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Mainali N, Balasubramaniam M, Johnson J, Ayyadevara S, Shmookler Reis RJ. Leave-one-out-analysis (LOOA): web-based tool to predict influential proteins and interactions in aggregate-crosslinking proteomic data. Bioinformation 2024; 20:4-10. [PMID: 38352912 PMCID: PMC10859942 DOI: 10.6026/973206300200004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/16/2024] Open
Abstract
Many age-progressive diseases are accompanied by (and likely caused by) the presence of protein aggregation in affected tissues. Protein aggregates are conjoined by complex protein-protein interactions, which remain poorly understood. Knowledge of the proteins that comprise aggregates, and their adherent interfaces, can be useful to identify therapeutic targets to treat or prevent pathology, and to discover small molecules for disease interventions. We present web-based software to evaluate and rank influential proteins and protein-protein interactions based on graph modelling of the cross linked aggregate interactome. We have used two network-graph-based techniques: Leave-One-Vertex-Out (LOVO) and Leave-One-Edge-Out (LOEO), each followed by dimension reduction and calculation of influential vertices and edges using Principal Components Analysis (PCA) implemented as an R program. This method enables researchers to quickly and accurately determine influential proteins and protein-protein interactions present in their aggregate interactome data.
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Affiliation(s)
- Nirjal Mainali
- Bioinformatics Program, University of Arkansas for Medical Sciences and University of Arkansas at Little Rock, Little Rock, AR, 72205, USA
| | | | - Jay Johnson
- Bioinformatics Program, University of Arkansas for Medical Sciences and University of Arkansas at Little Rock, Little Rock, AR, 72205, USA
| | - Srinivas Ayyadevara
- Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
- McClellan Veterans Medical Center, Central Arkansas Veterans Healthcare Service, Little Rock, AR, 72205, USA
| | - Robert J. Shmookler Reis
- Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
- McClellan Veterans Medical Center, Central Arkansas Veterans Healthcare Service, Little Rock, AR, 72205, USA
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Balasubramaniam M, Ganne A, Mainali N, Pahal S, Ayyadevara S, Shmookler Reis RJ. Alzheimer's-specific brain amyloid interactome: Neural-network analysis of intra-aggregate crosslinking identifies novel drug targets. iScience 2024; 27:108745. [PMID: 38274404 PMCID: PMC10809092 DOI: 10.1016/j.isci.2023.108745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/15/2023] [Accepted: 12/12/2023] [Indexed: 01/27/2024] Open
Abstract
Alzheimer's disease (AD) is characterized by peri-neuronal amyloid plaque and intra-neuronal neurofibrillary tangles. These aggregates are identified by the immunodetection of "seed" proteins (Aβ1-42 and hyperphosphorylated tau, respectively), but include many other proteins incorporated nonrandomly. Using click-chemistry intra-aggregate crosslinking, we previously modeled amyloid "contactomes" in SY5Y-APPSw neuroblastoma cells, revealing that aspirin impedes aggregate growth and complexity. By an analogous strategy, we now construct amyloid-specific aggregate interactomes of AD and age-matched-control hippocampi. Comparing these interactomes reveals AD-specific interactions, from which neural-network (NN) analyses predict proteins with the highest impact on pathogenic aggregate formation and/or stability. RNAi knockdowns of implicated proteins, in C. elegans and human-cell-culture models of AD, validated those predictions. Gene-Ontology meta-analysis of AD-enriched influential proteins highlighted the involvement of mitochondrial and cytoplasmic compartments in AD-specific aggregation. This approach derives dynamic consensus models of aggregate growth and architecture, implicating highly influential proteins as new targets to disrupt amyloid accrual in the AD brain.
