1
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Chen X, Cao Z, Wang Y. Amyotrophic Lateral Sclerosis-Associated Mutants of SOD1 Perturb mRNA Splicing through Aberrant Interactions with SRSF2. Anal Chem 2024; 96:9713-9720. [PMID: 38795036 DOI: 10.1021/acs.analchem.4c01770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2024]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that results in the degeneration of neurons in the brain and spinal cord. Although a substantial number of studies have been conducted, much remains to be learned about the cellular mechanisms underlying ALS. In this study, we employed an engineered ascorbate peroxidase (APEX)-based proximity biotinylation, together with affinity pull-down of the ensuing biotinylated peptides, to investigate the proximity proteomes of human SOD1 and its two ALS-linked mutants, G85R and G93A. We were able to identify 25 common biotinylated peptides with preferential enrichment in the proximity proteomes of SOD1G85R and SOD1G93A over wild-type SOD1. Our coimmunoprecipitation followed by Western blot analyses revealed that one of these proteins, SRSF2, binds more strongly with the two SOD1 mutants than its wild-type counterpart. We also observed aberrant splicing of mRNAs in cells with ectopic expression of the two SOD1 mutants relative to cells expressing the wild-type protein. In addition, the aberrations in splicing elicited by the SOD1 variants were markedly attenuated upon knockdown of SRSF2. Collectively, we uncovered that ALS-liked SOD1G85R and SOD1G93A mutants interact more strongly with SRSF2, where the aberrant interactions perturbed mRNA splicing. Thus, our work offered novel mechanistic insights into the contributions of the ALS-linked SOD1 mutants to disease etiology.
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Affiliation(s)
- Xingyuan Chen
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92502, United States
| | - Zhongwen Cao
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92502, United States
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92502, United States
- Department of Chemistry, University of California, Riverside, California 92502, United States
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2
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Shrikondawar AN, Chennoju K, Ghosh DK, Ranjan A. Identification and characterization of nuclear localization signals in the circumsporozoite protein of Plasmodium falciparum. FEBS Lett 2024; 598:801-817. [PMID: 38369616 DOI: 10.1002/1873-3468.14829] [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: 11/09/2023] [Revised: 12/30/2023] [Accepted: 01/15/2024] [Indexed: 02/20/2024]
Abstract
Secretory proteins of Plasmodium exhibit differential spatial and functional activity within the host cell nucleus. However, the nuclear localization signals (NLSs) for these proteins remain largely uncharacterized. In this study, we have identified and characterized two NLSs in the circumsporozoite protein of Plasmodium falciparum (Pf-CSP). Both NLSs in the Pf-CSP contain clusters of lysine and arginine residues essential for specific interactions with the conserved tryptophan and asparagine residues of importin-α, facilitating nuclear translocation of Pf-CSP. While the two NLSs of Pf-CSP function independently and are both crucial for nuclear localization, a single NLS of Pf-CSP leads to weak nuclear localization. These findings shed light on the mechanism of nuclear penetrability of secretory proteins of Plasmodium proteins.
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Affiliation(s)
- Akshaykumar Nanaji Shrikondawar
- Computational and Functional Genomics Group, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
- Graduate Studies, Regional Centre for Biotechnology, Faridabad, India
| | - Kiranmai Chennoju
- Computational and Functional Genomics Group, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
- Graduate Studies, Manipal Academy of Higher Education, Manipal, India
| | | | - Akash Ranjan
- Computational and Functional Genomics Group, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
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3
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Chen L, Zhang S, Liu S, Gao S. Amyotrophic Lateral Sclerosis Mechanism: Insights from the Caenorhabditis elegans Models. Cells 2024; 13:99. [PMID: 38201303 PMCID: PMC10778397 DOI: 10.3390/cells13010099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/28/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a debilitating neurodegenerative condition characterized by the progressive degeneration of motor neurons. Despite extensive research in various model animals, the cellular signal mechanisms of ALS remain elusive, impeding the development of efficacious treatments. Among these models, a well-characterized and diminutive organism, Caenorhabditis elegans (C. elegans), has emerged as a potent tool for investigating the molecular and cellular dimensions of ALS pathogenesis. This review summarizes the contributions of C. elegans models to our comprehension of ALS, emphasizing pivotal findings pertaining to genetics, protein aggregation, cellular pathways, and potential therapeutic strategies. We analyze both the merits and constraints of the C. elegans system in the realm of ALS research and point towards future investigations that could bridge the chasm between C. elegans foundational discoveries and clinical applications.
