1
|
Peng J, Liang D, Zhang Z. Palmitoylation of synaptic proteins: roles in functional regulation and pathogenesis of neurodegenerative diseases. Cell Mol Biol Lett 2024; 29:108. [PMID: 39127627 DOI: 10.1186/s11658-024-00625-2] [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: 05/10/2024] [Accepted: 07/30/2024] [Indexed: 08/12/2024] Open
Abstract
Palmitoylation is a type of lipid modification that plays an important role in various aspects of neuronal function. Over the past few decades, several studies have shown that the palmitoylation of synaptic proteins is involved in neurotransmission and synaptic functions. Palmitoyl acyltransferases (PATs), which belong to the DHHC family, are major players in the regulation of palmitoylation. Dysregulated palmitoylation of synaptic proteins and mutated/dysregulated DHHC proteins are associated with several neurodegenerative diseases, such as Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD). In this review, we summarize the recent discoveries on the subcellular distribution of DHHC proteins and analyze their expression patterns in different brain cells. In particular, this review discusses how palmitoylation of synaptic proteins regulates synaptic vesicle exocytotic fusion and the localization, clustering, and transport of several postsynaptic receptors, as well as the role of palmitoylation of other proteins in regulating synaptic proteins. Additionally, some of the specific known associations of these factors with neurodegenerative disorders are explored, with a few suggestions for the development of therapeutic strategies. Finally, this review provides possible directions for future research to reveal detailed and specific mechanisms underlying the roles of synaptic protein palmitoylation.
Collapse
Affiliation(s)
- Jiaying Peng
- Shenzhen Key Laboratory of Marine Bioresources and Ecology, Brain Disease and Big Data Research Institute, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Danchan Liang
- Shenzhen Key Laboratory of Marine Bioresources and Ecology, Brain Disease and Big Data Research Institute, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Zhonghao Zhang
- Shenzhen Key Laboratory of Marine Bioresources and Ecology, Brain Disease and Big Data Research Institute, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China.
- Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China.
| |
Collapse
|
2
|
Ramzan F, Abrar F, Mishra GG, Liao LMQ, Martin DDO. Lost in traffic: consequences of altered palmitoylation in neurodegeneration. Front Physiol 2023; 14:1166125. [PMID: 37324388 PMCID: PMC10268010 DOI: 10.3389/fphys.2023.1166125] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023] Open
Abstract
One of the first molecular events in neurodegenerative diseases, regardless of etiology, is protein mislocalization. Protein mislocalization in neurons is often linked to proteostasis deficiencies leading to the build-up of misfolded proteins and/or organelles that contributes to cellular toxicity and cell death. By understanding how proteins mislocalize in neurons, we can develop novel therapeutics that target the earliest stages of neurodegeneration. A critical mechanism regulating protein localization and proteostasis in neurons is the protein-lipid modification S-acylation, the reversible addition of fatty acids to cysteine residues. S-acylation is more commonly referred to as S-palmitoylation or simply palmitoylation, which is the addition of the 16-carbon fatty acid palmitate to proteins. Like phosphorylation, palmitoylation is highly dynamic and tightly regulated by writers (i.e., palmitoyl acyltransferases) and erasers (i.e., depalmitoylating enzymes). The hydrophobic fatty acid anchors proteins to membranes; thus, the reversibility allows proteins to be re-directed to and from membranes based on local signaling factors. This is particularly important in the nervous system, where axons (output projections) can be meters long. Any disturbance in protein trafficking can have dire consequences. Indeed, many proteins involved in neurodegenerative diseases are palmitoylated, and many more have been identified in palmitoyl-proteomic studies. It follows that palmitoyl acyl transferase enzymes have also been implicated in numerous diseases. In addition, palmitoylation can work in concert with cellular mechanisms, like autophagy, to affect cell health and protein modifications, such as acetylation, nitrosylation, and ubiquitination, to affect protein function and turnover. Limited studies have further revealed a sexually dimorphic pattern of protein palmitoylation. Therefore, palmitoylation can have wide-reaching consequences in neurodegenerative diseases.
Collapse
|
3
|
Beygmoradi A, Homaei A, Hemmati R, Fernandes P. Recombinant protein expression: Challenges in production and folding related matters. Int J Biol Macromol 2023; 233:123407. [PMID: 36708896 DOI: 10.1016/j.ijbiomac.2023.123407] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/13/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023]
Abstract
Protein folding is a biophysical process by which proteins reach a specific three-dimensional structure. The amino acid sequence of a polypeptide chain contains all the information needed to determine the final three-dimensional structure of a protein. When producing a recombinant protein, several problems can occur, including proteolysis, incorrect folding, formation of inclusion bodies, or protein aggregation, whereby the protein loses its natural structure. To overcome such limitations, several strategies have been developed to address each specific issue. Identification of proper protein refolding conditions can be challenging, and to tackle this high throughput screening for different recombinant protein folding conditions can prove a sound solution. Different approaches have emerged to tackle refolding issues. One particular approach to address folding issues involves molecular chaperones, highly conserved proteins that contribute to proper folding by shielding folding proteins from other proteins that could hinder the process. Proper protein folding is one of the main prerequisites for post-translational modifications. Incorrect folding, if not dealt with, can lead to a buildup of protein misfoldings that damage cells and cause widespread abnormalities. Said post-translational modifications, widespread in eukaryotes, are critical for protein structure, function and biological activity. Incorrect post-translational protein modifications may lead to individual consequences or aggregation of therapeutic proteins. In this review article, we have tried to examine some key aspects of recombinant protein expression. Accordingly, the relevance of these proteins is highlighted, major problems related to the production of recombinant protein and to refolding issues are pinpointed and suggested solutions are presented. An overview of post-translational modification, their biological significance and methods of identification are also provided. Overall, the work is expected to illustrate challenges in recombinant protein expression.
Collapse
Affiliation(s)
- Azadeh Beygmoradi
- Department of Marine Biology, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran
| | - Ahmad Homaei
- Department of Marine Biology, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran.
| | - Roohullah Hemmati
- Department of Biology, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran
| | - Pedro Fernandes
- DREAMS and Faculdade de Engenharia, Universidade Lusófona de Humanidades e Tecnologias, Av. Campo Grande 376, 1749-024 Lisboa, Portugal; iBB-Institute for Bioengineering and Biosciences and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| |
Collapse
|
4
|
Petropavlovskiy A, Kogut J, Leekha A, Townsend C, Sanders S. A sticky situation: regulation and function of protein palmitoylation with a spotlight on the axon and axon initial segment. Neuronal Signal 2021; 5:NS20210005. [PMID: 34659801 PMCID: PMC8495546 DOI: 10.1042/ns20210005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/19/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022] Open
Abstract
In neurons, the axon and axon initial segment (AIS) are critical structures for action potential initiation and propagation. Their formation and function rely on tight compartmentalisation, a process where specific proteins are trafficked to and retained at distinct subcellular locations. One mechanism which regulates protein trafficking and association with lipid membranes is the modification of protein cysteine residues with the 16-carbon palmitic acid, known as S-acylation or palmitoylation. Palmitoylation, akin to phosphorylation, is reversible, with palmitate cycling being mediated by substrate-specific enzymes. Palmitoylation is well-known to be highly prevalent among neuronal proteins and is well studied in the context of the synapse. Comparatively, how palmitoylation regulates trafficking and clustering of axonal and AIS proteins remains less understood. This review provides an overview of the current understanding of the biochemical regulation of palmitoylation, its involvement in various neurological diseases, and the most up-to-date perspective on axonal palmitoylation. Through a palmitoylation analysis of the AIS proteome, we also report that an overwhelming proportion of AIS proteins are likely palmitoylated. Overall, our review and analysis confirm a central role for palmitoylation in the formation and function of the axon and AIS and provide a resource for further exploration of palmitoylation-dependent protein targeting to and function at the AIS.
