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Devi S, Charvat A, Millbern Z, Vinueza N, Gestwicki JE. Exploration of the binding determinants of protein phosphatase 5 (PP5) reveals a chaperone-independent activation mechanism. J Biol Chem 2024; 300:107435. [PMID: 38830406 DOI: 10.1016/j.jbc.2024.107435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/10/2024] [Accepted: 05/23/2024] [Indexed: 06/05/2024] Open
Abstract
The protein phosphatase 5 (PP5) is normally recruited to its substrates by the molecular chaperones, heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90). This interaction requires the tetratricopeptide repeat (TPR) domain of PP5, which binds to an EEVD motif at the extreme C termini of cytosolic Hsp70 and Hsp90 isoforms. In addition to bringing PP5 into proximity with chaperone-bound substrates, this interaction also relieves autoinhibition in PP5's catalytic domain, promoting its phosphatase activity. To better understand the molecular determinants of this process, we screened a large, pentapeptide library for binding to PP5. This screen identified the amino acid preferences at each position, which we validated by showing that the optimal sequences bind 4- to 7-fold tighter than the natural EEVD motifs and stimulate PP5's enzymatic activity. The enhanced affinity for PP5's TPR domain was confirmed using a protein-adaptive differential scanning fluorimetry assay. Using this increased knowledge of structure-activity relationships, we re-examined affinity proteomics results to look for potential EEVD-like motifs in the C termini of known PP5-binding partners. This search identified elongator acetyltransferase complex subunit 1 (IKBKAP) as a putative partner, and indeed, we found that its C-terminal sequence, LSLLD, binds directly to PP5's TPR domain in vitro. Consistent with this idea, mutation of elongator acetyltransferase complex subunit 1's terminal aspartate was sufficient to interrupt the interaction with PP5 in vitro and in cells. Together, these findings reveal the sequence preferences of PP5's TPR domain and expand the scope of PP5's functions to include chaperone-independent complexes.
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Affiliation(s)
- Shweta Devi
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, USA
| | - Annemarie Charvat
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, USA
| | - Zoe Millbern
- Department of Textile Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Nelson Vinueza
- Department of Textile Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, USA.
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2
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Ahanin EF, Sager RA, Backe SJ, Dunn DM, Dushukyan N, Blanden AR, Mate NA, Suzuki T, Anderson T, Roy M, Oberoi J, Prodromou C, Nsouli I, Daneshvar M, Bratslavsky G, Woodford MR, Bourboulia D, Chisholm JD, Mollapour M. Catalytic inhibitor of Protein Phosphatase 5 activates the extrinsic apoptotic pathway by disrupting complex II in kidney cancer. Cell Chem Biol 2023; 30:1223-1234.e12. [PMID: 37527661 PMCID: PMC10592443 DOI: 10.1016/j.chembiol.2023.06.026] [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: 03/08/2023] [Revised: 05/11/2023] [Accepted: 06/30/2023] [Indexed: 08/03/2023]
Abstract
Serine/threonine protein phosphatase-5 (PP5) is involved in tumor progression and survival, making it an attractive therapeutic target. Specific inhibition of protein phosphatases has remained challenging because of their conserved catalytic sites. PP5 contains its regulatory domains within a single polypeptide chain, making it a more desirable target. Here we used an in silico approach to screen and develop a selective inhibitor of PP5. Compound P053 is a competitive inhibitor of PP5 that binds to its catalytic domain and causes apoptosis in renal cancer. We further demonstrated that PP5 interacts with FADD, RIPK1, and caspase 8, components of the extrinsic apoptotic pathway complex II. Specifically, PP5 dephosphorylates and inactivates the death effector protein FADD, preserving complex II integrity and regulating extrinsic apoptosis. Our data suggests that PP5 promotes renal cancer survival by suppressing the extrinsic apoptotic pathway. Pharmacologic inhibition of PP5 activates this pathway, presenting a viable therapeutic strategy for renal cancer.
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Affiliation(s)
- Elham F Ahanin
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Rebecca A Sager
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Sarah J Backe
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Diana M Dunn
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Natela Dushukyan
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Adam R Blanden
- Department of Neurology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Nilamber A Mate
- Department of Chemistry, Syracuse University, Syracuse, NY 13210, USA
| | - Tamie Suzuki
- Department of Chemistry, Syracuse University, Syracuse, NY 13210, USA
| | - Tyler Anderson
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; College of Health Professions, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Merin Roy
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Jasmeen Oberoi
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK
| | - Chrisostomos Prodromou
- School of Life Sciences, Biochemistry and Biomedicine, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Imad Nsouli
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Michael Daneshvar
- Department of Urology, University of California, California, Irvine, CA 92868, USA
| | - Gennady Bratslavsky
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Mark R Woodford
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Dimitra Bourboulia
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
| | - John D Chisholm
- Department of Chemistry, Syracuse University, Syracuse, NY 13210, USA.
| | - Mehdi Mollapour
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
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3
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van Oosten-Hawle P. A new chink in cancer's armor: Unleashing cell death by selective PP5 inhibition. Cell Chem Biol 2023; 30:1186-1188. [PMID: 37863031 DOI: 10.1016/j.chembiol.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 08/28/2023] [Accepted: 09/02/2023] [Indexed: 10/22/2023]
Abstract
Serine/threonine protein phosphatases play a significant role in the survival and propagation of multiple cancers. In this issue of Cell Chemical Biology, Ahanin et al.1 demonstrate that protein phosphatase 5 (PP5) dephosphorylates and inactivates the cell death effector protein FADD independently of Hsp90, and they identify a selective PP5 inhibitor as a new therapeutic strategy for renal cancer.
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4
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Gu W, Zheng H, Canessa CM. Phosphatases maintain low catalytic activity of SGK1: DNA damage resets the balance in favor of phosphorylation. J Biol Chem 2023; 299:104941. [PMID: 37343701 PMCID: PMC10372406 DOI: 10.1016/j.jbc.2023.104941] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/23/2023] Open
Abstract
The serum- and glucocorticoid-induced kinase 1 (SGK1) promotes cell survival under stress conditions and facilitates the emergence of drug resistance in cancer. The underlying mechanisms of these observations are not fully understood. In this study, we found that SGK1 activity is suppressed by the action of the S/T phosphatases PP5 and PP2A, which constantly dephosphorylate SGK1. Using newly developed anti-phospho SGK1 antibodies and inhibitors of phosphatases, we determined that the high degree of dephosphorylation is caused by two factors: the tendency of SGK1 to unfold, which makes it dependent on Hsp90 chaperone complexes composed of four proteins, Hsp90/CDC37/PP5/SGK1, and where the phosphatase PP5 persistently dephosphorylates SGK1 within the complex. SGK1 binding to PP2A regulatory subunits B55γ and B55δ brings PP2A catalytic subunit close to exposed SGK1 phosphoresidues. A further association of phosphorylated pS37-FAM122A-an endogenous inhibitor of PP2A-to the holoenzyme diminishes dephosphorylation of SGK1 mediated by PP2A. Our study also reveals that genotoxic stress can reverse the dominant impact of phosphatases over kinases by activating the DNA-dependent protein kinase, which enhances mTORC2 activity directed to SGK1. Thus, our results provide insight into a molecular pathway that enables SGK1 to gain phosphorylation and catalytic activity and promote cell survival, potentially diminishing the efficacy of cancer treatments. As the DNA damage response operates in many cancer cells and is further induced by chemotherapies, the findings of this study could have significant implications for the development of novel cancer therapies targeting SGK1.
