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Roy TB, Sarma SP. Insights into the solution structure and transcriptional regulation of the MazE9 antitoxin in Mycobacterium tuberculosis. Proteins 2023. [PMID: 37737533 DOI: 10.1002/prot.26589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 08/21/2023] [Accepted: 09/07/2023] [Indexed: 09/23/2023]
Abstract
The present study endeavors to decode the details of the transcriptional autoregulation effected by the MazE9 antitoxin of the Mycobacterium tuberculosis MazEF9 toxin-antitoxin system. Regulation of this bicistronic operon at the level of transcription is a critical biochemical process that is key for the organism's stress adaptation and virulence. Here, we have reported the solution structure of the DNA binding domain of MazE9 and scrutinized the thermodynamic and kinetic parameters operational in its interaction with the promoter/operator region, specific to the mazEF9 operon. A HADDOCK model of MazE9 bound to its operator DNA has been calculated based on the information on interacting residues obtained from these studies. The thermodynamics and kinetics of the interaction of MazE9 with the functionally related mazEF6 operon indicate that the potential for intracellular cross-regulation is unlikely. An interesting feature of MazE9 is the cis ⇌ trans conformational isomerization of proline residues in the intrinsically disordered C-terminal domain of this antitoxin.
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Affiliation(s)
- Tanaya Basu Roy
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Siddhartha P Sarma
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
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Coluccino G, Muraca VP, Corazza A, Lippe G. Cyclophilin D in Mitochondrial Dysfunction: A Key Player in Neurodegeneration? Biomolecules 2023; 13:1265. [PMID: 37627330 PMCID: PMC10452829 DOI: 10.3390/biom13081265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/11/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Mitochondrial dysfunction plays a pivotal role in numerous complex diseases. Understanding the molecular mechanisms by which the "powerhouse of the cell" turns into the "factory of death" is an exciting yet challenging task that can unveil new therapeutic targets. The mitochondrial matrix protein CyPD is a peptidylprolyl cis-trans isomerase involved in the regulation of the permeability transition pore (mPTP). The mPTP is a multi-conductance channel in the inner mitochondrial membrane whose dysregulated opening can ultimately lead to cell death and whose involvement in pathology has been extensively documented over the past few decades. Moreover, several mPTP-independent CyPD interactions have been identified, indicating that CyPD could be involved in the fine regulation of several biochemical pathways. To further enrich the picture, CyPD undergoes several post-translational modifications that regulate both its activity and interaction with its clients. Here, we will dissect what is currently known about CyPD and critically review the most recent literature about its involvement in neurodegenerative disorders, focusing on Alzheimer's Disease and Parkinson's Disease, supporting the notion that CyPD could serve as a promising therapeutic target for the treatment of such conditions. Notably, significant efforts have been made to develop CyPD-specific inhibitors, which hold promise for the treatment of such complex disorders.
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Affiliation(s)
- Gabriele Coluccino
- Department of Medicine (DAME), University of Udine, 33100 Udine, Italy; (V.P.M.); (A.C.)
| | | | | | - Giovanna Lippe
- Department of Medicine (DAME), University of Udine, 33100 Udine, Italy; (V.P.M.); (A.C.)
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Gurung D, Danielson JA, Tasnim A, Zhang JT, Zou Y, Liu JY. Proline Isomerization: From the Chemistry and Biology to Therapeutic Opportunities. BIOLOGY 2023; 12:1008. [PMID: 37508437 PMCID: PMC10376262 DOI: 10.3390/biology12071008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/27/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023]
Abstract
Proline isomerization, the process of interconversion between the cis- and trans-forms of proline, is an important and unique post-translational modification that can affect protein folding and conformations, and ultimately regulate protein functions and biological pathways. Although impactful, the importance and prevalence of proline isomerization as a regulation mechanism in biological systems have not been fully understood or recognized. Aiming to fill gaps and bring new awareness, we attempt to provide a wholistic review on proline isomerization that firstly covers what proline isomerization is and the basic chemistry behind it. In this section, we vividly show that the cause of the unique ability of proline to adopt both cis- and trans-conformations in significant abundance is rooted from the steric hindrance of these two forms being similar, which is different from that in linear residues. We then discuss how proline isomerization was discovered historically followed by an introduction to all three types of proline isomerases and how proline isomerization plays a role in various cellular responses, such as cell cycle regulation, DNA damage repair, T-cell activation, and ion channel gating. We then explore various human diseases that have been linked to the dysregulation of proline isomerization. Finally, we wrap up with the current stage of various inhibitors developed to target proline isomerases as a strategy for therapeutic development.