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Affiliation(s)
| | - Akshatha Ganne
- Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Nirjal Mainali
- Bioinformatics Program, University of Arkansas for Medical Sciences and University of Arkansas at Little Rock, Little Rock, AR 72205, USA
| | - Sonu Pahal
- Bioinformatics Program, University of Arkansas for Medical Sciences and University of Arkansas at Little Rock, Little Rock, AR 72205, USA
| | - Srinivas Ayyadevara
- Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- McClellan Veterans Medical Center, Central Arkansas Veterans Healthcare Service, Little Rock, AR 72205, USA
| | - Robert J. Shmookler Reis
- Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- McClellan Veterans Medical Center, Central Arkansas Veterans Healthcare Service, Little Rock, AR 72205, USA
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Wulff-Fuentes E, Boakye J, Kroenke K, Berendt RR, Martinez-Morant C, Pereckas M, Hanover JA, Olivier-Van Stichelen S. O-GlcNAcylation regulates OTX2's proteostasis. iScience 2023; 26:108184. [PMID: 38026167 PMCID: PMC10661118 DOI: 10.1016/j.isci.2023.108184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 08/28/2023] [Accepted: 10/09/2023] [Indexed: 12/01/2023] Open
Abstract
O-GlcNAcylation is a key post-translational modification, playing a vital role in cell signaling during development, especially in the brain. In this study, we investigated the role of O-GlcNAcylation in regulating the homeobox protein OTX2, which contributes to various brain disorders, such as combined pituitary hormone deficiency, retinopathy, and medulloblastoma. Our research demonstrated that, under normal physiological conditions, the proteasome plays a pivotal role in breaking down endogenous OTX2. However, when the levels of OTX2 rise, it forms oligomers and/or aggregates that require macroautophagy for clearance. Intriguingly, we demonstrated that O-GlcNAcylation enhances the solubility of OTX2, thereby limiting the formation of these aggregates. Additionally, we unveiled an interaction between OTX2 and the chaperone protein CCT5 at the O-GlcNAc sites, suggesting a potential collaborative role in preventing OTX2 aggregation. Finally, our study demonstrated that while OTX2 physiologically promotes cell proliferation, an O-GlcNAc-depleted OTX2 is detrimental to cancer cells.
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Affiliation(s)
| | - Jeffrey Boakye
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0851, USA
| | - Kaeley Kroenke
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Rex R. Berendt
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | | | - Michaela Pereckas
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - John A. Hanover
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0851, USA
| | - Stephanie Olivier-Van Stichelen
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Physiological Consequences of Targeting 14-3-3 and Its Interacting Partners in Neurodegenerative Diseases. Int J Mol Sci 2022; 23:ijms232415457. [PMID: 36555098 PMCID: PMC9779020 DOI: 10.3390/ijms232415457] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
The mammalian 14-3-3 family comprises seven intrinsically unstructured, evolutionarily conserved proteins that bind >200 protein targets, thereby modulating cell-signaling pathways. The presence of 14-3-3 proteins in cerebrospinal fluid provides a sensitive and specific biomarker of neuronal damage associated with Alzheimer’s disease (AD), Creutzfeldt−Jakob disease (CJD), spongiform encephalitis, brain cancers, and stroke. We observed significant enrichment of 14-3-3 paralogs G, S, and Z in human brain aggregates diagnostic of AD. We used intra-aggregate crosslinking to identify 14-3-3 interaction partners, all of which were significantly enriched in AD brain aggregates relative to controls. We screened FDA-approved drugs in silico for structures that could target the 14-3-3G/hexokinase interface, an interaction specific to aggregates and AD. C. elegans possesses only two 14-3-3 orthologs, which bind diverse proteins including DAF-16 (a FOXO transcription factor) and SIR-2.1 (a sensor of nutrients and stress), influencing lifespan. Top drug candidates were tested in C. elegans models of neurodegeneration-associated aggregation and in a human neuroblastoma cell-culture model of AD-like amyloidosis. Several drugs opposed aggregation in all models assessed and rescued behavioral deficits in C. elegans AD-like neuropathy models, suggesting that 14-3-3 proteins are instrumental in aggregate accrual and supporting the advancement of drugs targeting 14-3-3 protein complexes with their partners.