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Affiliation(s)
- Wenxue Gu
- School of Medicine, Tsinghua University, Beijing, China
| | - Hongyan Zheng
- School of Medicine, Tsinghua University, Beijing, China
| | - Cecilia M Canessa
- School of Medicine, Tsinghua University, Beijing, China; Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, USA.
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5
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Som N, Reddy M. Cross-talk between phospholipid synthesis and peptidoglycan expansion by a cell wall hydrolase. Proc Natl Acad Sci U S A 2023; 120:e2300784120. [PMID: 37276399 PMCID: PMC10268279 DOI: 10.1073/pnas.2300784120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 05/04/2023] [Indexed: 06/07/2023] Open
Abstract
The Gram-negative bacterial cell envelope is a complex multilayered structure comprising a bilayered phospholipid (PL) membrane that surrounds the cytoplasm (inner membrane or IM) and an asymmetric outer membrane (OM) with PLs in the inner leaflet and lipopolysaccharides in the outer leaflet. Between these two layers is the periplasmic space, which contains a highly cross-linked mesh-like glycan polymer, peptidoglycan (PG). During cell expansion, coordinated synthesis of each of these components is required to maintain the integrity of the cell envelope; however, it is currently not clear how such coordination is achieved. In this study, we show that a cross-link-specific PG hydrolase couples the expansion of PG sacculus with that of PL synthesis in the Gram-negative model bacterium, Escherichia coli. We find that unregulated activity of a PG hydrolytic enzyme, MepS is detrimental for growth of E. coli during fatty acid (FA)-limiting conditions. Further genetic and biochemical analyses revealed that cellular availability of FA or PL alters the post-translational stability of MepS by modulating the proteolytic activity of a periplasmic adaptor-protease complex, NlpI-Prc toward MepS. Our results indicate that loss of OM lipid asymmetry caused by alterations in PL abundance leads to the generation of a signal to the NlpI-Prc complex for the stabilization of MepS, which subsequently cleaves the cross-links to facilitate expansion of PG. In summary, our study shows the existence of a molecular cross-talk that enables coordinated expansion of the PG sacculus with that of membrane synthesis for balanced cell-envelope biogenesis.
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Affiliation(s)
- Nilanjan Som
- Centre for Cellular and Molecular Biology, Hyderabad, 500007Telangana, India
| | - Manjula Reddy
- Centre for Cellular and Molecular Biology, Hyderabad, 500007Telangana, India
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6
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Shikha K, Madhumal Thayil V, Shahi JP, Zaidi PH, Seetharam K, Nair SK, Singh R, Tosh G, Singamsetti A, Singh S, Sinha B. Genomic-regions associated with cold stress tolerance in Asia-adapted tropical maize germplasm. Sci Rep 2023; 13:6297. [PMID: 37072497 PMCID: PMC10113201 DOI: 10.1038/s41598-023-33250-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 04/10/2023] [Indexed: 05/03/2023] Open
Abstract
Maize is gaining impetus in non-traditional and non-conventional seasons such as off-season, primarily due to higher demand and economic returns. Maize varieties directed for growing in the winter season of South Asia must have cold resilience as an important trait due to the low prevailing temperatures and frequent cold snaps observed during this season in most parts of the lowland tropics of Asia. The current study involved screening of a panel of advanced tropically adapted maize lines to cold stress during vegetative and flowering stage under field conditions. A suite of significant genomic loci (28) associated with grain yield along and agronomic traits such as flowering (15) and plant height (6) under cold stress environments. The haplotype regression revealed 6 significant haplotype blocks for grain yield under cold stress across the test environments. Haplotype blocks particularly on chromosomes 5 (bin5.07), 6 (bin6.02), and 9 (9.03) co-located to regions/bins that have been identified to contain candidate genes involved in membrane transport system that would provide essential tolerance to the plant. The regions on chromosome 1 (bin1.04), 2 (bin 2.07), 3 (bin 3.05-3.06), 5 (bin5.03), 8 (bin8.05-8.06) also harboured significant SNPs for the other agronomic traits. In addition, the study also looked at the plausibility of identifying tropically adapted maize lines from the working germplasm with cold resilience across growth stages and identified four lines that could be used as breeding starts in the tropical maize breeding pipelines.
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Affiliation(s)
- Kumari Shikha
- Department of Genetics and Plant Breeding, Banaras Hindu University (BHU), Varanasi, India
| | - Vinayan Madhumal Thayil
- International Maize and Wheat Improvement Centre (CIMMYT), ICRISAT Campus, Patancheru, Telangana, India.
| | - J P Shahi
- Department of Genetics and Plant Breeding, Banaras Hindu University (BHU), Varanasi, India
| | - P H Zaidi
- International Maize and Wheat Improvement Centre (CIMMYT), ICRISAT Campus, Patancheru, Telangana, India
| | - Kaliyamoorthy Seetharam
- International Maize and Wheat Improvement Centre (CIMMYT), ICRISAT Campus, Patancheru, Telangana, India
| | - Sudha K Nair
- International Maize and Wheat Improvement Centre (CIMMYT), ICRISAT Campus, Patancheru, Telangana, India
| | - Raju Singh
- Borlaug Institute for South Asia (BISA), Ludhiana, Punjab, India
| | - Garg Tosh
- Punjab Agricultural University (PAU), Ludhiana, India
| | - Ashok Singamsetti
- Department of Genetics and Plant Breeding, Banaras Hindu University (BHU), Varanasi, India
| | - Saurabh Singh
- Department of Genetics and Plant Breeding, Banaras Hindu University (BHU), Varanasi, India
| | - B Sinha
- Department of Genetics and Plant Breeding, Banaras Hindu University (BHU), Varanasi, India
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7
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Jaime-Garza M, Nowotny CA, Coutandin D, Wang F, Tabios M, Agard DA. Hsp90 provides a platform for kinase dephosphorylation by PP5. Nat Commun 2023; 14:2197. [PMID: 37069154 PMCID: PMC10110553 DOI: 10.1038/s41467-023-37659-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 03/23/2023] [Indexed: 04/19/2023] Open
Abstract
The Hsp90 molecular chaperone collaborates with the phosphorylated Cdc37 cochaperone for the folding and activation of its many client kinases. As with many kinases, the Hsp90 client kinase CRaf is activated by phosphorylation at specific regulatory sites. The cochaperone phosphatase PP5 dephosphorylates CRaf and Cdc37 in an Hsp90-dependent manner. Although dephosphorylating Cdc37 has been proposed as a mechanism for releasing Hsp90-bound kinases, here we show that Hsp90 bound kinases sterically inhibit Cdc37 dephosphorylation indicating kinase release must occur before Cdc37 dephosphorylation. Our cryo-EM structure of PP5 in complex with Hsp90:Cdc37:CRaf reveals how Hsp90 both activates PP5 and scaffolds its association with the bound CRaf to dephosphorylate phosphorylation sites neighboring the kinase domain. Thus, we directly show how Hsp90's role in maintaining protein homeostasis goes beyond folding and activation to include post translationally modifying its client kinases.