Collapse
Affiliation(s)
- Andrey A. Petropavlovskiy
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| | - Jordan A. Kogut
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| | - Arshia Leekha
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| | - Charlotte A. Townsend
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| | - Shaun S. Sanders
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| |
Collapse
|
5
|
Bandyopadhyay SS, Halder AK, Zaręba-Kozioł M, Bartkowiak-Kaczmarek A, Dutta A, Chatterjee P, Nasipuri M, Wójtowicz T, Wlodarczyk J, Basu S. RFCM-PALM: In-Silico Prediction of S-Palmitoylation Sites in the Synaptic Proteins for Male/Female Mouse Data. Int J Mol Sci 2021; 22:ijms22189901. [PMID: 34576064 PMCID: PMC8467992 DOI: 10.3390/ijms22189901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 11/16/2022] Open
Abstract
S-palmitoylation is a reversible covalent post-translational modification of cysteine thiol side chain by palmitic acid. S-palmitoylation plays a critical role in a variety of biological processes and is engaged in several human diseases. Therefore, identifying specific sites of this modification is crucial for understanding their functional consequences in physiology and pathology. We present a random forest (RF) classifier-based consensus strategy (RFCM-PALM) for predicting the palmitoylated cysteine sites on synaptic proteins from male/female mouse data. To design the prediction model, we have introduced a heuristic strategy for selection of the optimum set of physicochemical features from the AAIndex dataset using (a) K-Best (KB) features, (b) genetic algorithm (GA), and (c) a union (UN) of KB and GA based features. Furthermore, decisions from best-trained models of the KB, GA, and UN-based classifiers are combined by designing a three-star quality consensus strategy to further refine and enhance the scores of the individual models. The experiment is carried out on three categorized synaptic protein datasets of a male mouse, female mouse, and combined (male + female), whereas in each group, weighted data is used as training, and knock-out is used as the hold-out set for performance evaluation and comparison. RFCM-PALM shows ~80% area under curve (AUC) score in all three categories of datasets and achieve 10% average accuracy (male—15%, female—15%, and combined—7%) improvements on the hold-out set compared to the state-of-the-art approaches. To summarize, our method with efficient feature selection and novel consensus strategy shows significant performance gains in the prediction of S-palmitoylation sites in mouse datasets.
Collapse
Affiliation(s)
- Soumyendu Sekhar Bandyopadhyay
- Department of Computer Science and Engineering, Jadvapur University, Kolkata 700032, India; (S.S.B.); (A.K.H.); (A.D.); (M.N.)
- Department of Computer Science and Engineering, School of Engineering and Technology, Adamas University, Barasat, Kolkata 700126, India
| | - Anup Kumar Halder
- Department of Computer Science and Engineering, Jadvapur University, Kolkata 700032, India; (S.S.B.); (A.K.H.); (A.D.); (M.N.)
- Department of Computer Science and Engineering, University of Engineering & Management, Kolkata 700156, India
| | - Monika Zaręba-Kozioł
- The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.Z.-K.); (A.B.-K.); (T.W.)
| | - Anna Bartkowiak-Kaczmarek
- The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.Z.-K.); (A.B.-K.); (T.W.)
| | - Aviinandaan Dutta
- Department of Computer Science and Engineering, Jadvapur University, Kolkata 700032, India; (S.S.B.); (A.K.H.); (A.D.); (M.N.)
| | - Piyali Chatterjee
- Department of Computer Science and Engineering, Netaji Subhash Engineering College, Kolkata 700152, India;
| | - Mita Nasipuri
- Department of Computer Science and Engineering, Jadvapur University, Kolkata 700032, India; (S.S.B.); (A.K.H.); (A.D.); (M.N.)
| | - Tomasz Wójtowicz
- The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.Z.-K.); (A.B.-K.); (T.W.)
| | - Jakub Wlodarczyk
- The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.Z.-K.); (A.B.-K.); (T.W.)
- Correspondence: (J.W.); (S.B.)
| | - Subhadip Basu
- Department of Computer Science and Engineering, Jadvapur University, Kolkata 700032, India; (S.S.B.); (A.K.H.); (A.D.); (M.N.)
- Correspondence: (J.W.); (S.B.)
| |
Collapse
|
6
|
Ramazi S, Zahiri J. Posttranslational modifications in proteins: resources, tools and prediction methods. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2021; 2021:6214407. [PMID: 33826699 DOI: 10.1093/database/baab012] [Citation(s) in RCA: 284] [Impact Index Per Article: 94.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 02/20/2021] [Indexed: 12/21/2022]
Abstract
Posttranslational modifications (PTMs) refer to amino acid side chain modification in some proteins after their biosynthesis. There are more than 400 different types of PTMs affecting many aspects of protein functions. Such modifications happen as crucial molecular regulatory mechanisms to regulate diverse cellular processes. These processes have a significant impact on the structure and function of proteins. Disruption in PTMs can lead to the dysfunction of vital biological processes and hence to various diseases. High-throughput experimental methods for discovery of PTMs are very laborious and time-consuming. Therefore, there is an urgent need for computational methods and powerful tools to predict PTMs. There are vast amounts of PTMs data, which are publicly accessible through many online databases. In this survey, we comprehensively reviewed the major online databases and related tools. The current challenges of computational methods were reviewed in detail as well.
Collapse
Affiliation(s)
- Shahin Ramazi
- Bioinformatics and Computational Omics Lab (BioCOOL), Department of Biophysics, Faculty of Biological Sciences Tarbiat Modares University, Jalal Ale Ahmad Highway, P.O. Box: 14115-111, Tehran, Iran
| | - Javad Zahiri
- Bioinformatics and Computational Omics Lab (BioCOOL), Department of Biophysics, Faculty of Biological Sciences Tarbiat Modares University, Jalal Ale Ahmad Highway, P.O. Box: 14115-111, Tehran, Iran
- Department of Neuroscience, University of California San Diego, La Jolla, CA, USA
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
7
|
De Rossi P, Nomura T, Andrew RJ, Masse NY, Sampathkumar V, Musial TF, Sudwarts A, Recupero AJ, Le Metayer T, Hansen MT, Shim HN, Krause SV, Freedman DJ, Bindokas VP, Kasthuri N, Nicholson DA, Contractor A, Thinakaran G. Neuronal BIN1 Regulates Presynaptic Neurotransmitter Release and Memory Consolidation. Cell Rep 2021; 30:3520-3535.e7. [PMID: 32160554 PMCID: PMC7146643 DOI: 10.1016/j.celrep.2020.02.026] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 12/08/2019] [Accepted: 02/04/2020] [Indexed: 12/13/2022] Open
Abstract
BIN1, a member of the BAR adaptor protein family, is a significant late-onset Alzheimer disease risk factor. Here, we investigate BIN1 function in the brain using conditional knockout (cKO) models. Loss of neuronal Bin1 expression results in the select impairment of spatial learning and memory. Examination of hippocampal CA1 excitatory synapses reveals a deficit in presynaptic release probability and slower depletion of neurotransmitters during repetitive stimulation, suggesting altered vesicle dynamics in Bin1 cKO mice. Super-resolution and immunoelectron microscopy localizes BIN1 to presynaptic sites in excitatory synapses. Bin1 cKO significantly reduces synapse density and alters presynaptic active zone protein cluster formation. Finally, 3D electron microscopy reconstruction analysis uncovers a significant increase in docked and reserve pools of synaptic vesicles at hippocampal synapses in Bin1 cKO mice. Our results demonstrate a non-redundant role for BIN1 in presynaptic regulation, thus providing significant insights into the fundamental function of BIN1 in synaptic physiology relevant to Alzheimer disease. BIN1 is a significant risk factor for late-onset Alzheimer disease. BIN1 has a general role in endocytosis and membrane dynamics in non-neuronal cells. De Rossi et al. show that BIN1 localizes to presynaptic terminals and plays an indispensable role in excitatory synaptic transmission by regulating neurotransmitter vesicle dynamics.
