1
|
Singh KK, Athira PJ, Bhardwaj N, Singh DP, Watson U, Saini DK. Acetylation of Response Regulator Protein MtrA in M. tuberculosis Regulates Its Repressor Activity. Front Microbiol 2021; 11:516315. [PMID: 33519719 PMCID: PMC7843721 DOI: 10.3389/fmicb.2020.516315] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 12/17/2020] [Indexed: 11/13/2022] Open
Abstract
MtrA is an essential response regulator (RR) protein in M. tuberculosis, and its activity is modulated after phosphorylation from its sensor kinase MtrB. Interestingly, many regulatory effects of MtrA have been reported to be independent of its phosphorylation, thereby suggesting alternate mechanisms of regulation of the MtrAB two-component system in M. tuberculosis. Here, we show that RR MtrA undergoes non-enzymatic acetylation through acetyl phosphate, modulating its activities independent of its phosphorylation status. Acetylated MtrA shows increased phosphorylation and enhanced interaction with SK MtrB assessed by phosphotransfer assays and FRET analysis. We also observed that acetylated MtrA loses its DNA-binding ability on gene targets that are otherwise enhanced by phosphorylation. More interestingly, acetylation is the dominant post-translational modification, overriding the effect of phosphorylation. Evaluation of the impact of MtrA and its lysine mutant overexpression on the growth of H37Ra bacteria under different conditions along with the infection studies on alveolar epithelial cells further strengthens the importance of acetylated MtrA protein in regulating the growth of M. tuberculosis. Overall, we show that both acetylation and phosphorylation regulate the activities of RR MtrA on different target genomic regions. We propose here that, although phosphorylation-dependent binding of MtrA drives its repressor activity on oriC and rpf, acetylation of MtrA turns this off and facilitates division in mycobacteria. Our findings, thus, reveal a more complex regulatory role of RR proteins in which multiple post-translational modifications regulate the activities at the levels of interaction with SK and the target gene expression.
Collapse
Affiliation(s)
- Krishna Kumar Singh
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - P J Athira
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Neerupma Bhardwaj
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, India
| | - Devendra Pratap Singh
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Uchenna Watson
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India.,Department of Studies in Zoology, University of Mysore, Mysore, India
| | - Deepak Kumar Saini
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India.,Centre for Biosystems Science and Engineering, Indian Institute of Science, Bengaluru, India
| |
Collapse
|
2
|
Xie M, Wu M, Han A. Structural insights into the signal transduction mechanism of the K +-sensing two-component system KdpDE. Sci Signal 2020; 13:13/643/eaaz2970. [PMID: 32753477 DOI: 10.1126/scisignal.aaz2970] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Two-component systems (TCSs), which consist of a histidine kinase (HK) sensor and a response regulator (RR), are important for bacteria to quickly sense and respond to various environmental signals. HKs and RRs typically function as a cognate pair, interacting only with one another to transduce signaling. Precise signal transduction in a TCS depends on the specific interactions between the receiver domain (RD) of the RR and the dimerization and histidine phosphorylation domain (DHp) of the HK. Here, we determined the complex structure of KdpDE, a TCS consisting of the HK KdpD and the RR KdpE, which is responsible for K+ homeostasis. Both the RD and the DNA binding domain (DBD) of KdpE interacted with KdpD. Although the RD of KdpE and the DHp of KdpD contributed to binding specificity, the DBD mediated a distinct interaction with the catalytic ATP-binding (CA) domain of KdpD that was indispensable for KdpDE-mediated signal transduction. Moreover, the DBD-CA interface largely overlapped with that of the DBD-DNA complex, leading to competition between KdpD and its target promoter in a KdpE phosphorylation-dependent manner. In addition, the extended C-terminal tail of the CA domain was critical for stabilizing the interaction with KdpDE and for signal transduction. Together, these data provide a molecular basis for specific KdpD and KdpE interactions that play key roles in efficient signal transduction and transcriptional regulation by this TCS.