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Ganne A, Balasubramaniam M, Ayyadevara S, Shmookler Reis RJ. Machine-learning analysis of intrinsically disordered proteins identifies key factors that contribute to neurodegeneration-related aggregation. Front Aging Neurosci 2022; 14:938117. [PMID: 35992603 PMCID: PMC9382113 DOI: 10.3389/fnagi.2022.938117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
Protein structure is determined by the amino acid sequence and a variety of post-translational modifications, and provides the basis for physiological properties. Not all proteins in the proteome attain a stable conformation; roughly one third of human proteins are unstructured or contain intrinsically disordered regions exceeding 40% of their length. Proteins comprising or containing extensive unstructured regions are termed intrinsically disordered proteins (IDPs). IDPs are known to be overrepresented in protein aggregates of diverse neurodegenerative diseases. We evaluated the importance of disordered proteins in the nematode Caenorhabditis elegans, by RNAi-mediated knockdown of IDPs in disease-model strains that mimic aggregation associated with neurodegenerative pathologies. Not all disordered proteins are sequestered into aggregates, and most of the tested aggregate-protein IDPs contribute to important physiological functions such as stress resistance or reproduction. Despite decades of research, we still do not understand what properties of a disordered protein determine its entry into aggregates. We have employed machine-learning models to identify factors that predict whether a disordered protein is found in sarkosyl-insoluble aggregates isolated from neurodegenerative-disease brains (both AD and PD). Machine-learning predictions, coupled with principal component analysis (PCA), enabled us to identify the physiochemical properties that determine whether a disordered protein will be enriched in neuropathic aggregates.
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Affiliation(s)
- Akshatha Ganne
- Bioinformatics Program, University of Arkansas for Medical Sciences and University of Arkansas at Little Rock, Little Rock, AR, United States
| | | | - Srinivas Ayyadevara
- Bioinformatics Program, University of Arkansas for Medical Sciences and University of Arkansas at Little Rock, Little Rock, AR, United States
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States
- Central Arkansas Veterans Healthcare System, Little Rock, AR, United States
- *Correspondence: Srinivas Ayyadevara,
| | - Robert J. Shmookler Reis
- Bioinformatics Program, University of Arkansas for Medical Sciences and University of Arkansas at Little Rock, Little Rock, AR, United States
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States
- Central Arkansas Veterans Healthcare System, Little Rock, AR, United States
- Robert J. Shmookler Reis,
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Ganne A, Balasubramaniam M, Griffin WST, Shmookler Reis RJ, Ayyadevara S. Glial Fibrillary Acidic Protein: A Biomarker and Drug Target for Alzheimer’s Disease. Pharmaceutics 2022; 14:pharmaceutics14071354. [PMID: 35890250 PMCID: PMC9322874 DOI: 10.3390/pharmaceutics14071354] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 02/05/2023] Open
Abstract
Glial fibrillary acidic protein (GFAP) is an intermediate filament structural protein involved in cytoskeleton assembly and integrity, expressed in high abundance in activated glial cells. GFAP is neuroprotective, as knockout mice are hypersensitive to traumatic brain injury. GFAP in cerebrospinal fluid is a biomarker of Alzheimer’s disease (AD), dementia with Lewy bodies, and frontotemporal dementia (FTD). Here, we present novel evidence that GFAP is markedly overexpressed and differentially phosphorylated in AD hippocampus, especially in AD with the apolipoprotein E [ε4, ε4] genotype, relative to age-matched controls (AMCs). Kinases that phosphorylate GFAP are upregulated in AD relative to AMC. A knockdown of these kinases in SH-SY5Y-APPSw human neuroblastoma cells reduced amyloid accrual and lowered protein aggregation and associated behavioral traits in C. elegans models of polyglutamine aggregation (as observed in Huntington’s disease) and of Alzheimer’s-like amyloid formation. In silico screening of the ChemBridge structural library identified a small molecule, MSR1, with stable and specific binding to GFAP. Both MSR1 exposure and GF AP-specific RNAi knockdown reduce aggregation with remarkably high concordance of aggregate proteins depleted. These data imply that GFAP and its phosphorylation play key roles in neuropathic aggregate accrual and provide valuable new biomarkers, as well as novel therapeutic targets to alleviate, delay, or prevent AD.
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Affiliation(s)
- Akshatha Ganne
- Central Arkansas Veterans Healthcare Service, Little Rock, AR 72205, USA; (A.G.); (M.B.); (W.S.T.G.)
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | | | - W. Sue T. Griffin
- Central Arkansas Veterans Healthcare Service, Little Rock, AR 72205, USA; (A.G.); (M.B.); (W.S.T.G.)
- BioInformatics Program, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Robert J. Shmookler Reis
- Central Arkansas Veterans Healthcare Service, Little Rock, AR 72205, USA; (A.G.); (M.B.); (W.S.T.G.)