Collapse
Affiliation(s)
- Pierre De Rossi
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - Toshihiro Nomura
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Robert J Andrew
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - Nicolas Y Masse
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | | | - Timothy F Musial
- Department of Neurological sciences, Rush University, Chicago, IL 60612, USA
| | - Ari Sudwarts
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA; Department of Molecular Medicine and Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA
| | | | - Thomas Le Metayer
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - Mitchell T Hansen
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA; Department of Molecular Medicine and Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA
| | - Ha-Na Shim
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - Sofia V Krause
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - David J Freedman
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - Vytas P Bindokas
- Integrated Light Microscopy Facility, The University of Chicago, Chicago, IL 60637, USA
| | - Narayanan Kasthuri
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - Daniel A Nicholson
- Department of Neurological sciences, Rush University, Chicago, IL 60612, USA
| | - Anis Contractor
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Chicago, IL, USA
| | - Gopal Thinakaran
- Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA; Department of Neurology, The University of Chicago, Chicago, IL 60637, USA; Department of Pathology, The University of Chicago, Chicago, IL 60637, USA; Department of Molecular Medicine and Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA.
| |
Collapse
|
8
|
Woodley KT, Collins MO. Regulation and function of the palmitoyl-acyltransferase ZDHHC5. FEBS J 2021; 288:6623-6634. [PMID: 33415776 DOI: 10.1111/febs.15709] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/19/2020] [Accepted: 01/06/2021] [Indexed: 01/22/2023]
Abstract
Protein palmitoylation (S-acylation) has emerged as an important player in a range of cellular processes, and as a result, the palmitoyl-acyltransferase (PAT) enzymes which mediate this modification have entered into the spotlight. Palmitoyltransferase ZDHHC5 (ZDHHC5) is among the more unique members of the PAT family as it is mainly localised to the plasma membrane and contains an extended cytoplasmic domain with several regulatory features. ZDHHC5 plays a vital role in a wide range of processes in different cell types. In this review, we offer a summary of the functions of ZDHHC5 in synaptic plasticity, cardiac function, cell adhesion and fatty acid uptake, among other processes. We also explore recent work has revealed several mechanisms to control the activity, localisation and function of ZDHHC5.
Collapse
Affiliation(s)
- Keith T Woodley
- Department of Biomedical Science & Centre for Membrane Interactions and Dynamics (CMIAD), Firth Court, Western Bank, University of Sheffield, UK.,Barts Cancer Institute, John Vane Science Centre, Queen Mary University of London, UK
| | - Mark O Collins
- Department of Biomedical Science & Centre for Membrane Interactions and Dynamics (CMIAD), Firth Court, Western Bank, University of Sheffield, UK
| |
Collapse
|
9
|
Wang X, Yin Z, Cao P, Zheng S, Chen Y, Yu M, Liao C, Zhang Z, Duan Y, Han J, Zhang S, Yang X. NaoXinTong Capsule ameliorates memory deficit in APP/PS1 mice by regulating inflammatory cytokines. Biomed Pharmacother 2021; 133:110964. [PMID: 33197761 DOI: 10.1016/j.biopha.2020.110964] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/18/2020] [Accepted: 11/01/2020] [Indexed: 11/21/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease in aging population. Neuroinflammation, hyperphosphorylated Tau (p-Tau) and the imbalance between production and clearance of β-amyloid peptide (Aβ) are the major causes for AD development. NaoXinTong Capsule (NXT), a traditional Chinese medicine, is wildly used for treatment of cardiovascular and cerebrovascular diseases. Hence, we used the double transgenic mice expressing chimeric human amyloid precursor protein and mutant human presenilin 1 (APP/PS1) and HT-22 cells to determine the neuroprotective effects of NXT in AD development and the involved mechanisms. The 3-month-old APP/PS1 mice were randomly divided into 3 groups and received following treatment: Control group, mice were fed normal chow; NXT groups, mice were fed normal chow containing NXT at a normal and a high dose, respectively. While the age-matched C57BL/6J mice fed normal chow were used as the normal control. The NXT treatment was lasted for 5 months. We found that NXT treatment improved spatial memory impairment and cognitive decline in APP/PS1 mice by decreasing p-Tau levels and Aβ accumulation in the brain. Mechanistically, we observed that NXT inhibited neuron atrophy and apoptosis by downregulating inflammatory cytokines, interleukin 1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α), and inflammation mediators, nuclear factor κB (NF-κB) and toll-like receptor 4 (TLR4) in the brain. Consistently, NXT blocked l-glutamic acid-induced reactive oxygen species production, inflammation and apoptosis in HT-22 cells partially by inhibiting TLR4/NF-κB/IL-1β signaling pathway. Our study demonstrates that NXT ameliorates AD by reducing p-Tau, Aβ accumulation, inflammation and neuron apoptosis via regulation of TLR4-mediated inflammatory system. It also suggests the potential application of NXT for AD treatment.
Collapse
Affiliation(s)
- Xuerui Wang
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China
| | - Zequn Yin
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China
| | - Peichang Cao
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China
| | - Shihong Zheng
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China
| | - Yuanli Chen
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China
| | - Maoyun Yu
- School of Biological and Pharmaceutical Engineering, West Anhui University, Lu'an, China
| | - Chenzhong Liao
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China
| | | | - Yajun Duan
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China
| | - Jihong Han
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China; College of Life Sciences, Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of Ministry of Education, Nankai University, Tianjin, China
| | - Shuang Zhang
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China.
| | - Xiaoxiao Yang
- Key Laboratory of Metabolism and Regulation for Major Diseases of Anhui Higher Education Institutes, College of Food and Biological Engineering, Hefei University of Technology, Hefei, China.
| |
Collapse
|
10
|
Wu Z, Tan R, Zhu L, Yao P, Hu Q. Protein S-Palmitoylation and Lung Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1304:165-186. [PMID: 34019269 DOI: 10.1007/978-3-030-68748-9_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
S-palmitoylation of protein is a posttranslational, reversible lipid modification; it was catalyzed by a family of 23 mammalian palmitoyl acyltransferases in humans. S-palmitoylation can impact protein function by regulating protein sorting, secretion, trafficking, stability, and protein interaction. Thus, S-palmitoylation plays a crucial role in many human diseases including mental illness and cancers. In this chapter, we systematically reviewed the influence of S-palmitoylation on protein performance, the characteristics of S-palmitoylation regulating protein function, and the role of S-palmitoylation in pulmonary inflammation and pulmonary hypertension and summed up the treatment strategies of S-palmitoylation-related diseases and the research status of targeted S-palmitoylation agonists/inhibitors. In conclusion, we highlighted the potential role of S-palmitoylation and depalmitoylation in the treatment of human diseases.