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Affiliation(s)
- Maru Jaime-Garza
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Carlos A Nowotny
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Daniel Coutandin
- Novartis Institutes for BioMedical Research, San Diego, CA, 92121, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Mariano Tabios
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - David A Agard
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94143, USA.
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8
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Zhang H, Zhang Q, Tu J, You Q, Wang L. Dual function of protein phosphatase 5 (PPP5C): An emerging therapeutic target for drug discovery. Eur J Med Chem 2023; 254:115350. [PMID: 37054560 DOI: 10.1016/j.ejmech.2023.115350] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/21/2023] [Accepted: 03/28/2023] [Indexed: 04/15/2023]
Abstract
Phosphorylation of proteins is reversibly controlled by the kinases and phosphatases in many posttranslational regulation patterns. Protein phosphatase 5 (PPP5C) is a serine/threonine protein phosphatase showing dual function by simultaneously exerting dephosphorylation and co-chaperone functions. Due to this special role, PPP5C was found to participate in many signal transductions related to various diseases. Abnormal expression of PPP5C results in cancers, obesity, and Alzheimer's disease, making it a potential drug target. However, the design of small molecules targeting PPP5C is struggling due to its special monomeric enzyme form and low basal activity by a self-inhibition mechanism. Through realizing the PPP5C's dual function as phosphatase and co-chaperone, more and more small molecules were found to regulate PPP5C with a different mechanism. This review aims to provide insights into PPP5C's dual function from structure to function, which could provide efficient design strategies for small molecules targeting PPP5C as therapeutic candidates.
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Affiliation(s)
- Hengheng Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Qiuyue Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Jiaqi Tu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Qidong You
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, China.
| | - Lei Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, China.
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9
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Zhang Q, Wu X, Zhang H, Wu Q, Fu M, Hua L, Zhu X, Guo Y, Zhang L, You Q, Wang L. Protein Phosphatase 5-Recruiting Chimeras for Accelerating Apoptosis-Signal-Regulated Kinase 1 Dephosphorylation with Antiproliferative Activity. J Am Chem Soc 2023; 145:1118-1128. [PMID: 36546850 DOI: 10.1021/jacs.2c10759] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A normal phosphorylation state is essential for the function of proteins. Biased regulation frequently results in morbidity, especially for the hyperphosphorylation of oncoproteins. The hyperphosphorylation of ASK1 at Thr838 leads to a persistently high activity state, which accelerates the course of gastric cancer. Under normal conditions, PP5 specifically dephosphorylates p-ASK1T838 in cells, thereby weakening ASK1 to a low-basal activity state. However, in tumor types, PP5 shows low activity with a self-inhibition mechanism, making p-ASK1T838 remain at a high level. Thus, we aim to design phosphatase recruitment chimeras (PHORCs) through a proximity-mediated effect for specifically accelerating the dephosphorylation of p-ASK1T838. Herein, we describe DDO3711 as the first PP5-recruiting PHORC, which is formed by connecting a small molecular ASK1 inhibitor to a PP5 activator through a chemical linker, to effectively decrease the level of p-ASK1T838 in vitro and in vivo. DDO3711 shows preferable antiproliferative activity (IC50 = 0.5 μM) against MKN45 cells through a direct binding and proximity-mediated mechanism, while the ASK1 inhibitor and the PP5 activator, used alone or in combination, exhibit no effect on MKN45 cells. Using DDO3711, PHORCs are identified as effective tools to accelerate the dephosphorylation of POIs and provide important evidence to achieve precise phosphorylation regulation, which will promote confidence in the further regulation of abnormally phosphorylated oncoproteins.
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Affiliation(s)
- Qiuyue Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Xuexuan Wu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Hengheng Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Qiuyu Wu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Min Fu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Liwen Hua
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Xinyue Zhu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yuqi Guo
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Lianshan Zhang
- Shanghai Hengrui Pharmaceutical Co., Ltd., Shanghai 200245, China
| | - Qidong You
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Lei Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China.,Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
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10
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Saini LK, Bheri M, Pandey GK. Protein phosphatases and their targets: Comprehending the interactions in plant signaling pathways. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 134:307-370. [PMID: 36858740 DOI: 10.1016/bs.apcsb.2022.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Protein phosphorylation is a vital reversible post-translational modification. This process is established by two classes of enzymes: protein kinases and protein phosphatases. Protein kinases phosphorylate proteins while protein phosphatases dephosphorylate phosphorylated proteins, thus, functioning as 'critical regulators' in signaling pathways. The eukaryotic protein phosphatases are classified as phosphoprotein phosphatases (PPP), metallo-dependent protein phosphatases (PPM), protein tyrosine (Tyr) phosphatases (PTP), and aspartate (Asp)-dependent phosphatases. The PPP and PPM families are serine (Ser)/threonine (Thr) specific phosphatases (STPs) that dephosphorylate Ser and Thr residues. The PTP family dephosphorylates Tyr residues while dual-specificity phosphatases (DsPTPs/DSPs) dephosphorylate Ser, Thr, and Tyr residues. The composition of these enzymes as well as their substrate specificity are important determinants of their functional significance in a number of cellular processes and stress responses. Their role in animal systems is well-understood and characterized. The functional characterization of protein phosphatases has been extensively covered in plants, although the comprehension of their mechanistic basis is an ongoing pursuit. The nature of their interactions with other key players in the signaling process is vital to our understanding. The substrates or targets determine their potential as well as magnitude of the impact they have on signaling pathways. In this article, we exclusively overview the various substrates of protein phosphatases in plant signaling pathways, which are a critical determinant of the outcome of various developmental and stress stimuli.
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Affiliation(s)
- Lokesh K Saini
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Malathi Bheri
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India.
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11
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Oberoi J, Guiu XA, Outwin EA, Schellenberger P, Roumeliotis TI, Choudhary JS, Pearl LH. HSP90-CDC37-PP5 forms a structural platform for kinase dephosphorylation. Nat Commun 2022; 13:7343. [PMID: 36446791 PMCID: PMC9709061 DOI: 10.1038/s41467-022-35143-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/18/2022] [Indexed: 12/02/2022] Open
Abstract
Activation of client protein kinases by the HSP90 molecular chaperone system is affected by phosphorylation at multiple sites on HSP90, the kinase-specific co-chaperone CDC37, and the kinase client itself. Removal of regulatory phosphorylation from client kinases and their release from the HSP90-CDC37 system depends on the Ser/Thr phosphatase PP5, which associates with HSP90 via its N-terminal TPR domain. Here, we present the cryoEM structure of the oncogenic protein kinase client BRAFV600E bound to HSP90-CDC37, showing how the V600E mutation favours BRAF association with HSP90-CDC37. Structures of HSP90-CDC37-BRAFV600E complexes with PP5 in autoinhibited and activated conformations, together with proteomic analysis of its phosphatase activity on BRAFV600E and CRAF, reveal how PP5 is activated by recruitment to HSP90 complexes. PP5 comprehensively dephosphorylates client proteins, removing interaction sites for regulatory partners such as 14-3-3 proteins and thus performing a 'factory reset' of the kinase prior to release.