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- BioInformatics Program, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Department of Biochemistry & Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Correspondence: (R.J.S.R.); (S.A.); Tel.: +1-501-526-5820 (R.J.S.R.); +1-501-526-7282 (S.A.)
| | - Srinivas Ayyadevara
- Central Arkansas Veterans Healthcare Service, Little Rock, AR 72205, USA; (A.G.); (M.B.); (W.S.T.G.)
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- BioInformatics Program, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Correspondence: (R.J.S.R.); (S.A.); Tel.: +1-501-526-5820 (R.J.S.R.); +1-501-526-7282 (S.A.)
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Ayyadevara S, Ganne A, Balasubramaniam M, Shmookler Reis RJ. Intrinsically disordered proteins identified in the aggregate proteome serve as biomarkers of neurodegeneration. Metab Brain Dis 2022; 37:147-152. [PMID: 34347206 PMCID: PMC8748380 DOI: 10.1007/s11011-021-00791-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/04/2021] [Indexed: 11/26/2022]
Abstract
A protein's structure is determined by its amino acid sequence and post-translational modifications, and provides the basis for its physiological functions. Across all organisms, roughly a third of the proteome comprises proteins that contain highly unstructured or intrinsically disordered regions. Proteins comprising or containing extensive unstructured regions are referred to as intrinsically disordered proteins (IDPs). IDPs are believed to participate in complex physiological processes through refolding of IDP regions, dependent on their binding to a diverse array of potential protein partners. They thus play critical roles in the assembly and function of protein complexes. Recent advances in experimental and computational analyses predicted multiple interacting partners for the disordered regions of proteins, implying critical roles in signal transduction and regulation of biological processes. Numerous disordered proteins are sequestered into aggregates in neurodegenerative diseases such as Alzheimer's disease (AD) where they are enriched even in serum, making them good candidates for serum biomarkers to enable early detection of AD.
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Affiliation(s)
- Srinivas Ayyadevara
- Central Arkansas Veterans Healthcare Service, Little Rock, AR, 72205, USA.
- Reynolds Institute on Aging, Department of Geriatrics, University of Arkansas for Medical Sciences, 629 Jack Stephens Drive, Little Rock, AR, 72205, USA.
- BioInformatics Program, University of Arkansas at Little Rock and University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| | - Akshatha Ganne
- BioInformatics Program, University of Arkansas at Little Rock and University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Meenakshisundaram Balasubramaniam
- Reynolds Institute on Aging, Department of Geriatrics, University of Arkansas for Medical Sciences, 629 Jack Stephens Drive, Little Rock, AR, 72205, USA
| | - Robert J Shmookler Reis
- Central Arkansas Veterans Healthcare Service, Little Rock, AR, 72205, USA.
- Reynolds Institute on Aging, Department of Geriatrics, University of Arkansas for Medical Sciences, 629 Jack Stephens Drive, Little Rock, AR, 72205, USA.
- BioInformatics Program, University of Arkansas at Little Rock and University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
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Rybak-Wolf A, Plass M. RNA Dynamics in Alzheimer's Disease. Molecules 2021; 26:5113. [PMID: 34500547 PMCID: PMC8433936 DOI: 10.3390/molecules26175113] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder that heavily burdens healthcare systems worldwide. There is a significant requirement to understand the still unknown molecular mechanisms underlying AD. Current evidence shows that two of the major features of AD are transcriptome dysregulation and altered function of RNA binding proteins (RBPs), both of which lead to changes in the expression of different RNA species, including microRNAs (miRNAs), circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and messenger RNAs (mRNAs). In this review, we will conduct a comprehensive overview of how RNA dynamics are altered in AD and how this leads to the differential expression of both short and long RNA species. We will describe how RBP expression and function are altered in AD and how this impacts the expression of different RNA species. Furthermore, we will also show how changes in the abundance of specific RNA species are linked to the pathology of AD.