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Affiliation(s)
| | | | | | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; (L.C.); (S.Z.); (S.L.)
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4
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Dash R, Munni YA, Mitra S, Choi HJ, Jahan SI, Chowdhury A, Jang TJ, Moon IS. Dynamic insights into the effects of nonsynonymous polymorphisms (nsSNPs) on loss of TREM2 function. Sci Rep 2022; 12:9378. [PMID: 35672339 PMCID: PMC9174165 DOI: 10.1038/s41598-022-13120-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 05/16/2022] [Indexed: 11/09/2022] Open
Abstract
Single nucleotide variations in Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) are associated with many neurodegenerative diseases, including Nasu-Hakola disease (NHD), frontotemporal dementia (FTD), and late-onset Alzheimer's disease because they disrupt ligand binding to the extracellular domain of TREM2. However, the effects of nonsynonymous single nucleotide polymorphisms (nsSNPs) in TREM2 on disease progression remain unknown. In this study, we identified several high-risk nsSNPs in the TREM2 gene using various deleterious SNP predicting algorithms and analyzed their destabilizing effects on the ligand recognizing region of the TREM2 immunoglobulin (Ig) domain by molecular dynamics (MD) simulation. Cumulative prediction by all tools employed suggested the three most deleterious nsSNPs involved in loss of TREM2 function are rs549402254 (W50S), rs749358844 (R52C), and rs1409131974 (D104G). MD simulation showed that these three variants cause substantial structural alterations and conformational remodeling of the apical loops of the TREM2 Ig domain, which is responsible for ligand recognition. Detailed analysis revealed that these variants substantially increased distances between apical loops and induced conformation remodeling by changing inter-loop nonbonded contacts. Moreover, all nsSNPs changed the electrostatic potentials near the putative ligand-interacting region (PLIR), which suggested they might reduce specificity or loss of binding affinity for TREM2 ligands. Overall, this study identifies three potential high-risk nsSNPs in the TREM2 gene. We propose further studies on the molecular mechanisms responsible for loss of TREM2 function and the associations between TREM2 nsSNPs and neurodegenerative diseases.
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Affiliation(s)
- Raju Dash
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Yeasmin Akter Munni
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Sarmistha Mitra
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Ho Jin Choi
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Sultana Israt Jahan
- Department of Biotechnology and Genetic Engineering, Noakhali Science and Technology University, Noakhali, 3814, Bangladesh
| | - Apusi Chowdhury
- Department of Pharmaceutical Science, North-South University, Dhaka, 1229, Bangladesh
| | - Tae Jung Jang
- Department of Pathology, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Il Soo Moon
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea.