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Affiliation(s)
- Jasmeen Oberoi
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
| | - Xavi Aran Guiu
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
| | - Emily A Outwin
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
| | - Pascale Schellenberger
- Electron Microscopy Imaging centre, School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK
| | - Theodoros I Roumeliotis
- Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Jyoti S Choudhary
- Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Laurence H Pearl
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK.
- Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK.
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12
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Kokot T, Köhn M. Emerging insights into serine/threonine-specific phosphoprotein phosphatase function and selectivity. J Cell Sci 2022; 135:277104. [DOI: 10.1242/jcs.259618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
ABSTRACT
Protein phosphorylation on serine and threonine residues is a widely distributed post-translational modification on proteins that acts to regulate their function. Phosphoprotein phosphatases (PPPs) contribute significantly to a plethora of cellular functions through the accurate dephosphorylation of phosphorylated residues. Most PPPs accomplish their purpose through the formation of complex holoenzymes composed of a catalytic subunit with various regulatory subunits. PPP holoenzymes then bind and dephosphorylate substrates in a highly specific manner. Despite the high prevalence of PPPs and their important role for cellular function, their mechanisms of action in the cell are still not well understood. Nevertheless, substantial experimental advancements in (phospho-)proteomics, structural and computational biology have contributed significantly to a better understanding of PPP biology in recent years. This Review focuses on recent approaches and provides an overview of substantial new insights into the complex mechanism of PPP holoenzyme regulation and substrate selectivity.
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Affiliation(s)
- Thomas Kokot
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
| | - Maja Köhn
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
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13
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Metal cofactor stabilization by a partner protein is a widespread strategy employed for amidase activation. Proc Natl Acad Sci U S A 2022; 119:e2201141119. [PMID: 35733252 PMCID: PMC9245657 DOI: 10.1073/pnas.2201141119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Construction and remodeling of the bacterial peptidoglycan (PG) cell wall must be carefully coordinated with cell growth and division. Central to cell wall construction are hydrolases that cleave bonds in peptidoglycan. These enzymes also represent potential new antibiotic targets. One such hydrolase, the amidase LytH in Staphylococcus aureus, acts to remove stem peptides from PG, controlling where substrates are available for insertion of new PG strands and consequently regulating cell size. When it is absent, cells grow excessively large and have division defects. For activity, LytH requires a protein partner, ActH, that consists of an intracellular domain, a large rhomboid protease domain, and three extracellular tetratricopeptide repeats (TPRs). Here, we demonstrate that the amidase-activating function of ActH is entirely contained in its extracellular TPRs. We show that ActH binding stabilizes metals in the LytH active site and that LytH metal binding in turn is needed for stable complexation with ActH. We further present a structure of a complex of the extracellular domains of LytH and ActH. Our findings suggest that metal cofactor stabilization is a general strategy used by amidase activators and that ActH houses multiple functions within a single protein.
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14
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Heat Shock-Binding Protein 21 Regulates the Innate Immune Response to Viral Infection. J Virol 2022; 96:e0000122. [DOI: 10.1128/jvi.00001-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The innate immune system is the first-line host defense against microbial pathogen invasion. The physiological functions of molecular chaperones, involving cell differentiation, migration, proliferation and inflammation, have been intensively studied.
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15
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Timmons JA, Anighoro A, Brogan RJ, Stahl J, Wahlestedt C, Farquhar DG, Taylor-King J, Volmar CH, Kraus WE, Phillips SM. A human-based multi-gene signature enables quantitative drug repurposing for metabolic disease. eLife 2022; 11:68832. [PMID: 35037854 PMCID: PMC8763401 DOI: 10.7554/elife.68832] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 11/26/2021] [Indexed: 12/22/2022] Open
Abstract
Insulin resistance (IR) contributes to the pathophysiology of diabetes, dementia, viral infection, and cardiovascular disease. Drug repurposing (DR) may identify treatments for IR; however, barriers include uncertainty whether in vitro transcriptomic assays yield quantitative pharmacological data, or how to optimise assay design to best reflect in vivo human disease. We developed a clinical-based human tissue IR signature by combining lifestyle-mediated treatment responses (>500 human adipose and muscle biopsies) with biomarkers of disease status (fasting IR from >1200 biopsies). The assay identified a chemically diverse set of >130 positively acting compounds, highly enriched in true positives, that targeted 73 proteins regulating IR pathways. Our multi-gene RNA assay score reflected the quantitative pharmacological properties of a set of epidermal growth factor receptor-related tyrosine kinase inhibitors, providing insight into drug target specificity; an observation supported by deep learning-based genome-wide predicted pharmacology. Several drugs identified are suitable for evaluation in patients, particularly those with either acute or severe chronic IR.
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Affiliation(s)
- James A Timmons
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.,Augur Precision Medicine LTD, Stirling, United Kingdom
| | | | | | - Jack Stahl
- Center for Therapeutic Innovation, Miller School of Medicine, University of Miami, Miami, United States
| | - Claes Wahlestedt
- Center for Therapeutic Innovation, Miller School of Medicine, University of Miami, Miami, United States
| | | | | | - Claude-Henry Volmar
- Center for Therapeutic Innovation, Miller School of Medicine, University of Miami, Miami, United States
| | | | - Stuart M Phillips
- Faculty of Science, Kinesiology, McMaster University, Hamilton, Canada
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16
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Loescher CM, Hobbach AJ, Linke WA. Titin (TTN): from molecule to modifications, mechanics and medical significance. Cardiovasc Res 2021; 118:2903-2918. [PMID: 34662387 PMCID: PMC9648829 DOI: 10.1093/cvr/cvab328] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/13/2021] [Indexed: 12/19/2022] Open
Abstract
The giant sarcomere protein titin is a major determinant of cardiomyocyte stiffness and contributor to cardiac strain sensing. Titin-based forces are highly regulated in health and disease, which aids in the regulation of myocardial function, including cardiac filling and output. Due to the enormous size, complexity, and malleability of the titin molecule, titin properties are also vulnerable to dysregulation, as observed in various cardiac disorders. This review provides an overview of how cardiac titin properties can be changed at a molecular level, including the role isoform diversity and post-translational modifications (acetylation, oxidation, and phosphorylation) play in regulating myocardial stiffness and contractility. We then consider how this regulation becomes unbalanced in heart disease, with an emphasis on changes in titin stiffness and protein quality control. In this context, new insights into the key pathomechanisms of human cardiomyopathy due to a truncation in the titin gene (TTN) are discussed. Along the way, we touch on the potential for titin to be therapeutically targeted to treat acquired or inherited cardiac conditions, such as HFpEF or TTN-truncation cardiomyopathy.