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Affiliation(s)
- Agnieszka Rybak-Wolf
- Max Delbrück Center for Molecular Medicine (MDC), Berlin Institute for Medical Systems Biology (BIMSB), 10115 Berlin, Germany
| | - Mireya Plass
- Gene Regulation of Cell Identity, Regenerative Medicine Program, Bellvitge Institute for Biomedical Research (IDIBELL), L'Hospitalet del Llobregat, 08908 Barcelona, Spain
- Program for Advancing Clinical Translation of Regenerative Medicine of Catalonia, P-CMR[C], L'Hospitalet del Llobregat, 08908 Barcelona, Spain
- Center for Networked Biomedical Research on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
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Shmookler Reis RJ, Atluri R, Balasubramaniam M, Johnson J, Ganne A, Ayyadevara S. "Protein aggregates" contain RNA and DNA, entrapped by misfolded proteins but largely rescued by slowing translational elongation. Aging Cell 2021; 20:e13326. [PMID: 33788386 PMCID: PMC8135009 DOI: 10.1111/acel.13326] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/12/2021] [Accepted: 02/01/2021] [Indexed: 01/03/2023] Open
Abstract
All neurodegenerative diseases feature aggregates, which usually contain disease-specific diagnostic proteins; non-protein constituents, however, have rarely been explored. Aggregates from SY5Y-APPSw neuroblastoma, a cell model of familial Alzheimer's disease, were crosslinked and sequences of linked peptides identified. We constructed a normalized "contactome" comprising 11 subnetworks, centered on 24 high-connectivity hubs. Remarkably, all 24 are nucleic acid-binding proteins. This led us to isolate and sequence RNA and DNA from Alzheimer's and control aggregates. RNA fragments were mapped to the human genome by RNA-seq and DNA by ChIP-seq. Nearly all aggregate RNA sequences mapped to specific genes, whereas DNA fragments were predominantly intergenic. These nucleic acid mappings are all significantly nonrandom, making an artifactual origin extremely unlikely. RNA (mostly cytoplasmic) exceeded DNA (chiefly nuclear) by twofold to fivefold. RNA fragments recovered from AD tissue were ~1.5-to 2.5-fold more abundant than those recovered from control tissue, similar to the increase in protein. Aggregate abundances of specific RNA sequences were strikingly differential between cultured SY5Y-APPSw glioblastoma cells expressing APOE3 vs. APOE4, consistent with APOE4 competition for E-box/CLEAR motifs. We identified many G-quadruplex and viral sequences within RNA and DNA of aggregates, suggesting that sequestration of viral genomes may have driven the evolution of disordered nucleic acid-binding proteins. After RNA-interference knockdown of the translational-procession factor EEF2 to suppress translation in SY5Y-APPSw cells, the RNA content of aggregates declined by >90%, while reducing protein content by only 30% and altering DNA content by ≤10%. This implies that cotranslational misfolding of nascent proteins may ensnare polysomes into aggregates, accounting for most of their RNA content.
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Affiliation(s)
- Robert J. Shmookler Reis
- Central Arkansas Veterans Healthcare System Little Rock AR USA
- Department of Geriatrics University of Arkansas for Medical Sciences Little Rock AR USA
- BioInformatics Program University of Arkansas for Medical Sciences and University of Arkansas at Little Rock Little Rock AR USA
| | - Ramani Atluri
- Department of Geriatrics University of Arkansas for Medical Sciences Little Rock AR USA
| | | | - Jay Johnson
- BioInformatics Program University of Arkansas for Medical Sciences and University of Arkansas at Little Rock Little Rock AR USA
| | - Akshatha Ganne
- BioInformatics Program University of Arkansas for Medical Sciences and University of Arkansas at Little Rock Little Rock AR USA
| | - Srinivas Ayyadevara
- Central Arkansas Veterans Healthcare System Little Rock AR USA
- Department of Geriatrics University of Arkansas for Medical Sciences Little Rock AR USA
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Aly KA, Moutaoufik MT, Phanse S, Zhang Q, Babu M. From fuzziness to precision medicine: on the rapidly evolving proteomics with implications in mitochondrial connectivity to rare human disease. iScience 2021; 24:102030. [PMID: 33521598 PMCID: PMC7820543 DOI: 10.1016/j.isci.2020.102030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mitochondrial (mt) dysfunction is linked to rare diseases (RDs) such as respiratory chain complex (RCC) deficiency, MELAS, and ARSACS. Yet, how altered mt protein networks contribute to these ailments remains understudied. In this perspective article, we identified 21 mt proteins from public repositories that associate with RCC deficiency, MELAS, or ARSACS, engaging in a relatively small number of protein-protein interactions (PPIs), underscoring the need for advanced proteomic and interactomic platforms to uncover the complete scope of mt connectivity to RDs. Accordingly, we discuss innovative untargeted label-free proteomics in identifying RD-specific mt or other macromolecular assemblies and mapping of protein networks in complex tissue, organoid, and stem cell-differentiated neurons. Furthermore, tag- and label-based proteomics, genealogical proteomics, and combinatorial affinity purification-mass spectrometry, along with advancements in detecting and integrating transient PPIs with single-cell proteomics and transcriptomics, collectively offer seminal follow-ups to enrich for RD-relevant networks, with implications in RD precision medicine.