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5
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Abstract
Selective degradation of protein aggregates by macroautophagy/autophagy is an essential homeostatic process of safeguarding cells from the effects of proteotoxicity. Among the ubiquitin-like proteins, NEDD8 conjugation to misfolded proteins is prominent in stress-induced protein aggregates, albeit the function of neddylation in autophagy is unclear. Here, we report that polyneddylation functions as a post-translational modification for autophagic degradation of proteotoxic-stress induced protein aggregates. We also show that HYPK functions as an autophagy receptor in the polyneddylation-dependent aggrephagy. The scaffolding function of HYPK is facilitated by its C-terminal ubiquitin-associated domain and N-terminal tyrosine-type LC3-interacting region which bind to NEDD8 and LC3 respectively. Both NEDD8 and HYPK are positive modulators of basal and proteotoxicity-induced autophagy, leading to protection of cells from protein aggregates, such as aggregates of mutant HTT exon 1. Thus, we propose an indispensable and additive role of neddylation and HYPK in clearance of protein aggregates by autophagy, resulting in cytoprotective effect during proteotoxic stress.Abbreviations: ATG5, autophagy related 5; ATG12, autophagy related 12; ATG14, autophagy related 14; BECN1, beclin 1; CBL, casitas B-lineage lymphoma; CBLB, Cbl proto-oncogene B; GABARAP, GABA type A receptor-associated protein; GABARAPL1, GABA type A receptor associated protein like 1; GABARAPL2, GABA type A receptor associated protein like 2; GFP, green fluorescent protein; HTT, huntingtin; HTT97Q exon 1, huntingtin 97-glutamine exon 1; HUWE1, HECT, UBA and WWE domain containing E3 ubiquitin protein ligase 1; HYPK, huntingtin interacting protein K; IgG, immunoglobulin G; IMR-32, Institute for Medical Research-32; KD, knockdown; Kd, dissociation constant; LAMP1, lysosomal associated membrane protein 1; LIR, LC3 interacting region; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MAP1LC3A/LC3A, microtubule associated protein 1 light chain 3 alpha; MAP1LC3B/LC3B, microtubule associated protein 1 light chain 3 beta; MARK1, microtubule affinity regulating kinase 1; MARK2, microtubule affinity regulating kinase 2; MARK3, microtubule affinity regulating kinase 3; MARK4, microtubule affinity regulating kinase 4; MCF7, Michigan Cancer Foundation-7; MTOR, mechanistic target of rapamycin kinase; NAE1, NEDD8 activating enzyme E1 subunit 1; NBR1, NBR1 autophagy cargo receptor; NEDD8, NEDD8 ubiquitin like modifier; Ni-NTA, nickel-nitrilotriacetic acid; NUB1, negative regulator of ubiquitin like proteins 1; PIK3C3, phosphatidylinositol 3-kinase catalytic subunit type 3; PolyQ, poly-glutamine; PSMD8, proteasome 26S subunit, non-ATPase 8; RAD23A, RAD23 homolog A, nucleotide excision repair protein; RAD23B, RAD23 homolog B, nucleotide excision repair protein; RFP, red fluorescent protein; RPS27A, ribosomal protein S27a; RSC1A1, regulator of solute carriers 1; SNCA, synuclein alpha; SIK1, salt inducible kinase 1; siRNA, small interfering ribonucleic acid; SOD1, superoxide dismutase 1; SPR, surface plasmon resonance; SQSTM1, sequestosome 1; SUMO1, small ubiquitin like modifier 1; TAX1BP1, Tax1 binding protein 1; TDRD3, tudor domain containing 3; TNRC6C, trinucleotide repeat containing adaptor 6C; TOLLIP, toll interacting protein; TUBA, tubulin alpha; TUBB, tubulin beta class I; UBA, ubiquitin-associated; UBA1, ubiquitin like modifier activating enzyme 1; UBA5, ubiquitin like modifier activating enzyme 5; UBAC1, UBA domain containing 1; UBAC2, UBA domain containing 2; UBAP1, ubiquitin associated protein 1; UBAP2, ubiquitin associated protein 2; UBASH3B, ubiquitin associated and SH3 domain containing B; UBD/FAT10, ubiquitin D; UBE2K, ubiquitin conjugating enzyme E2 K; UBLs, ubiquitin-like proteins; UBL7, ubiquitin like 7; UBQLN1, ubiquilin 1; UBQLN2, ubiquilin 2; UBQLN3, ubiquilin 3; UBQLN4, ubiquilin 4; UBXN1, UBX domain protein 1; ULK1, unc-51 like autophagy activating kinase 1; URM1, ubiquitin related modifier 1; USP5, ubiquitin specific peptidase 5; USP13, ubiquitin specific peptidase 13; VPS13D, vacuolar protein sorting 13 homolog D.