Collapse
Affiliation(s)
- Mingquan Xie
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Mengyuan Wu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Aidong Han
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China.
| |
Collapse
|
3
|
Sarva K, Satsangi AT, Plocinska R, Madiraju M, Rajagopalan M. Two-component kinase TrcS complements Mycobacterium smegmatis mtrB kinase mutant. Tuberculosis (Edinb) 2019; 116S:S107-S113. [PMID: 31088763 DOI: 10.1016/j.tube.2019.04.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 11/21/2018] [Indexed: 10/26/2022]
Abstract
MtrAB is one of the important two-component regulatory systems (2CRS) in mycobacteria and consists of MtrB sensor kinase and MtrA response regulator. Mycobacterium smegmatis mtrB mutant is filamentous and shows defects in cell division, cell shape and optimal expression of the MtrA-regulon. In an effort to identify M. tuberculosis sensor kinases that work with MtrA and/or bypass the need for MtrB, we attempted to overexpress other M. tuberculosis sensor kinases in M. smegmatis mtrB background and reverse the mtrB phenotype. Overexpression of trcS kinase, but not nine others tested, reversed the mtrB mutant phenotype including the expression of the MtrA-regulon. However, the overexpression of trcS kinase did not reverse the mutant phenotype of a mtrA mutant. Bacterial-two hybrid assays revealed that the TrcS kinase interacts with both MtrB kinase and the response regulator MtrA. Recombinant TrcS protein exhibits autophosphorylation and transphosphorylation of its cognate response regulator TrcR, and MtrA. Together, these results support a model involving cross-talk between the MtrAB and TrcRS two-component systems.
Collapse
Affiliation(s)
- Krishna Sarva
- The University of Health Science Center @ Tyler, Tyler, TX, 75708, USA
| | | | - Renata Plocinska
- The University of Health Science Center @ Tyler, Tyler, TX, 75708, USA
| | - Murty Madiraju
- The University of Health Science Center @ Tyler, Tyler, TX, 75708, USA
| | | |
Collapse
|
4
|
Yuan LM, Gao ZZ, Sun HY, Qian SN, Xiao YS, Sun LL, Zeng S. Inter-isoform Hetero-dimerization of Human UDP-Glucuronosyltransferases (UGTs) 1A1, 1A9, and 2B7 and Impacts on Glucuronidation Activity. Sci Rep 2016; 6:34450. [PMID: 27857056 PMCID: PMC5114717 DOI: 10.1038/srep34450] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/13/2016] [Indexed: 11/24/2022] Open
Abstract
Human UDP-glucuronosyltransferases (UGTs) play a pivotal role in phase II metabolism by catalyzing the glucuronidation of endobiotics and xenobiotics. The catalytic activities of UGTs are highly impacted by both genetic polymorphisms and oligomerization. The present study aimed to assess the inter-isoform hetero-dimerization of UGT1A1, 1A9, and 2B7, including the wild type (1A1*1, 1A9*1, and 2B7*1) and the naturally occurring (1A1*1b, 1A9*2/*3/*5, and 2B7*71S/*2/*5) variants. The related enzymes were double expressed in Bac-to-Bac systems. The fluorescence resonance energy transfer (FRET) technique and co-immunoprecipitation (Co-IP) revealed stable hetero-dimerization of UGT1A1, 1A9, and 2B7 allozymes. Variable FRET efficiencies and donor-acceptor distances suggested that genetic polymorphisms resulted in altered affinities to the target protein. In addition, the metabolic activities of UGTs were differentially altered upon hetero-dimerization via double expression systems. Moreover, protein interactions also changed the regioselectivity of UGT1A9 for querectin glucuronidation. These findings provide in-depth understanding of human UGT dimerization as well as clues for complicated UGT dependent metabolism in humans.
Collapse
Affiliation(s)
- Ling-Min Yuan
- Institute of Drug Metabolism and Pharmaceutical Analysis, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Zhang-Zhao Gao
- Institute of Drug Metabolism and Pharmaceutical Analysis, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Hong-Ying Sun
- Institute of Drug Metabolism and Pharmaceutical Analysis, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Sai-Nan Qian
- Institute of Drug Metabolism and Pharmaceutical Analysis, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yong-Sheng Xiao
- Institute of Drug Metabolism and Pharmaceutical Analysis, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Lian-Li Sun
- Institute of Drug Metabolism and Pharmaceutical Analysis, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Su Zeng
- Institute of Drug Metabolism and Pharmaceutical Analysis, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| |
Collapse
|