Collapse
Affiliation(s)
- Zeang Wu
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China.,School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rubin Tan
- School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,School of Basic Medicine, Xuzhou Medical University, Xuzhou, China
| | - Liping Zhu
- School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ping Yao
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Qinghua Hu
- School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| |
Collapse
|
11
|
Ramesh M, Gopinath P, Govindaraju T. Role of Post-translational Modifications in Alzheimer's Disease. Chembiochem 2020; 21:1052-1079. [PMID: 31863723 DOI: 10.1002/cbic.201900573] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/19/2019] [Indexed: 12/22/2022]
Abstract
The global burden of Alzheimer's disease (AD) is growing. Valiant efforts to develop clinical candidates for treatment have continuously met with failure. Currently available palliative treatments are temporary and there is a constant need to search for reliable disease pathways, biomarkers and drug targets for developing diagnostic and therapeutic tools to address the unmet medical needs of AD. Challenges in drug-discovery efforts raise further questions about the strategies of current conventional diagnosis; drug design; and understanding of disease pathways, biomarkers and targets. In this context, post-translational modifications (PTMs) regulate protein trafficking, function and degradation, and their in-depth study plays a significant role in the identification of novel biomarkers and drug targets. Aberrant PTMs of disease-relevant proteins could trigger pathological pathways, leading to disease progression. Advancements in proteomics enable the generation of patterns or signatures of such modifications, and thus, provide a versatile platform to develop biomarkers based on PTMs. In addition, understanding and targeting the aberrant PTMs of various proteins provide viable avenues for addressing AD drug-discovery challenges. This review highlights numerous PTMs of proteins relevant to AD and provides an overview of their adverse effects on the protein structure, function and aggregation propensity that contribute to the disease pathology. A critical discussion offers suggestions of methods to develop PTM signatures and interfere with aberrant PTMs to develop viable diagnostic and therapeutic interventions in AD.
Collapse
Affiliation(s)
- Madhu Ramesh
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur P.O., Bengaluru, 560064, Karnataka, India
| | - Pushparathinam Gopinath
- Department of Chemistry, SRM-Institute of Science and Technology, Kattankulathur, 603203, Chennai, Tamilnadu, India
| | - Thimmaiah Govindaraju
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur P.O., Bengaluru, 560064, Karnataka, India
| |
Collapse
|
12
|
Xu XF, Wang YC, Zong L, Wang XL. miR-151-5p modulates APH1a expression to participate in contextual fear memory formation. RNA Biol 2019; 16:282-294. [PMID: 30663934 DOI: 10.1080/15476286.2019.1572435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Long-term memory formation requires gene expression and new protein synthesis. MicroRNAs (miRNAs), a family of small non-coding RNAs that inhibit target gene mRNA expression, are involved in new memory formation. In this study, elevated miR-151-5p (miR-151) levels were found to be responsible for hippocampal contextual fear memory formation. Using a luciferase reporter assay, we demonstrated that miR-151 targets APH1a, a protein that has been identified as a key factor in γ-secretase activity, namely APH1a. Blocking miR-151 can upregulate APH1a protein levels and subsequently impair hippocampal fear memory formation. These results indicate that miR-151 is involved in hippocampal contextual fear memory by inhibiting APH1a protein expression. This work provides novel evidence for the role of miRNAs in memory formation and demonstrates the implication of APH1a protein in miRNA processing in the adult brain.
Collapse
Affiliation(s)
- Xu-Feng Xu
- a Institute of Brain Science and Disease, School of Basic Medicine , Qingdao University , Qingdao , Shandong , People's Republic of China.,b The Royal, Department of Psychiatry, and Department of Cellular and Molecular Medicine , University of Ottawa Institute of Mental Health Research , Ottawa , Canada.,c Department of Cell and Neurobiology , School of Basic Medicine, Shandong University , Jinan , Shandong , People's Republic of China
| | - You-Cui Wang
- a Institute of Brain Science and Disease, School of Basic Medicine , Qingdao University , Qingdao , Shandong , People's Republic of China
| | - Liang Zong
- d BGI-Shenzhen , Shenzhen , People's Republic of China
| | - Xiao-Long Wang
- e Department of Breast Surgery , Qilu hospital, Shandong University , Jinan , Shandong , People's Republic of China
| |
Collapse
|
13
|
Rajagopal N, Irudayanathan FJ, Nangia S. Palmitoylation of Claudin-5 Proteins Influences Their Lipid Domain Affinity and Tight Junction Assembly at the Blood–Brain Barrier Interface. J Phys Chem B 2019; 123:983-993. [DOI: 10.1021/acs.jpcb.8b09535] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Nandhini Rajagopal
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse 13244, United States
| | | | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse 13244, United States
| |
Collapse
|
14
|
Rudd AK, Brea RJ, Devaraj NK. Amphiphile-Mediated Depalmitoylation of Proteins in Living Cells. J Am Chem Soc 2018; 140:17374-17378. [PMID: 30516377 DOI: 10.1021/jacs.8b10806] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Post-translational S-palmitoylation plays a central role in protein localization, trafficking, stability, aggregation, and cell signaling. Dysregulation of palmitoylation pathways in cells can alter protein function and is the cause of several diseases. Considering the biological and clinical importance of S-palmitoylation, tools for direct, in vivo modulation of this lipid modification would be extremely valuable. Here, we describe a method for the cleavage of native S-palmitoyl groups from proteins in living cells. Using a cell permeable, cysteine-functionalized amphiphile, we demonstrate the direct depalmitoylation of cellular proteins. We show that amphiphile-mediated depalmitoylation (AMD) can effectively cleave S-palmitoyl groups from the native GTPase HRas and successfully depalmitoylate mislocalized proteins in an infantile neuronal ceroid lipofuscinosis (INCL) disease model. AMD enables direct and facile depalmitoylation of proteins in live cells and has potential therapeutic applications for diseases such as INCL, where native protein thioesterase activity is deficient.
Collapse
Affiliation(s)
- Andrew K Rudd
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Roberto J Brea
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Neal K Devaraj
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| |
Collapse
|
15
|
Khan I, Krishnaswamy S, Sabale M, Groth D, Wijaya L, Morici M, Berger I, Schaffitzel C, Fraser PE, Martins RN, Verdile G. Efficient production of a mature and functional gamma secretase protease. Sci Rep 2018; 8:12834. [PMID: 30150752 PMCID: PMC6110731 DOI: 10.1038/s41598-018-30788-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 08/06/2018] [Indexed: 12/27/2022] Open
Abstract
Baculoviral protein expression in insect cells has been previously used to generate large quantities of a protein of interest for subsequent use in biochemical and structural analyses. The MultiBac baculovirus protein expression system has enabled, the use of a single baculovirus to reconstitute a protein complex of interest, resulting in a larger protein yield. Using this system, we aimed to reconstruct the gamma (γ)-secretase complex, a multiprotein enzyme complex essential for the production of amyloid-β (Aβ) protein. A MultiBac vector containing all components of the γ-secretase complex was generated and expression was observed for all components. The complex was active in processing APP and Notch derived γ-secretase substrates and proteolysis could be inhibited with γ-secretase inhibitors, confirming specificity of the recombinant γ-secretase enzyme. Finally, affinity purification was used to purify an active recombinant γ-secretase complex. In this study we demonstrated that the MultiBac protein expression system can be used to generate an active γ-secretase complex and provides a new tool to study γ-secretase enzyme and its variants.