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Affiliation(s)
- Khaled A. Aly
- Department of Biochemistry, University of Regina, Regina, SK, Canada
| | | | - Sadhna Phanse
- Department of Biochemistry, University of Regina, Regina, SK, Canada
| | - Qingzhou Zhang
- Department of Biochemistry, University of Regina, Regina, SK, Canada
| | - Mohan Babu
- Department of Biochemistry, University of Regina, Regina, SK, Canada
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Structural modeling of GSK3β implicates the inactive (DFG-out) conformation as the target bound by TDZD analogs. Sci Rep 2020; 10:18326. [PMID: 33110096 PMCID: PMC7591898 DOI: 10.1038/s41598-020-75020-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/21/2020] [Indexed: 02/06/2023] Open
Abstract
Glycogen synthase kinase-3β (GSK3β) controls many physiological pathways, and is implicated in many diseases including Alzheimer’s and several cancers. GSK3β-mediated phosphorylation of target residues in microtubule-associated protein tau (MAPTAU) contributes to MAPTAU hyperphosphorylation and subsequent formation of neurofibrillary tangles. Inhibitors of GSK3β protect against Alzheimer’s disease and are therapeutic for several cancers. A thiadiazolidinone drug, TDZD-8, is a non-ATP-competitive inhibitor targeting GSK3β with demonstrated efficacy against multiple diseases. However, no experimental data or models define the binding mode of TDZD-8 with GSK3β, which chiefly reflects our lack of an established inactive conformation for this protein. Here, we used metadynamic simulation to predict the three-dimensional structure of the inactive conformation of GSK3β. Our model predicts that phosphorylation of GSK3β Serine9 would hasten the DFG-flip to an inactive state. Molecular docking and simulation predict the TDZD-8 binding conformation of GSK3β to be inactive, and are consistent with biochemical evidence for the TDZD-8–interacting residues of GSK3β. We also identified the pharmacophore and assessed binding efficacy of second-generation TDZD analogs (TDZD-10 and Tideglusib) that bind GSK3β as non-ATP-competitive inhibitors. Based on these results, the predicted inactive conformation of GSK3β can facilitate the identification of novel GSK3β inhibitors of high potency and specificity.
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Zilocchi M, Moutaoufik MT, Jessulat M, Phanse S, Aly KA, Babu M. Misconnecting the dots: altered mitochondrial protein-protein interactions and their role in neurodegenerative disorders. Expert Rev Proteomics 2020; 17:119-136. [PMID: 31986926 DOI: 10.1080/14789450.2020.1723419] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Introduction: Mitochondria (mt) are protein-protein interaction (PPI) hubs in the cell where mt-localized and associated proteins interact in a fashion critical for cell fitness. Altered mtPPIs are linked to neurodegenerative disorders (NDs) and drivers of pathological associations to mediate ND progression. Mapping altered mtPPIs will reveal how mt dysfunction is linked to NDs.Areas covered: This review discusses how database sources reflect on the number of mt protein or interaction predictions, and serves as an update on mtPPIs in mt dynamics and homeostasis. Emphasis is given to mRNA expression profiles for mt proteins in human tissues, cellular models relevant to NDs, and altered mtPPIs in NDs such as Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD).Expert opinion: We highlight the scarcity of biomarkers to improve diagnostic accuracy and tracking of ND progression, obstacles in recapitulating NDs using human cellular models to underpin the pathophysiological mechanisms of disease, and the shortage of mt protein interactome reference database(s) of neuronal cells. These bottlenecks are addressed by improvements in induced pluripotent stem cell creation and culturing, patient-derived 3D brain organoids to recapitulate structural arrangements of the brain, and cell sorting to elucidate mt proteome disparities between cell types.
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Affiliation(s)
- Mara Zilocchi
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada
| | | | - Matthew Jessulat
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada
| | - Sadhna Phanse
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada
| | - Khaled A Aly
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada
| | - Mohan Babu
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada
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