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Affiliation(s)
- Debasish Kumar Ghosh
- Computational and Functional Genomics Group Centre for Dna Fingerprinting and Diagnostics Uppal Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | - Akash Ranjan
- Computational and Functional Genomics Group Centre for Dna Fingerprinting and Diagnostics Uppal Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
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6
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The intrinsic amyloidogenic propensity of cofilin-1 is aggravated by Cys-80 oxidation: A possible link with neurodegenerative diseases. Biochem Biophys Res Commun 2021; 569:187-192. [PMID: 34256187 DOI: 10.1016/j.bbrc.2021.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/05/2021] [Indexed: 11/23/2022]
Abstract
Cofilin-1, an actin dynamizing protein, forms actin-cofilin rods, which is one of the major events that exacerbates the pathophysiology of amyloidogenic diseases. Cysteine oxidation in cofilin-1 under oxidative stress plays a crucial role in the formation of these rods. Others and we have reported that cofilin-1 possesses a self-oligomerization property in vitro and in vivo under physiological conditions. However, it remains elusive if cofilin-1 itself forms amyloid-like structures. We, therefore, hypothesized that cofilin-1 might form amyloid-like assemblies, with a potential to intensify the pathophysiology of amyloid-linked diseases. We used various in silico and in vitro techniques and examined the amyloid-forming propensity of cofilin-1. The study confirms that cofilin-1 possesses an intrinsic tendency of aggregation and forms amyloid-like structures in vitro. Further, we studied the effect of cysteine oxidation on the stability and structural features of cofilin-1. Our data show that oxidation at Cys-80 renders cofilin-1 unstable, leading to a partial loss of protein structure. The results substantiate our hypothesis and establish a strong possibility that cofilin-1 aggregation might play a role in cofilin-mediated pathology and the progression of several amyloid-linked diseases.
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7
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Azizian H, Forooghian S, Amanlou A, Pérez-Sánchez H, Amanlou M. Phenothiazine as novel human superoxide dismutase modulators: discovery, optimization, and biological evaluation. J Biomol Struct Dyn 2021; 40:7070-7083. [PMID: 33663349 DOI: 10.1080/07391102.2021.1893819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Superoxide dismutases (SODs) are regarded as important antioxidants for protecting cells against damage arising from oxidative stress. Much research is focused on finding new chemicals with an ability to boost human SOD activity. In the research described herein a structure-based approach was used to identify new human Cu-Zn superoxide dismutase (SOD1) modulators based on previously reported plasmodium falciparum iron SOD inhibitors using induced fit docking and molecular dynamic (MD) protocols. The compound with the highest docking binding energy was selected for further structure simplification followed by structural similarity and MD in order to find a new activator/inhibitor scaffold of the SOD1 enzyme. According to the docking survey of the mentioned series, 1,4-bis(3-(1,4,8-trichloro-10Hphenothiazin-10-yl) propyl) piperazine (DS88) was the top scoring compound interacting with the SOD1 active site channel. Following structure simplification and similarity search, the most promising scaffold which is closely related to the phenothiazine antipsychotic class, was identified. Compared with the normal blood SOD1 activity, the percent of O2 production increased with trifluoperazine, while it decreased with the chlorpromazine. The molecular dynamic investigation shows that trifluoperazine exerts its SOD1 activating effect by stabilizing electrostatic loop while chlorpromazine employs SOD1 inhibition activity through repositioning of the electrostatic loop and increasing its distance from the catalytic metal site which diminished substrate specificity and catalytic activity of the SOD1 enzyme. The results identified the preferred region, orientation, and types of interaction for each activator or inhibitor compound.
