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Itagi P, Kante A, Lagunes L, Deeds EJ. Understanding the separation of timescales in bacterial proteasome core particle assembly. Biophys J 2022; 121:3975-3986. [PMID: 36016496 PMCID: PMC9674962 DOI: 10.1016/j.bpj.2022.08.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 08/10/2022] [Accepted: 08/19/2022] [Indexed: 11/29/2022] Open
Abstract
The 20S proteasome core particle (CP) is a molecular machine that is a key component of cellular protein degradation pathways. Like other molecular machines, it is not synthesized in an active form but rather as a set of subunits that assemble into a functional complex. The CP is conserved across all domains of life and is composed of 28 subunits, 14 α and 14 β, arranged in four stacked seven-member rings (α7β7β7α7). While details of CP assembly vary across species, the final step in the assembly process is universally conserved: two half proteasomes (HPs; α7β7) dimerize to form the CP. In the bacterium Rhodococcus erythropolis, experiments have shown that the formation of the HP is completed within minutes, while the dimerization process takes hours. The N-terminal propeptide of the β subunit, which is autocatalytically cleaved off after CP formation, plays a key role in regulating this separation of timescales. However, the detailed molecular mechanism of how the propeptide achieves this regulation is unclear. In this work, we used molecular dynamics simulations to characterize HP conformations and found that the HP exists in two states: one where the propeptide interacts with key residues in the HP dimerization interface and likely blocks dimerization, and one where this interface is free. Furthermore, we found that a propeptide mutant that dimerizes extremely slowly is essentially always in the nondimerizable state, while the wild-type rapidly transitions between the two. Based on these simulations, we designed a propeptide mutant that favored the dimerizable state in molecular dynamics simulations. In vitro assembly experiments confirmed that this mutant dimerizes significantly faster than wild-type. Our work thus provides unprecedented insight into how this critical step in CP assembly is regulated, with implications both for efforts to inhibit proteasome assembly and for the evolution of hierarchical assembly pathways.
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Affiliation(s)
- Pushpa Itagi
- Center for Computational Biology, University of Kansas, Lawrence, Kansas; Institute for Quantitative and Computational Biosciences, UCLA, Los Angeles, California
| | - Anupama Kante
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas; Department of Integrative Biology and Physiology, UCLA, Los Angeles, California
| | - Leonila Lagunes
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, California
| | - Eric J Deeds
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, California; Institute for Quantitative and Computational Biosciences, UCLA, Los Angeles, California.
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Jiang HW, Czajkowsky DM, Wang T, Wang XD, Wang JB, Zhang HN, Liu CX, Wu FL, He X, Xu ZW, Chen H, Guo SJ, Li Y, Bi LJ, Deng JY, Xie J, Pei JF, Zhang XE, Tao SC. Identification of Serine 119 as an Effective Inhibitor Binding Site of M. tuberculosis Ubiquitin-like Protein Ligase PafA Using Purified Proteins and M. smegmatis. EBioMedicine 2018; 30:225-236. [PMID: 29622495 PMCID: PMC5952411 DOI: 10.1016/j.ebiom.2018.03.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 03/21/2018] [Accepted: 03/21/2018] [Indexed: 12/26/2022] Open
Abstract
Owing to the spread of multidrug resistance (MDR) and extensive drug resistance (XDR), there is a pressing need to identify potential targets for the development of more-effective anti-M. tuberculosis (Mtb) drugs. PafA, as the sole Prokaryotic Ubiquitin-like Protein ligase in the Pup-proteasome System (PPS) of Mtb, is an attractive drug target. Here, we show that the activity of purified Mtb PafA is significantly inhibited upon the association of AEBSF (4-(2-aminoethyl) benzenesulfonyl fluoride) to PafA residue Serine 119 (S119). Mutation of S119 to amino acids that resemble AEBSF has similar inhibitory effects on the activity of purified Mtb PafA. Structural analysis reveals that although S119 is distant from the PafA catalytic site, it is located at a critical position in the groove where PafA binds the C-terminal region of Pup. Phenotypic studies demonstrate that S119 plays critical roles in the function of Mtb PafA when tested in M. smegmatis. Our study suggests that targeting S119 is a promising direction for developing an inhibitor of M. tuberculosis PafA. The pupylation activity of purified M. tuberculosis PafA is almost completely inhibited upon the association of AEBSF. The AEBSF binding site, Ser 119 plays critical roles in both the pupylation and depupylation activity of purified M. tuberculosis PafA. Disruption of purified M. tuberculosis PafA Ser 119 causes a dramatic reduction in Pup binding.
Drug-resistant tuberculosis is a major challenge worldwide, there is an urgent need to identify potential drug targets for developing more effective anti-tubercular drugs. M. tuberculosis ubiquitin-like protein ligase PafA is an attractive drug target, however, effective PafA inhibitors have not yet been identified. Here, we show that interruption of a single amino acid, S119, causes dramatic loss of PafA activity. S119 could thus serve as a promising precise target for developing M. tuberculosis PafA inhibitors.