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Affiliation(s)
- Christine M Loescher
- Institute of Physiology II, University Hospital Münster, Robert-Koch-Str. 27B, Münster, 48149 Germany
| | - Anastasia J Hobbach
- Department of Cardiology I, Coronary, Peripheral Vascular Disease and Heart Failure, University Hospital Münster, Münster, Germany
| | - Wolfgang A Linke
- Institute of Physiology II, University Hospital Münster, Robert-Koch-Str. 27B, Münster, 48149 Germany
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17
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von Horsten S, Essen LO. Conformational Change of Tetratricopeptide Repeats Region Triggers Activation of Phytochrome-Associated Protein Phosphatase 5. FRONTIERS IN PLANT SCIENCE 2021; 12:733069. [PMID: 34721460 PMCID: PMC8551457 DOI: 10.3389/fpls.2021.733069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
Phytochrome activity is not only controlled by light but also by post-translational modifications, e. g. phosphorylation. One of the phosphatases responsible for plant phytochrome dephosphorylation and thereby increased activity is the phytochrome-associated protein phosphatase 5 (PAPP5). We show that PAPP5 recognizes phospho-site mimicking mutants of phytochrome B, when being activated by arachidonic acid (AA). Addition of AA to PAPP5 decreases the α-helical content as tracked by CD-spectroscopy. These changes correspond to conformational changes of the regulatory tetratricopeptide repeats (TPR) region as shown by mapping data from hydrogen deuterium exchange mass spectrometry onto a 3.0 Å crystal structure of PAPP5. Surprisingly, parts of the linker between the TPR and PP2A domains and of the so-called C-terminal inhibitory motif exhibit reduced deuterium uptake upon AA-binding. Molecular dynamics analyses of PAPP5 complexed to a phyB phosphopeptide show that this C-terminal motif remains associated with the TPR region in the substrate bound state, suggesting that this motif merely serves for restricting the orientations of the TPR region relative to the catalytic PP2A domain. Given the high similarity to mammalian PP5 these data from a plant ortholog show that the activation mode of these PPP-type protein phosphatases is highly conserved.
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Affiliation(s)
- Silke von Horsten
- Department of Biochemistry, Faculty of Chemistry, Philipps-University, Marburg, Germany
| | - Lars-Oliver Essen
- Department of Biochemistry, Faculty of Chemistry, Philipps-University, Marburg, Germany
- Center for Synthetic Microbiology, Philipps-University, Marburg, Germany
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18
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Muthusamy M, Kim JH, Kim SH, Park SY, Lee SI. BrPP5.2 Overexpression Confers Heat Shock Tolerance in Transgenic Brassica rapa through Inherent Chaperone Activity, Induced Glucosinolate Biosynthesis, and Differential Regulation of Abiotic Stress Response Genes. Int J Mol Sci 2021; 22:ijms22126437. [PMID: 34208567 PMCID: PMC8234546 DOI: 10.3390/ijms22126437] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/14/2021] [Accepted: 06/14/2021] [Indexed: 12/13/2022] Open
Abstract
Plant phosphoprotein phosphatases are ubiquitous and multifarious enzymes that respond to developmental requirements and stress signals through reversible dephosphorylation of target proteins. In this study, we investigated the hitherto unknown functions of Brassica rapa protein phosphatase 5.2 (BrPP5.2) by transgenic overexpression of B. rapa lines. The overexpression of BrPP5.2 in transgenic lines conferred heat shock tolerance in 65–89% of the young transgenic seedlings exposed to 46 °C for 25 min. The examination of purified recombinant BrPP5.2 at different molar ratios efficiently prevented the thermal aggregation of malate dehydrogenase at 42 °C, thus suggesting that BrPP5.2 has inherent chaperone activities. The transcriptomic dynamics of transgenic lines, as determined using RNA-seq, revealed that 997 and 1206 (FDR < 0.05, logFC ≥ 2) genes were up- and down-regulated, as compared to non-transgenic controls. Statistical enrichment analyses revealed abiotic stress response genes, including heat stress response (HSR), showed reduced expression in transgenic lines under optimal growth conditions. However, most of the HSR DEGs were upregulated under high temperature stress (37 °C/1 h) conditions. In addition, the glucosinolate biosynthesis gene expression and total glucosinolate content increased in the transgenic lines. These findings provide a new avenue related to BrPP5.2 downstream genes and their crucial metabolic and heat stress responses in plants.
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Affiliation(s)
- Muthusamy Muthusamy
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
| | - Jong Hee Kim
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
- Division of Horticultural Biotechnology, Hankyung National University, Anseong 17579, Korea
| | - Suk Hee Kim
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
| | - So Young Park
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
| | - Soo In Lee
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
- Correspondence: ; Tel.: +82-63-238-4618; Fax: +82-63-238-4604
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19
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Barik S. An Analytical Review of the Structural Features of Pentatricopeptide Repeats: Strategic Amino Acids, Repeat Arrangements and Superhelical Architecture. Int J Mol Sci 2021; 22:ijms22105407. [PMID: 34065603 PMCID: PMC8160929 DOI: 10.3390/ijms22105407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/27/2022] Open
Abstract
Tricopeptide repeats are common in natural proteins, and are exemplified by 34- and 35-residue repeats, known respectively as tetratricopeptide repeats (TPRs) and pentatricopeptide repeats (PPRs). In both classes, each repeat unit forms an antiparallel bihelical structure, so that multiple such units in a polypeptide are arranged in a parallel fashion. The primary structures of the motifs are nonidentical, but amino acids of similar properties occur in strategic positions. The focus of the present work was on PPR, but TPR, its better-studied cousin, is often included for comparison. The analyses revealed that critical amino acids, namely Gly, Pro, Ala and Trp, were placed at distinct locations in the higher order structure of PPR domains. While most TPRs occur in repeats of three, the PPRs exhibited a much greater diversity in repeat numbers, from 1 to 30 or more, separated by spacers of various sequences and lengths. Studies of PPR strings in proteins showed that the majority of PPR units are single, and that the longer tandems (i.e., without space in between) occurred in decreasing order. The multi-PPR domains also formed superhelical vortices, likely governed by interhelical angles rather than the spacers. These findings should be useful in designing and understanding the PPR domains.
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Affiliation(s)
- Sailen Barik
- EonBio, 3780 Pelham Drive, Mobile, AL 36619, USA
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20
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Neumann J, Boknik P, Kirchhefer U, Gergs U. The role of PP5 and PP2C in cardiac health and disease. Cell Signal 2021; 85:110035. [PMID: 33964402 DOI: 10.1016/j.cellsig.2021.110035] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/16/2021] [Accepted: 05/03/2021] [Indexed: 02/08/2023]
Abstract
Protein phosphatases are important, for example, as functional antagonists of β-adrenergic stimulation of the mammalian heart. While β-adrenergic stimulations increase the phosphorylation state of regulatory proteins and therefore force of contraction in the heart, these phosphorylations are reversed and thus force is reduced by the activity of protein phosphatases. In this context the role of PP5 and PP2C is starting to unravel. They do not belong to the same family of phosphatases with regard to sequence homology, many similarities with regard to location, activation by lipids and putative substrates have been worked out over the years. We also suggest which pathways for regulation of PP5 and/or PP2C described in other tissues and not yet in the heart might be useful to look for in cardiac tissue. Both phosphatases might play a role in signal transduction of sarcolemmal receptors in the heart. Expression of PP5 and PP2C can be increased by extracellular stimuli in the heart. Because PP5 is overexpressed in failing animal and human hearts, and because overexpression of PP5 or PP2C leads to cardiac hypertrophy and KO of PP5 leads to cardiac hypotrophy, one might argue for a role of PP5 and PP2C in heart failure. Because PP5 and PP2C can reduce, at least in vitro, the phosphorylation state of proteins thought to be relevant for cardiac arrhythmias, a role of these phosphatases for cardiac arrhythmias is also probable. Thus, PP5 and PP2C might be druggable targets to treat important cardiac diseases like heart failure, cardiac hypertrophy and cardiac arrhythmias.