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Affiliation(s)
- Deepti Gurung
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH 43614, USA
- Department of Cell and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Jacob A Danielson
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Afsara Tasnim
- Department of Bioengineering, University of Toledo College of Engineering, Toledo, OH 43606, USA
| | - Jian-Ting Zhang
- Department of Cell and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Yue Zou
- Department of Cell and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Jing-Yuan Liu
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH 43614, USA
- Department of Cell and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
- Department of Bioengineering, University of Toledo College of Engineering, Toledo, OH 43606, USA
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Kumutima J, Yao XQ, Hamelberg D. Post-translational Modifications of Cyclophilin D Fine-Tune Its Conformational Dynamics and Activity: Implications for Its Mitochondrial Function. J Phys Chem B 2022; 126:10844-10853. [PMID: 36529932 DOI: 10.1021/acs.jpcb.2c06208] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Mitochondria are the powerhouse of a cell, whose disruption due to mitochondrial pore opening can cause cell death, leading to necrosis and many other diseases. The peptidyl-prolyl cis-trans isomerase cyclophilin D (CypD) is a key player in the regulation of the mitochondrial pore. The activity of CypD can be modulated by the post-translational modification (PTM). However, the detailed mechanism of this functional modulation is not well understood. Here, we investigate the catalytic mechanism of unmodified and modified CypD by calculating the reaction free energy profiles and characterizing the function-related conformational dynamics using molecular dynamics simulations and associated analyses. Our results show that unmodified and modified CypD considerably lower the isomerization free energy barrier compared to a free peptide substrate, supporting the catalytic activity of CypD in the simulation systems. The unmodified CypD reduces the free energy difference between the cis and trans states of the peptide substrate, suggesting a stronger binding affinity of CypD toward cis, consistent with experiments. In contrast, phosphorylated CypD further stabilizes trans, leading to a lower catalytic rate in the trans-to-cis direction. The differential catalytic activities of the unmodified and phosphorylated CypD are due to a significant shift of the conformational ensemble upon phosphorylation under different functional states. Interestingly, the local flexibility is both reduced and enhanced at distinct regions by phosphorylation, which is explained by a "seesaw" model of flexibility modulation. The allosteric pathway between the phosphorylation site and a distal site displaying substantial conformational changes upon phosphorylation is also identified, which is influenced by the presence of the substrate or the substrate conformation. Similar conclusions are obtained for the acetylation of CypD using the same peptide substrate and the influence of substrate sequence is also examined. Our work may serve as the basis for the understanding of other PTMs and PTM-initiated allosteric regulations in CypD.
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Zhao J, Liu X, Blayney A, Zhang Y, Gandy L, Mirsky PO, Smith N, Zhang F, Linhardt RJ, Chen J, Baines C, Loh SN, Wang C. Intrinsically Disordered N-terminal Domain (NTD) of p53 Interacts with Mitochondrial PTP Regulator Cyclophilin D. J Mol Biol 2022; 434:167552. [PMID: 35341741 DOI: 10.1016/j.jmb.2022.167552] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 03/11/2022] [Accepted: 03/15/2022] [Indexed: 11/26/2022]
Abstract
Mitochondrial permeability transition pore (mPTP) plays crucial roles in cell death in a variety of diseases, including ischemia/reperfusion injury in heart attack and stroke, neurodegenerative conditions, and cancer. To date, cyclophilin D is the only confirmed component of mPTP. Under stress, p53 can translocate into mitochondria and interact with CypD, triggering necrosis and cell growth arrest. However, the molecular details of p53/CypD interaction are still poorly understood. Previously, several studies reported that p53 interacts with CypD through its DNA-binding domain (DBD). However, using surface plasmon resonance (SPR), we found that both NTD-DBD, NTD and NTD (1-70) bind to CypD at ∼μM KD. In solution NMR, NTD binds CypD with μM affinity and mimics the pattern of FLp53 binding in chemical shift perturbation. In contrast, neither solution NMR nor fluorescence anisotropy detected DBD binding to CypD. Thus, instead of DBD, NTD is the major CypD binding site on p53. NMR titration and MD simulation revealed that NTD binds CypD with broad and dynamic interfaces dominated by electrostatic interactions. NTD 20-70 was further identified as the minimal binding region for CypD interaction, and two NTD fragments, D1 (residues 22-44) and D2 (58-70), can each bind CypD with mM affinity. Our detailed biophysical characterization of the dynamic interface between NTD and CypD provides novel insights on the p53-dependent mPTP opening and drug discovery targeting NTD/CypD interface in diseases.
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Affiliation(s)
- Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY 12180, United States; Present address: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Xinyue Liu
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY 12180, United States; Present address: Department of Cell Biology, Harvard Medical School
| | - Alan Blayney
- Department Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, United States
| | - Yumeng Zhang
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, United States
| | - Lauren Gandy
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY 12180, United States; Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, United States. https://twitter.com/a_science_life
| | | | - Nathan Smith
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY 12180, United States; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, United States
| | - Fuming Zhang
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY 12180, United States; Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, United States
| | - Robert J Linhardt
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY 12180, United States; Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, United States
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, United States
| | - Christopher Baines
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65211, USA
| | - Stewart N Loh
- Department Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, United States
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY 12180, United States; Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, United States; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, United States.
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Yao XQ, Hamelberg D. From Distinct to Differential Conformational Dynamics to Map Allosteric Communication Pathways in Proteins. J Phys Chem B 2022; 126:2612-2620. [PMID: 35319195 DOI: 10.1021/acs.jpcb.2c00199] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Initiation of biological processes involving protein-ligand binding, transient protein-protein interactions, or amino acid modifications alters the conformational dynamics of proteins. Accompanying these biological processes are ensuing coupled atomic level conformational changes within the proteins. These conformational changes collectively connect multiple amino acid residues at distal allosteric, binding, and/or active sites. Local changes due to, for example, binding of a regulatory ligand at an allosteric site initiate the allosteric regulation. The allosteric signal propagates throughout the protein structure, causing changes at distal sites, activating, deactivating, or modifying the function of the protein. Hence, dynamical responses within protein structures to stimuli contain critical information on protein function. In this Perspective, we examine the description of allosteric regulation from protein dynamical responses and associated alternative and emerging computational approaches to map allosteric communication pathways between distal sites in proteins at the atomic level.
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Affiliation(s)
- Xin-Qiu Yao
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302-3965, United States
| | - Donald Hamelberg
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302-3965, United States
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