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Affiliation(s)
- Homa Azizian
- Department of Medicinal Chemistry, School of Pharmacy, Iran University of Medical Sciences, Tehran Iran
| | - Simin Forooghian
- Faculty of Basic Science, Department of Biology, Tehran Payame Noor University, Tehran, Iran
| | - Arash Amanlou
- Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Horacio Pérez-Sánchez
- Structural Bioinformatics and High-Performance Computing Research Group (BIO-HPC), Computer Engineering Department, Universidad Católica de Murcia (UCAM), Murcia, Spain
| | - Massoud Amanlou
- Faculty of Pharmacy, Department of Medicinal Chemistry, Tehran University of Medical Sciences, Tehran, Iran.,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
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8
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Kumar A, Ghosh DK, Ranjan A. Differential Stabilities of Mefloquine-Bound Human and Plasmodium falciparum Acyl-CoA-Binding Proteins. ACS OMEGA 2021; 6:1883-1893. [PMID: 33521428 PMCID: PMC7841788 DOI: 10.1021/acsomega.0c04582] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 12/01/2020] [Indexed: 05/03/2023]
Abstract
Toxic effects of pharmacological drugs restrict their robust application against human diseases. Although used as a drug in the combinatorial therapy to treat malaria, the use of mefloquine is not highly recommended because of its adverse effects in humans. Mefloquine inhibits the binding of acyl-CoAs to acyl-CoA-binding proteins of Plasmodium falciparum (PfACBPs) and human (hACBP). In this study, we have used molecular dynamics simulation and other computational approaches to investigate the differences of stabilities of mefloquine-PfACBP749 and mefloquine-hACBP complexes. The stability of mefloquine in the binding cavity of PfACBP749 is less than its stability in the binding pocket of hACBP. Although the essential tyrosine residues (tyrosine-30 and tyrosine-33 of PfACBP749 and tyrosine-29 and tyrosine-32 of hACBP) mediate the initial binding of mefloquine to the proteins by π-stacking interactions, additional temporally longer interactions between mefloquine and aspartate-22 and methionine-25 of hACBP result in stronger binding of mefloquine to hACBP. The higher fluctuation of mefloquine-binding residues of PfACBP749 contributes to the instability of mefloquine in the binding cavity of the protein. On the contrary, in the mefloquine-bound state, the stability of hACBP protein is less than the stability of PfACBP749. The helix-to-coil transition of the N-terminal hydrophobic region of hACBP has a destabilizing effect upon the protein's structure. This causes the induction of aggregation properties in the hACBP in the mefloquine-bound state. Taken together, we describe the mechanistic features that affect the differential dynamic stabilities of mefloquine-bound PfACBP749 and hACBP proteins.
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Affiliation(s)
- Abhishek Kumar
- Computational
and Functional Genomics Group, Centre for
DNA Fingerprinting and Diagnostics, Uppal, Hyderabad, Telangana 500039, India
- Graduate
Studies, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Debasish Kumar Ghosh
- Computational
and Functional Genomics Group, Centre for
DNA Fingerprinting and Diagnostics, Uppal, Hyderabad, Telangana 500039, India
| | - Akash Ranjan
- Computational
and Functional Genomics Group, Centre for
DNA Fingerprinting and Diagnostics, Uppal, Hyderabad, Telangana 500039, India
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9
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Caldwell KA, Willicott CW, Caldwell GA. Modeling neurodegeneration in Caenorhabditis elegans. Dis Model Mech 2020; 13:13/10/dmm046110. [PMID: 33106318 PMCID: PMC7648605 DOI: 10.1242/dmm.046110] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The global burden of neurodegenerative diseases underscores the urgent need for innovative strategies to define new drug targets and disease-modifying factors. The nematode Caenorhabditis elegans has served as the experimental subject for multiple transformative discoveries that have redefined our understanding of biology for ∼60 years. More recently, the considerable attributes of C. elegans have been applied to neurodegenerative diseases, including amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease and Huntington's disease. Transgenic nematodes with genes encoding normal and disease variants of proteins at the single- or multi-copy level under neuronal-specific promoters limits expression to select neuronal subtypes. The anatomical transparency of C. elegans affords the use of co-expressed fluorescent proteins to follow the progression of neurodegeneration as the animals age. Significantly, a completely defined connectome facilitates detailed understanding of the impact of neurodegeneration on organismal health and offers a unique capacity to accurately link cell death with behavioral dysfunction or phenotypic variation in vivo. Moreover, chemical treatments, as well as forward and reverse genetic