Enzymatic activity / enzyme activity / Enzymes / Family members / Fundamental and applied biological sciences. Psychology / HeLa Cells / Humans / Immunoblotting / Infections / JNK Mitogen-Activated Protein Kinases - antagonists & inhibitors / JNK Mitogen-Activated Protein Kinases - metabolism / Kinases / MAP Kinase Signaling System / Mass spectrometry / Mass spectroscopy / Microbiology / mitogen-activated protein kinase / Mitogen-Activated Protein Kinase 1 - antagonists & inhibitors / Mitogen-Activated Protein Kinase 1 - metabolism / Mitogen-Activated Protein Kinase 3 - antagonists & inhibitors / Mitogen-Activated Protein Kinase 3 - metabolism / Mitogen-Activated Protein Kinases - antagonists & inhibitors / Mitogen-Activated Protein Kinases - metabolism / Molecular Sequence Data / Mutagenesis / NF-kappa B - metabolism / p38 Mitogen-Activated Protein Kinases - antagonists & inhibitors / p38 Mitogen-Activated Protein Kinases - metabolism / Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains / Pathogens / Phosphatases / Phosphates / Phosphoprotein Phosphatases - metabolism / Phosphorylation / Salmonella typhimurium / Shigella / Shigella flexneri - metabolism / Shigella flexneri - physiology / signal transduction / Spectrum analysis / type III secretion system / Tyrosine - metabolism