Collapse
Affiliation(s)
- Imran Khan
- School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia. .,School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, Western Australia, Australia. .,Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.
| | - Sudarsan Krishnaswamy
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Miheer Sabale
- School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - David Groth
- School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Linda Wijaya
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.,School of Psychology and Exercise Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Michael Morici
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, Western Australia, Australia.,Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Imre Berger
- European Molecular Biology Laboratories, Grenoble, France.,School of Biochemistry, University of Bristol, Bristol, UK
| | - Christiane Schaffitzel
- European Molecular Biology Laboratories, Grenoble, France.,School of Biochemistry, University of Bristol, Bristol, UK
| | - Paul E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases and Department of Medical Biophysics, Krembil Discovery Tower, University of Toronto, Toronto, Ontario, Canada
| | - Ralph N Martins
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, Western Australia, Australia.,Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.,Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Giuseppe Verdile
- School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia. .,School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, Western Australia, Australia. .,Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.
| |
Collapse
|
16
|
Carta G, Murru E, Banni S, Manca C. Palmitic Acid: Physiological Role, Metabolism and Nutritional Implications. Front Physiol 2017; 8:902. [PMID: 29167646 PMCID: PMC5682332 DOI: 10.3389/fphys.2017.00902] [Citation(s) in RCA: 380] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 10/24/2017] [Indexed: 12/19/2022] Open
Abstract
Palmitic acid (PA) has been for long time negatively depicted for its putative detrimental health effects, shadowing its multiple crucial physiological activities. PA is the most common saturated fatty acid accounting for 20–30% of total fatty acids in the human body and can be provided in the diet or synthesized endogenously via de novo lipogenesis (DNL). PA tissue content seems to be controlled around a well-defined concentration, and changes in its intake do not influence significantly its tissue concentration because the exogenous source is counterbalanced by PA endogenous biosynthesis. Particular physiopathological conditions and nutritional factors may strongly induce DNL, resulting in increased tissue content of PA and disrupted homeostatic control of its tissue concentration. The tight homeostatic control of PA tissue concentration is likely related to its fundamental physiological role to guarantee membrane physical properties but also to consent protein palmitoylation, palmitoylethanolamide (PEA) biosynthesis, and in the lung an efficient surfactant activity. In order to maintain membrane phospholipids (PL) balance may be crucial an optimal intake of PA in a certain ratio with unsaturated fatty acids, especially PUFAs of both n-6 and n-3 families. However, in presence of other factors such as positive energy balance, excessive intake of carbohydrates (in particular mono and disaccharides), and a sedentary lifestyle, the mechanisms to maintain a steady state of PA concentration may be disrupted leading to an over accumulation of tissue PA resulting in dyslipidemia, hyperglycemia, increased ectopic fat accumulation and increased inflammatory tone via toll-like receptor 4. It is therefore likely that the controversial data on the association of dietary PA with detrimental health effects, may be related to an excessive imbalance of dietary PA/PUFA ratio which, in certain physiopathological conditions, and in presence of an enhanced DNL, may further accelerate these deleterious effects.
Collapse
Affiliation(s)
- Gianfranca Carta
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Elisabetta Murru
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Sebastiano Banni
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Claudia Manca
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| |
Collapse
|
17
|
Lack of BACE1 S-palmitoylation reduces amyloid burden and mitigates memory deficits in transgenic mouse models of Alzheimer's disease. Proc Natl Acad Sci U S A 2017; 114:E9665-E9674. [PMID: 29078331 DOI: 10.1073/pnas.1708568114] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by pathological brain lesions and a decline in cognitive function. β-Amyloid peptides (Aβ), derived from proteolytic processing of amyloid precursor protein (APP), play a central role in AD pathogenesis. β-Site APP cleaving enzyme 1 (BACE1), the transmembrane aspartyl protease which initiates Aβ production, is axonally transported in neurons and accumulates in dystrophic neurites near cerebral amyloid deposits in AD. BACE1 is modified by S-palmitoylation at four juxtamembrane cysteine residues. S-palmitoylation is a dynamic posttranslational modification that is important for trafficking and function of several synaptic proteins. Here, we investigated the in vivo significance of BACE1 S-palmitoylation through the analysis of knock-in mice with cysteine-to-alanine substitution at the palmitoylated residues (4CA mice). BACE1 expression, as well as processing of APP and other neuronal substrates, was unaltered in 4CA mice despite the lack of BACE1 S-palmitoylation and reduced lipid raft association. Whereas steady-state Aβ levels were similar, synaptic activity-induced endogenous Aβ production was not observed in 4CA mice. Furthermore, we report a significant reduction of cerebral amyloid burden and BACE1 accumulation in dystrophic neurites in the absence of BACE1 S-palmitoylation in mouse models of AD amyloidosis. Studies in cultured neurons suggest that S-palmitoylation is required for dendritic spine localization and axonal targeting of BACE1. Finally, the lack of BACE1 S-palmitoylation mitigates cognitive deficits in 5XFAD mice. Using transgenic mouse models, these results demonstrate that intrinsic posttranslational S-palmitoylation of BACE1 has a significant impact on amyloid pathogenesis and the consequent cognitive decline.
Collapse
|
18
|
Dyer RR, Gu L, Robinson RAS. S-Nitrosylation in Alzheimer’s Disease Using Oxidized Cysteine-Selective cPILOT. NEUROMETHODS 2017. [DOI: 10.1007/978-1-4939-7119-0_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
19
|
Bhattacharyya R, Fenn RH, Barren C, Tanzi RE, Kovacs DM. Palmitoylated APP Forms Dimers, Cleaved by BACE1. PLoS One 2016; 11:e0166400. [PMID: 27875558 PMCID: PMC5119739 DOI: 10.1371/journal.pone.0166400] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 10/30/2016] [Indexed: 11/26/2022] Open
Abstract
A major rate-limiting step for Aβ generation and deposition in Alzheimer's disease brains is BACE1-mediated cleavage (β-cleavage) of the amyloid precursor protein (APP). We previously reported that APP undergoes palmitoylation at two cysteine residues (Cys186 and Cys187) in the E1-ectodomain. 8-10% of total APP is palmitoylated in vitro and in vivo. Palmitoylated APP (palAPP) shows greater preference for β-cleavage than total APP in detergent resistant lipid rafts. Protein palmitoylation is known to promote protein dimerization. Since dimerization of APP at its E1-ectodomain results in elevated BACE1-mediated cleavage of APP, we have now investigated whether palmitoylation of APP affects its dimerization and whether this leads to elevated β-cleavage of the protein. Here we report that over 90% of palAPP is dimerized while only ~20% of total APP forms dimers. PalAPP-dimers are predominantly cis-oriented while total APP dimerizes in both cis- and trans-orientation. PalAPP forms dimers 4.5-times more efficiently than total APP. Overexpression of the palmitoylating enzymes DHHC7 and DHHC21 that increase palAPP levels and Aβ release, also increased APP dimerization in cells. Conversely, inhibition of APP palmitoylation by pharmacological inhibitors reduced APP-dimerization in coimmunoprecipitation and FLIM/FRET assays. Finally, in vitro BACE1-activity assays demonstrate that palmitoylation-dependent dimerization of APP promotes β-cleavage of APP in lipid-rich detergent resistant cell membranes (DRMs), when compared to total APP. Most importantly, generation of sAPPβ-sAPPβ dimers is dependent on APP-palmitoylation while total sAPPβ generation is not. Since BACE1 shows preference for palAPP dimers over total APP, palAPP dimers may serve as novel targets for effective β-cleavage inhibitors of APP as opposed to BACE1 inhibitors.
