Comparative Phosphoproteomics Reveals the Role of AmpC β-lactamase Phosphorylation in the Clinical Imipenem-resistant Strain Acinetobacter baumannii SK17
| Autor: | Chi-Chi Chou, Te-Li Chen, Shih-Hsiung Wu, Suh-Yuen Liang, Jeffy Chern, Jiahn-Haur Liao, Shih-Feng Tsai, Wan-Ling Wu, Juo-Hsin Lai, Jhih-Tian Yang |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Acinetobacter baumannii Models Molecular Proteomics Imipenem Proteome medicine.drug_class Antibiotics medicine.disease_cause Biochemistry beta-Lactam Resistance beta-Lactamases Analytical Chemistry Microbiology 03 medical and health sciences Antibiotic resistance Bacterial Proteins Mutant protein Tandem Mass Spectrometry medicine Humans Phosphorylation Molecular Biology Cross Infection Binding Sites biology Research Phosphoproteomics Pathogenic bacteria biology.organism_classification Phosphoproteins Anti-Bacterial Agents Protein Structure Tertiary 030104 developmental biology Mutation Bacteria medicine.drug |
| Zdroj: | Molecularcellular proteomics : MCP. 15(1) |
| ISSN: | 1535-9484 |
| Popis: | Nosocomial infectious outbreaks caused by multidrug-resistant Acinetobacter baumannii have emerged as a serious threat to human health. Phosphoproteomics of pathogenic bacteria has been used to identify the mechanisms of bacterial virulence and antimicrobial resistance. In this study, we used a shotgun strategy combined with high-accuracy mass spectrometry to analyze the phosphoproteomics of the imipenem-susceptible strain SK17-S and -resistant strain SK17-R. We identified 410 phosphosites on 248 unique phosphoproteins in SK17-S and 285 phosphosites on 211 unique phosphoproteins in SK17-R. The distributions of the Ser/Thr/Tyr/Asp/His phosphosites in SK17-S and SK17-R were 47.0%/27.6%/12.4%/8.0%/4.9% versus 41.4%/29.5%/17.5%/6.7%/4.9%, respectively. The Ser-90 phosphosite, located on the catalytic motif S(88)VS(90)K of the AmpC β-lactamase, was first identified in SK17-S. Based on site-directed mutagenesis, the nonphosphorylatable mutant S90A was found to be more resistant to imipenem, whereas the phosphorylation-simulated mutant S90D was sensitive to imipenem. Additionally, the S90A mutant protein exhibited higher β-lactamase activity and conferred greater bacterial protection against imipenem in SK17-S compared with the wild-type. In sum, our results revealed that in A. baumannii, Ser-90 phosphorylation of AmpC negatively regulates both β-lactamase activity and the ability to counteract the antibiotic effects of imipenem. These findings highlight the impact of phosphorylation-mediated regulation in antibiotic-resistant bacteria on future drug design and new therapies. |
| Databáze: | OpenAIRE |
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