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Affiliation(s)
- Joachim Neumann
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Magdeburger Str. 4, D-06097 Halle, Germany.
| | - Peter Boknik
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Westfälische Wilhelms-Universität, Domagkstraße 12, D-48149 Münster, Germany.
| | - Uwe Kirchhefer
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Westfälische Wilhelms-Universität, Domagkstraße 12, D-48149 Münster, Germany.
| | - Ulrich Gergs
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Magdeburger Str. 4, D-06097 Halle, Germany.
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21
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Yeo HK, Park TH, Kim HY, Jang H, Lee J, Hwang GS, Ryu SE, Park SH, Song HK, Ban HS, Yoon HJ, Lee BI. Phospholipid transfer function of PTPIP51 at mitochondria-associated ER membranes. EMBO Rep 2021; 22:e51323. [PMID: 33938112 DOI: 10.15252/embr.202051323] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 02/24/2021] [Accepted: 03/22/2021] [Indexed: 01/08/2023] Open
Abstract
In eukaryotic cells, mitochondria are closely tethered to the endoplasmic reticulum (ER) at sites called mitochondria-associated ER membranes (MAMs). Ca2+ ion and phospholipid transfer occurs at MAMs to support diverse cellular functions. Unlike those in yeast, the protein complexes involved in phospholipid transfer at MAMs in humans have not been identified. Here, we determine the crystal structure of the tetratricopeptide repeat domain of PTPIP51 (PTPIP51_TPR), a mitochondrial protein that interacts with the ER-anchored VAPB protein at MAMs. The structure of PTPIP51_TPR shows an archetypal TPR fold, and an electron density map corresponding to an unidentified lipid-like molecule probably derived from the protein expression host is found in the structure. We reveal functions of PTPIP51 in phospholipid binding/transfer, particularly of phosphatidic acid, in vitro. Depletion of PTPIP51 in cells reduces the mitochondrial cardiolipin level. Additionally, we confirm that the PTPIP51-VAPB interaction is mediated by the FFAT-like motif of PTPIP51 and the MSP domain of VAPB. Our findings suggest that PTPIP51 is a phospholipid transfer protein with a MAM-tethering function.
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Affiliation(s)
- Hyun Ku Yeo
- Research Institute, National Cancer Center, Goyang-si, Korea
| | - Tae Hyun Park
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Bioengineering, Hanyang University, Seoul, Korea
| | - Hee Yeon Kim
- Research Institute, National Cancer Center, Goyang-si, Korea
| | - Hyonchol Jang
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang-si, Korea
| | - Jueun Lee
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea
| | - Geum-Sook Hwang
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea.,Department of Chemistry and Nano Science, Ewha Womans University, Seoul, Korea
| | - Seong Eon Ryu
- Department of Bioengineering, Hanyang University, Seoul, Korea
| | - Si Hoon Park
- Department of Life Sciences, Korea University, Seoul, Korea
| | - Hyun Kyu Song
- Department of Life Sciences, Korea University, Seoul, Korea
| | - Hyun Seung Ban
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | - Hye-Jin Yoon
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, Korea
| | - Byung Il Lee
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang-si, Korea
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22
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Xiao Y, Nie L, Chen H, He M, Liang Q, Nie H, Chen W, Huang Q. The two-component system TarR-TarS is regulated by c-di-GMP/FleQ and FliA and modulates antibiotic susceptibility in Pseudomonas putida. Environ Microbiol 2021; 23:5239-5257. [PMID: 33938113 DOI: 10.1111/1462-2920.15555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 04/19/2021] [Accepted: 04/30/2021] [Indexed: 11/29/2022]
Abstract
Two-component systems (TCSs) are predominant means by which bacteria sense and respond to environment signals. Genome of Pseudomonas putida contains dozens of putative TCS-encoding genes, but phenotypical-genotypical correlation and transcriptional regulation of these genes are largely unknown. Herein, we characterized function and transcriptional regulation of a conserved P. putida TCS, named TarR-TarS. TarS (PP_0769) encodes a potential histidine kinase, and tarR (PP_0768) encodes a potential response regulator. Protein-protein interaction assay and phosphorylation assay confirmed that TarR-TarS was a functional TCS. Growth assay under antibiotics revealed that TarR-TarS positively regulated bacterial resistance to multiple antibiotics. Pull-down assay revealed that TarR directly interacted with PP_0800 (a hypothetical protein) and GroEL (the chaperonin). GroEL played a positive role in antibiotic resistance, while PP_0800 seemed to have no effect on antibiotic resistance. The regulator FleQ indirectly activated tarR-tarS transcription. However, the second messenger c-di-GMP antagonized FleQ activation to inhibit tarR-tarS transcription. The sigma factor FliA directly activated tarR-tarS transcription via a consensus motif. These findings reveal function and transcriptional regulation of TarR-TarS, and enrich knowledge regarding the relationship between c-di-GMP and antibiotic susceptibility in P. putida.
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Affiliation(s)
- Yujie Xiao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Liang Nie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Haozhe Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Meina He
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qingyuan Liang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hailing Nie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
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23
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Mazaira GI, Echeverría PC, Ciucci SM, Monte M, Gallo LI, Erlejman AG, Galigniana MD. Differential regulation of the glucocorticoid receptor nucleocytoplasmic shuttling by TPR-domain proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119000. [PMID: 33675851 DOI: 10.1016/j.bbamcr.2021.119000] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 02/21/2021] [Accepted: 02/25/2021] [Indexed: 12/14/2022]
Abstract
A dimer of the heat-shock protein of 90-kDa (Hsp90) represents the critical core of the chaperone complex associated to the glucocorticoid receptor (GR) oligomer. The C-terminal end of the Hsp90 dimer shapes a functional acceptor site for co-chaperones carrying tetratricopeptide repeat (TPR) domains, where they bind in a mutually exclusive and competitive manner. They impact on the biological properties of the GR•Hsp90 complex and are major players of the GR transport machinery. Recently, we showed that the overexpression of a chimeric TPR peptide influences the subcellular distribution of GR. In this study, the functional role of endogenous proteins carrying TPR or TPR-like sequences on GR subcellular distribution was characterized. It is demonstrated that, contrarily to the positive influence of FKBP52 on GR nuclear accumulation, FKBP51 and 14-3-3 impaired this property. While SGT1α showed no significant effect, the overexpression of the Ser/Thr phosphatase PP5 resulted in a nearly equal nuclear-cytoplasmic redistribution of GR rather than its typical cytoplasmic localization in the absence of steroid. This observation led to analyse the influence of the phosphorylation status of GR, which resulted not linked to its nucleo-cytoplasmic shuttling mechanism. Nonetheless, it was evidenced that both PP5 and FKBP52 are related to the anchorage of the GR to nucleoskeleton structures. The influence of these TPR domain proteins on the steroid-dependent transcriptional activity of GR was also characterized. It is postulated that the pleiotropic actions of the GR in different cell types may be the consequence of the relative abundance of different TPR-domain interacting co-chaperones.