Collapse
Affiliation(s)
- Raja Bhattacharyya
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, United States of America
| | - Rebecca H. Fenn
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, United States of America
| | - Cory Barren
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, United States of America
| | - Rudolph E. Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, United States of America
| | - Dora M. Kovacs
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, United States of America
| |
Collapse
|
20
|
Cho E, Park M. Palmitoylation in Alzheimers disease and other neurodegenerative diseases. Pharmacol Res 2016; 111:133-151. [DOI: 10.1016/j.phrs.2016.06.008] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 06/07/2016] [Accepted: 06/08/2016] [Indexed: 12/13/2022]
|
21
|
Ellgaard L, McCaul N, Chatsisvili A, Braakman I. Co- and Post-Translational Protein Folding in the ER. Traffic 2016; 17:615-38. [PMID: 26947578 DOI: 10.1111/tra.12392] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 02/26/2016] [Accepted: 03/03/2016] [Indexed: 12/19/2022]
Abstract
The biophysical rules that govern folding of small, single-domain proteins in dilute solutions are now quite well understood. The mechanisms underlying co-translational folding of multidomain and membrane-spanning proteins in complex cellular environments are often less clear. The endoplasmic reticulum (ER) produces a plethora of membrane and secretory proteins, which must fold and assemble correctly before ER exit - if these processes fail, misfolded species accumulate in the ER or are degraded. The ER differs from other cellular organelles in terms of the physicochemical environment and the variety of ER-specific protein modifications. Here, we review chaperone-assisted co- and post-translational folding and assembly in the ER and underline the influence of protein modifications on these processes. We emphasize how method development has helped advance the field by allowing researchers to monitor the progression of folding as it occurs inside living cells, while at the same time probing the intricate relationship between protein modifications during folding.
Collapse
Affiliation(s)
- Lars Ellgaard
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Nicholas McCaul
- Cellular Protein Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Anna Chatsisvili
- Cellular Protein Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Ineke Braakman
- Cellular Protein Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
22
|
The Deleterious Effects of Oxidative and Nitrosative Stress on Palmitoylation, Membrane Lipid Rafts and Lipid-Based Cellular Signalling: New Drug Targets in Neuroimmune Disorders. Mol Neurobiol 2015; 53:4638-58. [PMID: 26310971 DOI: 10.1007/s12035-015-9392-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Accepted: 08/11/2015] [Indexed: 12/18/2022]
Abstract
Oxidative and nitrosative stress (O&NS) is causatively implicated in the pathogenesis of Alzheimer's and Parkinson's disease, multiple sclerosis, chronic fatigue syndrome, schizophrenia and depression. Many of the consequences stemming from O&NS, including damage to proteins, lipids and DNA, are well known, whereas the effects of O&NS on lipoprotein-based cellular signalling involving palmitoylation and plasma membrane lipid rafts are less well documented. The aim of this narrative review is to discuss the mechanisms involved in lipid-based signalling, including palmitoylation, membrane/lipid raft (MLR) and n-3 polyunsaturated fatty acid (PUFA) functions, the effects of O&NS processes on these processes and their role in the abovementioned diseases. S-palmitoylation is a post-translational modification, which regulates protein trafficking and association with the plasma membrane, protein subcellular location and functions. Palmitoylation and MRLs play a key role in neuronal functions, including glutamatergic neurotransmission, and immune-inflammatory responses. Palmitoylation, MLRs and n-3 PUFAs are vulnerable to the corruptive effects of O&NS. Chronic O&NS inhibits palmitoylation and causes profound changes in lipid membrane composition, e.g. n-3 PUFA depletion, increased membrane permeability and reduced fluidity, which together lead to disorders in intracellular signal transduction, receptor dysfunction and increased neurotoxicity. Disruption of lipid-based signalling is a source of the neuroimmune disorders involved in the pathophysiology of the abovementioned diseases. n-3 PUFA supplementation is a rational therapeutic approach targeting disruptions in lipid-based signalling.
Collapse
|
23
|
Li S, Li J, Ning L, Wang S, Niu Y, Jin N, Yao X, Liu H, Xi L. In Silico Identification of Protein S-Palmitoylation Sites and Their Involvement in Human Inherited Disease. J Chem Inf Model 2015; 55:2015-25. [PMID: 26274591 DOI: 10.1021/acs.jcim.5b00276] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
| | | | | | | | | | - Nengzhi Jin
- Department
of Technical Support, Gansu Computing Centre, Lanzhou, 730000, China
| | | | | | - Lili Xi
- Department
of Pharmacy, First Hospital of Lanzhou University, Lanzhou, 730000, China
| |
Collapse
|
24
|
Sanders SS, Martin DDO, Butland SL, Lavallée-Adam M, Calzolari D, Kay C, Yates JR, Hayden MR. Curation of the Mammalian Palmitoylome Indicates a Pivotal Role for Palmitoylation in Diseases and Disorders of the Nervous System and Cancers. PLoS Comput Biol 2015; 11:e1004405. [PMID: 26275289 PMCID: PMC4537140 DOI: 10.1371/journal.pcbi.1004405] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/16/2015] [Indexed: 12/12/2022] Open
Abstract
Palmitoylation involves the reversible posttranslational addition of palmitate to cysteines and promotes membrane binding and subcellular localization. Recent advancements in the detection and identification of palmitoylated proteins have led to multiple palmitoylation proteomics studies but these datasets are contained within large supplemental tables, making downstream analysis and data mining time-consuming and difficult. Consequently, we curated the data from 15 palmitoylation proteomics studies into one compendium containing 1,838 genes encoding palmitoylated proteins; representing approximately 10% of the genome. Enrichment analysis revealed highly significant enrichments for Gene Ontology biological processes, pathway maps, and process networks related to the nervous system. Strikingly, 41% of synaptic genes encode a palmitoylated protein in the compendium. The top disease associations included cancers and diseases and disorders of the nervous system, with Schizophrenia, HD, and pancreatic ductal carcinoma among the top five, suggesting that aberrant palmitoylation may play a pivotal role in the balance of cell death and survival. This compendium provides a much-needed resource for cell biologists and the palmitoylation field, providing new perspectives for cancer and neurodegeneration. Protein localization is essential for mediating protein function within the cellular context. Mislocalization of proteins can offset cellular balance, influencing whether a cell lives or dies. Many proteins are directed to cellular membranes through the addition of fats, or lipidation. In particular, palmitoylation involves the reversible addition of the fatty acid palmitate to cysteines. Its reversibility makes it a unique form of lipidation allowing its dynamic regulation. Recent advancements in fast, sensitive, non-radioactive methods to detect palmitoylation have led to an explosion in the identification of palmitoylated proteins through proteomics studies. However, the data is hidden in large supplemental tables in various formats. Thus, we curated a list of palmitoylated proteins revealing that approximately 10 percent of the human genome encodes for a proteoform that is palmitoylated. Computational analysis confirmed that palmitoylation is involved in protein localization and indicated a new role in metabolism. Importantly, we found that palmitoylation was enriched at neuronal synapses and in disorders of the nervous system, including Schizophrenia and Huntington disease. Interestingly, palmitoylation was equally enriched in cancers. Consequently, we suggest that palmitoylation plays a critical role in cell fate and our compendium provides a plethora of targets for neurodegeneration and cancer.