screening, hasten the identification of modifiers that alter neurodegeneration. When combined, these chemical-genetic analyses establish critical threshold states to enhance or reduce cellular stress for dissecting associated pathways. Furthermore, C. elegans can rapidly reveal whether lifespan or healthspan factor into neurodegenerative processes. Here, we outline the methodologies employed to investigate neurodegeneration in C. elegans and highlight numerous studies that exemplify its utility as a pre-clinical intermediary to expedite and inform mammalian translational research. Summary: While unsurpassed as an experimental system for fundamental biology, Caenorhabditis elegans remains undervalued for its translational potential. Here, we highlight significant outcomes from, and resources available for, C. elegans-based research into neurodegenerative disorders.
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Affiliation(s)
- Kim A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA .,Departments of Neurobiology, Neurology, Center for Neurodegeneration and Experimental Therapeutics, and Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Corey W Willicott
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Guy A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA.,Departments of Neurobiology, Neurology, Center for Neurodegeneration and Experimental Therapeutics, and Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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10
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Ghosh DK, Ranjan A. The metastable states of proteins. Protein Sci 2020; 29:1559-1568. [PMID: 32223005 PMCID: PMC7314396 DOI: 10.1002/pro.3859] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 12/26/2022]
Abstract
The intriguing process of protein folding comprises discrete steps that stabilize the protein molecules in different conformations. The metastable state of protein is represented by specific conformational characteristics, which place the protein in a local free energy minimum state of the energy landscape. The native-to-metastable structural transitions are governed by transient or long-lived thermodynamic and kinetic fluctuations of the intrinsic interactions of the protein molecules. Depiction of the structural and functional properties of metastable proteins is not only required to understand the complexity of folding patterns but also to comprehend the mechanisms of anomalous aggregation of different proteins. In this article, we review the properties of metastable proteins in context of their stability and capability of undergoing atypical aggregation in physiological conditions.
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Affiliation(s)
- Debasish Kumar Ghosh
- Computational and Functional Genomics Group, Centre for DNA Fingerprinting and DiagnosticsUppal, HyderabadTelanganaIndia
| | - Akash Ranjan
- Computational and Functional Genomics Group, Centre for DNA Fingerprinting and DiagnosticsUppal, HyderabadTelanganaIndia
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11
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Dash R, Choi HJ, Moon IS. Mechanistic insights into the deleterious roles of Nasu-Hakola disease associated TREM2 variants. Sci Rep 2020; 10:3663. [PMID: 32107424 PMCID: PMC7046722 DOI: 10.1038/s41598-020-60561-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 02/13/2020] [Indexed: 02/06/2023] Open
Abstract
Recently, the critical roles played by genetic variants of TREM2 (Triggering Receptor Expressed on Myeloid cells 2) in Alzheimer's disease have been aggressively highlighted. However, few studies have focused on the deleterious roles of Nasu-Hakola disease (NHD) associated TREM2 variants. In order to get insights into the contributions made by these variants to neurodegeneration, we investigated the influences of four NHD associated TREM2 mutations (Y38C, W50C, T66M, and V126G) on loss-of-function, and followed this with in silico prediction and conventional molecular dynamics simulation. NHD mutations were predicted to be highly deleterious by eight different in silico bioinformatics tools and found to induce conformational changes by molecular dynamics simulation. As compared with the wild-type, the four variants produced substantial differences in the collective motions of loop regions, which not only promoted structural remodeling in the CDR2 (complementarity-determining region 2) loop but also in the CDR1 loop, by changing inter- and intra-loop hydrogen bonding networks. In addition, structural studies in a free energy landscape analysis showed that Y38, T66, and V126 are crucial for maintaining the structural features of CDR1 and CDR2 loops, and that mutations in these positions produced steric clashes and loss of ligand binding. These results showed the presence of mutations in the TREM2 ectodomain induced flexibility and caused structural alterations. Dynamical scenarios, as provided by the present study, may be critical to our understanding of the roles of these TREM2 mutations in neurodegenerative diseases.