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Affiliation(s)
- Gisela I Mazaira
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Pablo C Echeverría
- Instituto de Biología y Medicina Experimental (IBYME)-CONICET, Buenos Aires 1428, Argentina
| | - Sol M Ciucci
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Martin Monte
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Luciana I Gallo
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE)-CONICET, Buenos Aires 1428, Argentina
| | - Alejandra G Erlejman
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Mario D Galigniana
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina; Instituto de Biología y Medicina Experimental (IBYME)-CONICET, Buenos Aires 1428, Argentina.
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24
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Struk S, De Cuyper C, Jacobs A, Braem L, Walton A, De Keyser A, Depuydt S, Vu LD, De Smet I, Boyer FD, Eeckhout D, Persiau G, Gevaert K, De Jaeger G, Goormachtig S. Unraveling the MAX2 Protein Network in Arabidopsis thaliana: Identification of the Protein Phosphatase PAPP5 as a Novel MAX2 Interactor. Mol Cell Proteomics 2021; 20:100040. [PMID: 33372050 PMCID: PMC7950214 DOI: 10.1074/mcp.ra119.001766] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/18/2020] [Accepted: 12/28/2020] [Indexed: 12/12/2022] Open
Abstract
The F-box protein MORE AXILLARY GROWTH 2 (MAX2) is a central component in the signaling cascade of strigolactones (SLs) as well as of the smoke-derived karrikins (KARs) and the so far unknown endogenous KAI2 ligand (KL). The two groups of molecules are involved in overlapping and unique developmental processes, and signal-specific outcomes are attributed to perception by the paralogous α/β-hydrolases DWARF14 (D14) for SL and KARRIKIN INSENSITIVE 2/HYPOSENSITIVE TO LIGHT (KAI2/HTL) for KAR/KL. In addition, depending on which receptor is activated, specific members of the SUPPRESSOR OF MAX2 1 (SMAX1)-LIKE (SMXL) family control KAR/KL and SL responses. As proteins that function in the same signal transduction pathway often occur in large protein complexes, we aimed at discovering new players of the MAX2, D14, and KAI2 protein network by tandem affinity purification in Arabidopsis cell cultures. When using MAX2 as a bait, various proteins were copurified, among which were general components of the Skp1-Cullin-F-box complex and members of the CONSTITUTIVE PHOTOMORPHOGENIC 9 signalosome. Here, we report the identification of a novel interactor of MAX2, a type 5 serine/threonine protein phosphatase, designated PHYTOCHROME-ASSOCIATED PROTEIN PHOSPHATASE 5 (PAPP5). Quantitative affinity purification pointed at PAPP5 as being more present in KAI2 rather than in D14 protein complexes. In agreement, mutant analysis suggests that PAPP5 modulates KAR/KL-dependent seed germination under suboptimal conditions and seedling development. In addition, a phosphopeptide enrichment experiment revealed that PAPP5 might dephosphorylate MAX2 in vivo independently of the synthetic SL analog, rac-GR24. Together, by analyzing the protein complexes to which MAX2, D14, and KAI2 belong, we revealed a new MAX2 interactor, PAPP5, that might act through dephosphorylation of MAX2 to control mainly KAR/KL-related phenotypes and, hence, provide another link with the light pathway.
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Affiliation(s)
- Sylwia Struk
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Carolien De Cuyper
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Anse Jacobs
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Lukas Braem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Alan Walton
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Annick De Keyser
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Stephen Depuydt
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Lam Dai Vu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Ive De Smet
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - François-Didier Boyer
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), AgroParisTech, Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Versailles, France; Institut de Chimie des Substances Naturelles, CNRS Unité Propre de Recherche 2301, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Dominique Eeckhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Geert Persiau
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Kris Gevaert
- Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium.
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25
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Karkache IY, Damodaran JR, Molstad DHH, Bradley EW. Serine/threonine phosphatases in osteoclastogenesis and bone resorption. Gene 2020; 771:145362. [PMID: 33338510 DOI: 10.1016/j.gene.2020.145362] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 11/24/2020] [Accepted: 12/08/2020] [Indexed: 12/27/2022]
Abstract
Maintenance of optimal bone mass is controlled through the concerted functions of several cell types, including bone resorbing osteoclasts. Osteoclasts function to remove calcified tissue during developmental bone modeling, and degrade bone at sites of damage during bone remodeling. Changes to bone homeostasis can arise with alterations in osteoclastogenesis and/or catabolic activity that are not offset by anabolic activity; thus, factors that regulate osteoclastogenesis and bone resorption are of interest to further our understanding of basic bone biology, and as potential targets for therapeutic intervention. Several key cytokines, including RANKL and M-CSF, as well as co-stimulatory factors elicit kinase signaling cascades that promote osteoclastogenesis. These kinase cascades are offset by the action of protein phosphatases, including members of the serine/threonine phosphatase family. Here we review the functions of serine/threonine phosphatases and their control of osteoclast differentiation and function, while highlighting deficiencies in our understanding of this understudied class of proteins within the field.
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Affiliation(s)
- Ismael Y Karkache
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN 55455, United States
| | - Jeyaram R Damodaran
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN 55455, United States
| | - David H H Molstad
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN 55455, United States
| | - Elizabeth W Bradley
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN 55455, United States; Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, United States.
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26
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Bertucci EM, Mason MW, Camus AC, Rhodes OE, Parrott BB. Chronic low dose irradiation alters hepatic transcriptional profiles, but not global DNA methylation in medaka (Oryzias latipes). THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 729:138680. [PMID: 32361431 DOI: 10.1016/j.scitotenv.2020.138680] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/26/2020] [Accepted: 04/11/2020] [Indexed: 06/11/2023]
Abstract
Ionizing radiation (IR) resulting from both natural and anthropogenic sources is ubiquitous throughout the environment. Historically, studies on the biological impacts of radiation primarily focused on responses to acute doses of radiation, with little advancement in our understanding of environmentally relevant exposures. Epigenetic mechanisms are capable of mediating organismal responses to environmental stressors and DNA methylation plays important roles in gene regulation and promoting chromosomal stability. Here, we assess broad-scale transcriptional and epigenetic variation resulting from chronic exposure to low doses of ionizing radiation (LDIR; 5.78, 53.76, or 520.23 mGy/day) using Japanese medaka fish (Oryzias latipes) in a replicated mesocosm design. We observed significant changes to the hepatic transcriptome induced by a 3-month chronic exposure to IR, whereas global DNA methylation appeared largely unaffected. Our findings reveal a set of genes, including those involved in immune function, responding to environmentally relevant IR exposures, which do not appear to be mediated by a systemic global shift in DNA methylation.