Collapse
Affiliation(s)
- Shaun S. Sanders
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dale D. O. Martin
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
| | - Stefanie L. Butland
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mathieu Lavallée-Adam
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Diego Calzolari
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Chris Kay
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - John R. Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
25
|
Takasugi N, Sasaki T, Shinohara M, Iwatsubo T, Tomita T. Synthetic ceramide analogues increase amyloid-β 42 production by modulating γ-secretase activity. Biochem Biophys Res Commun 2015; 457:194-9. [DOI: 10.1016/j.bbrc.2014.12.087] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Accepted: 12/19/2014] [Indexed: 01/02/2023]
|
26
|
|
27
|
Palmitoylation of amyloid precursor protein regulates amyloidogenic processing in lipid rafts. J Neurosci 2013; 33:11169-83. [PMID: 23825420 DOI: 10.1523/jneurosci.4704-12.2013] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Brains of patients affected by Alzheimer's disease (AD) contain large deposits of aggregated amyloid β-protein (Aβ). Only a small fraction of the amyloid precursor protein (APP) gives rise to Aβ. Here, we report that ∼10% of APP undergoes a post-translational lipid modification called palmitoylation. We identified the palmitoylation sites in APP at Cys¹⁸⁶ and Cys¹⁸⁷. Surprisingly, point mutations introduced into these cysteines caused nearly complete ER retention of APP. Thus, either APP palmitoylation or disulfide bridges involving these Cys residues appear to be required for ER exit of APP. In later compartments, palmitoylated APP (palAPP) was specifically enriched in lipid rafts. In vitro BACE1 cleavage assays using cell or mouse brain lipid rafts showed that APP palmitoylation enhanced BACE1-mediated processing of APP. Interestingly, we detected an age-dependent increase in endogenous mouse brain palAPP levels. Overexpression of selected DHHC palmitoyl acyltransferases increased palmitoylation of APP and doubled Aβ production, while two palmitoylation inhibitors reduced palAPP levels and APP processing. We have found previously that acyl-coenzyme A:cholesterol acyltransferase (ACAT) inhibition led to impaired APP processing. Here we demonstrate that pharmacological inhibition or genetic inactivation of ACAT decrease lipid raft palAPP levels by up to 76%, likely resulting in impaired APP processing. Together, our results indicate that APP palmitoylation enhances amyloidogenic processing by targeting APP to lipid rafts and enhancing its BACE1-mediated cleavage. Thus, inhibition of palAPP formation by ACAT or specific palmitoylation inhibitors would appear to be a valid strategy for prevention and/or treatment of AD.
Collapse
|
28
|
Zeiger W, Vetrivel KS, Buggia-Prévot V, Nguyen PD, Wagner SL, Villereal ML, Thinakaran G. Ca2+ influx through store-operated Ca2+ channels reduces Alzheimer disease β-amyloid peptide secretion. J Biol Chem 2013; 288:26955-66. [PMID: 23902769 DOI: 10.1074/jbc.m113.473355] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alzheimer disease (AD), the leading cause of dementia, is characterized by the accumulation of β-amyloid peptides (Aβ) in senile plaques in the brains of affected patients. Many cellular mechanisms are thought to play important roles in the development and progression of AD. Several lines of evidence point to the dysregulation of Ca(2+) homeostasis as underlying aspects of AD pathogenesis. Moreover, direct roles in the regulation of Ca(2+) homeostasis have been demonstrated for proteins encoded by familial AD-linked genes such as PSEN1, PSEN2, and APP, as well as Aβ peptides. Whereas these studies support the hypothesis that disruption of Ca(2+) homeostasis contributes to AD, it is difficult to disentangle the effects of familial AD-linked genes on Aβ production from their effects on Ca(2+) homeostasis. Here, we developed a system in which cellular Ca(2+) homeostasis could be directly manipulated to study the effects on amyloid precursor protein metabolism and Aβ production. We overexpressed stromal interaction molecule 1 (STIM1) and Orai1, the components of the store-operated Ca(2+) entry pathway, to generate cells with constitutive and store depletion-induced Ca(2+) entry. We found striking effects of Ca(2+) entry induced by overexpression of the constitutively active STIM1(D76A) mutant on amyloid precursor protein metabolism. Specifically, constitutive activation of Ca(2+) entry by expression of STIM1(D76A) significantly reduced Aβ secretion. Our results suggest that disruptions in Ca(2+) homeostasis may influence AD pathogenesis directly through the modulation of Aβ production.
Collapse
Affiliation(s)
- William Zeiger
- From the Departments of Neurobiology, Neurology, and Pathology and
| | | | | | | | | | | | | |
Collapse
|
29
|
Blaskovic S, Blanc M, van der Goot FG. What does S-palmitoylation do to membrane proteins? FEBS J 2013; 280:2766-74. [PMID: 23551889 DOI: 10.1111/febs.12263] [Citation(s) in RCA: 182] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 03/20/2013] [Accepted: 03/25/2013] [Indexed: 12/19/2022]
Abstract
S-palmitoylation is post-translational modification, which consists in the addition of a C16 acyl chain to cytosolic cysteines and which is unique amongst lipid modifications in that it is reversible. It can thus, like phosphorylation or ubiquitination, act as a switch. While palmitoylation of soluble proteins allows them to interact with membranes, the consequences of palmitoylation for transmembrane proteins are more enigmatic. We briefly review the current knowledge regarding the enzymes responsible for palmitate addition and removal. We then describe various observed consequences of membrane protein palmitoylation. We propose that the direct effects of palmitoylation on transmembrane proteins, however, might be limited to four non-mutually exclusive mechanistic consequences: alterations in the conformation of transmembrane domains, association with specific membrane domains, controlled interactions with other proteins and controlled interplay with other post-translational modifications.