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Affiliation(s)
- Raju Dash
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Ho Jin Choi
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Il Soo Moon
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea.
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12
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Kaku H, Ludlow AV, Gutknecht MF, Rothstein TL. FAIM Opposes Aggregation of Mutant SOD1 That Typifies Some Forms of Familial Amyotrophic Lateral Sclerosis. Front Neurosci 2020; 14:110. [PMID: 32153351 PMCID: PMC7047752 DOI: 10.3389/fnins.2020.00110] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/28/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative illness that is unremittingly fatal and for which no effective treatment exists. All forms of ALS are characterized by protein aggregation. In familial forms of ALS, specific and heritable aggregation-prone proteins have been identified, such as mutant superoxide dismutase (SOD1). It has been suggested that a factor capable of preventing mutant SOD1 protein aggregation and/or disassembling mutant SOD1 protein aggregates would ameliorate SOD1-associated forms of familial ALS. Here we identify Fas Apoptosis Inhibitory Molecule (FAIM), a highly evolutionarily conserved 20 kDa protein, as an agent with this activity. We show FAIM counteracts intracellular accumulation of mutant SOD1 protein aggregates, which is increased in the absence of FAIM, as determined by pulse-shape analysis and filter trap assays. In a cell-free system, FAIM inhibits aggregation of mutant SOD1, and further disassembles and solubilizes established mutant SOD1 protein aggregates, as determined by thioflavin T (ThT), filter trap, and sedimentation assays. In sum, we report here a previously unknown activity of FAIM that opposes ALS disease-related protein aggregation and promotes proteostasis of an aggregation-prone ALS protein.
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Affiliation(s)
- Hiroaki Kaku
- Center for Immunobiology, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, United States.,Department of Biomedical Sciences, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, United States
| | - Alexander V Ludlow
- Center for Immunobiology, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, United States
| | - Michael F Gutknecht
- Center for Immunobiology, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, United States
| | - Thomas L Rothstein
- Center for Immunobiology, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, United States.,Department of Biomedical Sciences, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, United States
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Ghosh DK, Kumar A, Ranjan A. T54R mutation destabilizes the dimer of superoxide dismutase 1T54R by inducing steric clashes at the dimer interface. RSC Adv 2020; 10:10776-10788. [PMID: 35492906 PMCID: PMC9050410 DOI: 10.1039/c9ra09870d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/28/2020] [Indexed: 11/29/2022] Open
Abstract
Mutations cause abnormalities in protein structure, function and oligomerization. Different mutations in the superoxide dismutase 1 (SOD1) protein cause its misfolding, loss of dimerization and aggravate its aggregation in the amyotrophic lateral sclerosis disease. In this study, we report the mechanistic details of how a threonine-to-arginine mutation at the 54th position (T54R) of SOD1 results in destabilization of the dimer interface of SOD1T54R. Using computational and experimental methods, we show that the T54R mutation increases fluctuation of the mutation-harboring loop (R54-loop) of SOD1T54R. Fluctuation of this loop causes steric clashes that involve arginine-54 (R54) and other residues of SOD1T54R, resulting in loss of inter-subunit contacts at the dimer interface. Since the T54 residue-containing loop is necessary for the dimerization of wild-type SOD1, fluctuation of the R54-loop, steric clashes involving R54 and loss of inter-subunit contacts give rise to the loss of SOD1T54R dimer stability. This correlates to energetically unfavorable tethering of the monomers of SOD1T54R. The outcome is gradual splitting of SOD1T54R dimers into monomers, thereby exposing the previously buried hydrophobic interface residues to the aqueous environment. This event finally leads to aggregation of SOD1T54R. T54R mutation has no effect in altering the relative positions of copper and zinc ion binding residues of SOD1T54R. The native SOD1 structure is stable, and there is no destabilizing effect at its dimer interface. Overall, our study reveals the intricate mechanism of T54R mutation-associated destabilization of the dimer of the SOD1T54R protein. T54R mutation destabilizes the dimer of SOD1T54R.![]()