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Affiliation(s)
- He-Wei Jiang
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Daniel M Czajkowsky
- School of Biomedical Engineering, Bio-ID Center, Shanghai Jiao Tong University, Shanghai 200240, China; School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tao Wang
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China; SZCDC-SUSTech Joint Key Laboratory for Tropical Diseases, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Xu-De Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jia-Bin Wang
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hai-Nan Zhang
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Cheng-Xi Liu
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Fan-Lin Wu
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiang He
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhao-Wei Xu
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hong Chen
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shu-Juan Guo
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yang Li
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Li-Jun Bi
- National Key Laboratory of Biomacromolecules, Key Laboratory of Non-Coding RNA and Key Laboratory of Protein and Peptide Pharmaceuticals, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; TB Healthcare Biotechnology Co., Ltd., Foshan, Guangdong 528000, China; School of Stomatology and Medicine, Foshan University, Foshan 528000, Guangdong Province, China
| | - Jiao-Yu Deng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jin Xie
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Jian-Feng Pei
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Xian-En Zhang
- National Key Laboratory of Biomacromolecules, Key Laboratory of Non-Coding RNA and Key Laboratory of Protein and Peptide Pharmaceuticals, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Sheng-Ce Tao
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China; School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University, Shanghai 200240, China.
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Zheng Y, Jiang X, Gao F, Song J, Sun J, Wang L, Sun X, Lu Z, Zhang H. Identification of plant-derived natural products as potential inhibitors of the Mycobacterium tuberculosis proteasome. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 14:400. [PMID: 25315519 PMCID: PMC4203866 DOI: 10.1186/1472-6882-14-400] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 10/07/2014] [Indexed: 01/22/2023]
Abstract
Background The Mycobacterium tuberculosis (Mtb) proteasome has been established as a viable target for the development of anti-tuberculosis agents. In this study, the inhibitory activities of 100 plant-derived natural products on the Mtb proteasome were analyzed to identify novel potential inhibitors. Methods The fluorescent substrate Suc-Leu-Leu-Val-Tyr-AMC can be hydrolyzed by the proteasome to release free AMC, the fluorescence of which is proportional to the proteasome activity. The inhibitory activities of 100 natural products (each at a final concentration of 200 μM) were detected by this method using MG132 as a positive control. Results Twelve of these natural products (10 of which were flavonoids) inhibited the activity of the Mtb proteasome by more than 65%. Comparison of the structural differences between the flavonoids with good inhibitory activity and those without inhibitory activity revealed that the hydroxyl at the flavonoid C ring C-3 or the hydroxyl/methoxyl at the flavonoid A ring C-6 were critical for the inhibition of proteasomal activity. Conclusions These data indicate that flavonoids represent a basis for rational structural design in the process of novel anti-tuberculosis drug discovery.
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Jayachandran R, BoseDasgupta S, Pieters J. Surviving the macrophage: tools and tricks employed by Mycobacterium tuberculosis. Curr Top Microbiol Immunol 2014; 374:189-209. [PMID: 23154833 DOI: 10.1007/82_2012_273] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Mycobacterium tuberculosis has evolved to withstand one of the most inhospitable cells within the human body, namely the macrophage, a cell that is normally geared toward the destruction of any invading microbe. How M. tuberculosis achieves this is still incompletely understood; however, a number of mechanisms are now known that provide advantages to M. tuberculosis for its survival and proliferation inside the macrophage. While some of these mechanisms are mediated by factors released by M. tuberculosis, others rely on host components that are being hijacked to benefit survival of M. tuberculosis within the macrophage as well to avoid the generation of an effective immune response. Here, we describe several of these mechanisms, also pointing out the potential usage of this knowledge toward the development of novel strategies to treat tuberculosis. Furthermore, we attempt to put the 'macrophage niche' into context with other intracellular pathogens and discuss some of the generalities as well as specializations that M. tuberculosis employs to survive.
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Affiliation(s)
- Rajesh Jayachandran
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056, Basel, Switzerland
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Jayachandran R, Scherr N, Pieters J. Elimination of intracellularly residing Mycobacterium tuberculosis through targeting of host and bacterial signaling mechanisms. Expert Rev Anti Infect Ther 2013; 10:1007-22. [PMID: 23106276 DOI: 10.1586/eri.12.95] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
With more than 2 billion latently infected people, TB continues to represent a serious threat to human health. According to the WHO, 1.1 million people died from TB in 2010, which is equal to approximately 3000 deaths per day. The causative agent of the disease, Mycobacterium tuberculosis, is a highly successful pathogen having evolved remarkable strategies to persist within the host. Although normally, upon phagocytosis by macrophages, bacteria are readily eliminated by lysosomes, pathogenic mycobacteria actively prevent destruction within macrophages. The strategies that pathogenic mycobacteria apply range from releasing virulence factors to manipulating host molecules resulting in the modulation of host signal transduction pathways in order to sustain their viability within the infected host. Here, we analyze the current status of how a better understanding of both the bacterial and host factors involved in virulence can be used to develop drugs that may be helpful to curb the TB epidemic.
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Affiliation(s)
- Rajesh Jayachandran
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
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