Collapse
Affiliation(s)
- Sanja Blaskovic
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Switzerland
| | | | | |
Collapse
|
30
|
Young FB, Butland SL, Sanders SS, Sutton LM, Hayden MR. Putting proteins in their place: Palmitoylation in Huntington disease and other neuropsychiatric diseases. Prog Neurobiol 2012; 97:220-38. [DOI: 10.1016/j.pneurobio.2011.11.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 11/01/2011] [Accepted: 11/08/2011] [Indexed: 01/02/2023]
|
31
|
Gong P, Roseman J, Fernandez CG, Vetrivel KS, Bindokas VP, Zitzow LA, Kar S, Parent AT, Thinakaran G. Transgenic neuronal overexpression reveals that stringently regulated p23 expression is critical for coordinated movement in mice. Mol Neurodegener 2011; 6:87. [PMID: 22204304 PMCID: PMC3259059 DOI: 10.1186/1750-1326-6-87] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 12/28/2011] [Indexed: 11/24/2022] Open
Abstract
Background p23 belongs to the highly conserved p24 family of type I transmembrane proteins, which participate in the bidirectional protein transport between the endoplasmic reticulum and Golgi apparatus. Mammalian p23 has been shown to interact with γ-secretase complex, and modulate secretory trafficking as well as intramembranous processing of amyloid precursor protein in cultured cells. Negative modulation of β-amyloid production by p23 in cultured cell lines suggested that elevation of p23 expression in neurons might mitigate cerebral amyloid burden. Results We generated several lines of transgenic mice expressing human p23 in neurons under the control of Thy-1.2 promoter. We found that even a 50% increase in p23 levels in the central nervous system of mice causes post-natal growth retardation, severe neurological problems characterized by tremors, seizure, ataxia, and uncoordinated movements, and premature death. The severity of the phenotype closely correlated with the level of p23 overexpression in multiple transgenic lines. While the number and general morphology of neurons in Hup23 mice appeared to be normal throughout the brain, abnormal non-Golgi p23 localization was observed in a subset of neurons with high transgene expression in brainstem. Moreover, detailed immunofluorescence analysis revealed marked proliferation of astrocytes, activation of microglia, and thinning of myelinated bundles in brainstem of Hup23 mice. Conclusions These results demonstrate that proper level of p23 expression is critical for neuronal function, and perturbing p23 function by overexpression initiates a cascade of cellular reactions in brainstem that leads to severe motor deficits and other neurological problems, which culminate in premature death. The neurological phenotype observed in Hup23 mice highlights significant adverse effects associated with manipulating neuronal expression of p23, a previously described negative modulator of γ-secretase activity and β-amyloid production. Moreover, our report has broader relevance to molecular mechanisms in several neurodegenerative diseases as it highlights the inherent vulnerability of the early secretory pathway mechanisms that ensure proteostasis in neurons.
Collapse
Affiliation(s)
- Ping Gong
- Departments of Neurobiology, Neurology, and Pathology, The University of Chicago, Chicago, IL 60637, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Li T, Li YM, Ahn K, Price DL, Sisodia SS, Wong PC. Increased expression of PS1 is sufficient to elevate the level and activity of γ-secretase in vivo. PLoS One 2011; 6:e28179. [PMID: 22140537 PMCID: PMC3226664 DOI: 10.1371/journal.pone.0028179] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 11/02/2011] [Indexed: 11/18/2022] Open
Abstract
Increase in the generation and deposition of amyloid-β (Aβ) plays a central role in the development of Alzheimer's Disease (AD). Elevation of the activity of γ-secretase, a key enzyme required for the generation for Aβ, can thus be a potential risk factor in AD. However, it is not known whether γ-secretase can be upregulated in vivo. While in vitro studies showed that expression of all four components of γ-secretase (Nicastrin, Presenilin, Pen-2 and Aph-1) are required for upregulation of γ-secretase, it remains to be established as to whether this is true in vivo. To investigate whether overexpressing a single component of the γ-secretase complex is sufficient to elevate its level and activity in the brain, we analyzed transgenic mice expressing either wild type or familial AD (fAD) associated mutant PS1. In contrast to cell culture studies, overexpression of either wild type or mutant PS1 is sufficient to increase levels of Nicastrin and Pen-2, and elevate the level of active γ-secretase complex, enzymatic activity of γ-secretase and the deposition of Aβ in brains of mice. Importantly, γ-secretase comprised of mutant PS1 is less active than that of wild type PS1-containing γ-secretase; however, γ-secretase comprised of mutant PS1 cleaves at the Aβ42 site of APP-CTFs more efficiently than at the Aβ40 site, resulting in greater accumulation of Aβ deposits in the brain. Our data suggest that whereas fAD-linked PS1 mutants cause early onset disease, upregulation of PS1/γ-secretase activity may be a risk factor for late onset sporadic AD.
Collapse
Affiliation(s)
- Tong Li
- Department of Pathology, The Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America.
| | | | | | | | | | | |
Collapse
|
33
|
Karve TM, Cheema AK. Small changes huge impact: the role of protein posttranslational modifications in cellular homeostasis and disease. JOURNAL OF AMINO ACIDS 2011; 2011:207691. [PMID: 22312457 PMCID: PMC3268018 DOI: 10.4061/2011/207691] [Citation(s) in RCA: 231] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 04/18/2011] [Indexed: 01/08/2023]
Abstract
Posttranslational modifications (PTMs) modulate protein function in most eukaryotes and have a ubiquitous role in diverse range of cellular functions. Identification, characterization, and mapping of these modifications to specific amino acid residues on proteins are critical towards understanding their functional significance in a biological context. The interpretation of proteome data obtained from the high-throughput methods cannot be deciphered unambiguously without a priori knowledge of protein modifications. An in-depth understanding of protein PTMs is important not only for gaining a perception of a wide array of cellular functions but also towards developing drug therapies for many life-threatening diseases like cancer and neurodegenerative disorders. Many of the protein modifications like ubiquitination play a decisive role in various drug response(s) and eventually in disease prognosis. Thus, many commonly observed PTMs are routinely tracked as disease markers while many others are used as molecular targets for developing target-specific therapies. In this paper, we summarize some of the major, well-studied protein alterations and highlight their importance in various chronic diseases and normal development. In addition, other promising minor modifications such as SUMOylation, observed to impact cellular dynamics as well as disease pathology, are mentioned briefly.
Collapse
Affiliation(s)
- Tejaswita M Karve
- Department of Biochemistry, Cellular & Molecular Biology, Lombardi Comprehensive Cancer Center, Georgetown University School of Medicine, 3900 Reservoir Road, NW, Washington DC 20057, USA
| | | |
Collapse
|
34
|
Abstract
The regulation of cellular Ca(2+) homeostasis is essential for innumerable physiological and pathological processes. Stanniocalcin 1, a secreted glycoprotein hormone originally described in fish, is a well-established endocrine regulator of gill Ca(2+) uptake during hypercalcemia. While there are two mammalian Stanniocalcin homologs (STC1 and STC2), their precise molecular functions remain unknown. Notably, STC2 is a prosurvival component of the unfolded protein response. Here, we demonstrate a cell-intrinsic role for STC2 in the regulation of store-operated Ca(2+) entry (SOCE). Fibroblasts cultured from Stc2 knockout mice accumulate higher levels of cytosolic Ca(2+) following endoplasmic reticulum (ER) Ca(2+) store depletion, specifically due to an increase in extracellular Ca(2+) influx through store-operated Ca(2+) channels (SOC). The knockdown of STC2 expression in a hippocampal cell line also potentiates SOCE, and the overexpression of STC2 attenuates SOCE. Moreover, STC2 interacts with the ER Ca(2+) sensor STIM1, which activates SOCs following ER store depletion. These results define a novel molecular function for STC2 as a negative modulator of SOCE and provide the first direct evidence for the regulation of Ca(2+) homeostasis by mammalian STC2. Furthermore, our findings implicate the modulation of SOCE through STC2 expression as one of the prosurvival measures of the unfolded protein response.
Collapse
|