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Affiliation(s)
- Debasish Kumar Ghosh
- Computational and Functional Genomics Group
- Centre for DNA Fingerprinting and Diagnostics
- Hyderabad 500039
- India
| | - Abhishek Kumar
- Computational and Functional Genomics Group
- Centre for DNA Fingerprinting and Diagnostics
- Hyderabad 500039
- India
- Graduate Studies
| | - Akash Ranjan
- Computational and Functional Genomics Group
- Centre for DNA Fingerprinting and Diagnostics
- Hyderabad 500039
- India
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Kumar A, Ghosh DK, Ali J, Ranjan A. Characterization of Lipid Binding Properties of Plasmodium falciparum Acyl-Coenzyme A Binding Proteins and Their Competitive Inhibition by Mefloquine. ACS Chem Biol 2019; 14:901-915. [PMID: 30986346 DOI: 10.1021/acschembio.9b00003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Malaria remains a worldwide concern in terms of morbidity and mortality. Limited understanding of the Plasmodium proteome makes it challenging to control malaria. Understanding of the expression and functions of different Plasmodium proteins will help in knowing this organism's virulence properties, besides facilitating the drug development process. In this study, we characterize the lipid binding and biophysical properties of the putative Plasmodium falciparum acyl-CoA binding proteins (PfACBPs), which may have intriguing functions in different stages of P. falciparum life cycle. While the PfACBPs can bind to long-chain fatty acyl-CoAs with high affinity, their affinity for short-chain fatty acyl-CoAs is weak. Base-stacking, electrostatic, and hydrophobic interactions between the aromatic rings, charged groups or residues, and hydrophobic chains or residues are responsible for acyl-CoA binding to PfACBPs. PfACBPs can also bind to phospholipids. PfACBPs cannot bind to the fatty acids and unphosphorylated fatty acid esters. PfACBPs are globular-helical proteins that contain a conserved acyl-CoA binding region. They exist in folded or unfolded conformations without attaining any intermediate state. In a systematic high-throughput in silico screening, mefloquine is identified as a potential ligand of PfACBPs. Binding affinities of mefloquine are much higher than those of fatty acyl-CoAs for all PfACBPs. Mefloquine binds to the acyl-CoA binding pocket of PfACBPs, thereby engaging many of the critical residues. Thus, mefloquine acts as a competitive inhibitor against fatty acyl-CoA binding to PfACBPs, leading to the prevention of P. falciparum growth and proliferation. Taken together, our study characterizes the functions of annotated PfACBPs and highlights the mechanistic details of their inactivation by mefloquine.
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Affiliation(s)
- Abhishek Kumar
- Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Uppal, Hyderabad, Telangana 500039, India
- Graduate studies, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Debasish Kumar Ghosh
- Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Uppal, Hyderabad, Telangana 500039, India
- Graduate studies, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Jamshaid Ali
- Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Uppal, Hyderabad, Telangana 500039, India
- Graduate studies, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
- Rajiv Gandhi Centre for Biotechnology Thiruvananthapuram, Kerala 695014, India
| | - Akash Ranjan
- Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Uppal, Hyderabad, Telangana 500039, India
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