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Affiliation(s)
- Emily M Bertucci
- Odum School of Ecology, University of Georgia, 140 E. Green St., Athens 30602, GA, USA; Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E, Aiken 29802, SC, USA.
| | - Marilyn W Mason
- Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E, Aiken 29802, SC, USA.
| | - Alvin C Camus
- College of Veterinary Medicine Department of Pathology, University of Georgia, 501 D.W. Brooks Drive, Athens 30602, GA, USA.
| | - Olin E Rhodes
- Odum School of Ecology, University of Georgia, 140 E. Green St., Athens 30602, GA, USA; Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E, Aiken 29802, SC, USA.
| | - Benjamin B Parrott
- Odum School of Ecology, University of Georgia, 140 E. Green St., Athens 30602, GA, USA; Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E, Aiken 29802, SC, USA.
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27
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Bheri M, Mahiwal S, Sanyal SK, Pandey GK. Plant protein phosphatases: What do we know about their mechanism of action? FEBS J 2020; 288:756-785. [PMID: 32542989 DOI: 10.1111/febs.15454] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/27/2020] [Accepted: 06/09/2020] [Indexed: 12/30/2022]
Abstract
Protein phosphorylation is a major reversible post-translational modification. Protein phosphatases function as 'critical regulators' in signaling networks through dephosphorylation of proteins, which have been phosphorylated by protein kinases. A large understanding of their working has been sourced from animal systems rather than the plant or the prokaryotic systems. The eukaryotic protein phosphatases include phosphoprotein phosphatases (PPP), metallo-dependent protein phosphatases (PPM), protein tyrosine (Tyr) phosphatases (PTP), and aspartate (Asp)-dependent phosphatases. The PPP and PPM families are serine(Ser)/threonine(Thr)-specific phosphatases (STPs), while PTP family is Tyr specific. Dual-specificity phosphatases (DsPTPs/DSPs) dephosphorylate Ser, Thr, and Tyr residues. PTPs lack sequence homology with STPs, indicating a difference in catalytic mechanisms, while the PPP and PPM families share a similar structural fold indicating a common catalytic mechanism. The catalytic cysteine (Cys) residue in the conserved HCX5 R active site motif of the PTPs acts as a nucleophile during hydrolysis. The PPP members require metal ions, which coordinate the phosphate group of the substrate, followed by a nucleophilic attack by a water molecule and hydrolysis. The variable holoenzyme assembly of protein phosphatase(s) and the overlap with other post-translational modifications like acetylation and ubiquitination add to their complexity. Though their functional characterization is extensively reported in plants, the mechanistic nature of their action is still being explored by researchers. In this review, we exclusively overview the plant protein phosphatases with an emphasis on their mechanistic action as well as structural characteristics.
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Affiliation(s)
- Malathi Bheri
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Swati Mahiwal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Sibaji K Sanyal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
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28
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Mazaira GI, Echeverria PC, Galigniana MD. Nucleocytoplasmic shuttling of the glucocorticoid receptor is influenced by tetratricopeptide repeat-containing proteins. J Cell Sci 2020; 133:jcs238873. [PMID: 32467326 DOI: 10.1242/jcs.238873] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 04/07/2020] [Indexed: 08/31/2023] Open
Abstract
It has been demonstrated that tetratricopeptide-repeat (TPR) domain proteins regulate the subcellular localization of glucocorticoid receptor (GR). This study analyses the influence of the TPR domain of high molecular weight immunophilins in the retrograde transport and nuclear retention of GR. Overexpression of the TPR peptide prevented efficient nuclear accumulation of the GR by disrupting the formation of complexes with the dynein-associated immunophilin FKBP52 (also known as FKBP4), the adaptor transporter importin-β1 (KPNB1), the nuclear pore-associated glycoprotein Nup62 and nuclear matrix-associated structures. We also show that nuclear import of GR was impaired, whereas GR nuclear export was enhanced. Interestingly, the CRM1 (exportin-1) inhibitor leptomycin-B abolished the effects of TPR peptide overexpression, although the drug did not inhibit GR nuclear export itself. This indicates the existence of a TPR-domain-dependent mechanism for the export of nuclear proteins. The expression balance of those TPR domain proteins bound to the GR-Hsp90 complex may determine the subcellular localization and nucleocytoplasmic properties of the receptor, and thereby its pleiotropic biological properties in different tissues and cell types.
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Affiliation(s)
- Gisela I Mazaira
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Pablo C Echeverria
- Département de Biologie Cellulaire, Université de Genève, Sciences III, Genève 1211, Switzerland
| | - Mario D Galigniana
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
- Instituto de Biología y Medicina Experimental (IBYME)-CONICET, Buenos Aires 1428, Argentina
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29
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Sager RA, Dushukyan N, Woodford M, Mollapour M. Structure and function of the co-chaperone protein phosphatase 5 in cancer. Cell Stress Chaperones 2020; 25:383-394. [PMID: 32239474 PMCID: PMC7193036 DOI: 10.1007/s12192-020-01091-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/04/2020] [Accepted: 03/12/2020] [Indexed: 12/12/2022] Open
Abstract
Protein phosphatase 5 (PP5) is a serine/threonine protein phosphatase that regulates many cellular functions including steroid hormone signaling, stress response, proliferation, apoptosis, and DNA repair. PP5 is also a co-chaperone of the heat shock protein 90 molecular chaperone machinery that assists in regulation of cellular signaling pathways essential for cell survival and growth. PP5 plays a significant role in survival and propagation of multiple cancers, which makes it a promising target for cancer therapy. Though there are several naturally occurring PP5 inhibitors, none is specific for PP5. Here, we review the roles of PP5 in cancer progression and survival and discuss the unique features of the PP5 structure that differentiate it from other phosphoprotein phosphatase (PPP) family members and make it an attractive therapeutic target.
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Affiliation(s)
- Rebecca A Sager
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- College of Medicine, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Natela Dushukyan
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Mark Woodford
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Mehdi Mollapour
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA.
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA.
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, 13210, USA.
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30
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Biebl MM, Buchner J. Structure, Function, and Regulation of the Hsp90 Machinery. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a034017. [PMID: 30745292 DOI: 10.1101/cshperspect.a034017] [Citation(s) in RCA: 166] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Heat shock protein 90 (Hsp90) is a molecular chaperone involved in the maturation of a plethora of substrates ("clients"), including protein kinases, transcription factors, and E3 ubiquitin ligases, positioning Hsp90 as a central regulator of cellular proteostasis. Hsp90 undergoes large conformational changes during its ATPase cycle. The processing of clients by cytosolic Hsp90 is assisted by a cohort of cochaperones that affect client recruitment, Hsp90 ATPase function or conformational rearrangements in Hsp90. Because of the importance of Hsp90 in regulating central cellular pathways, strategies for the pharmacological inhibition of the Hsp90 machinery in diseases such as cancer and neurodegeneration are being developed. In this review, we summarize recent structural and mechanistic progress in defining the function of organelle-specific and cytosolic Hsp90, including the impact of individual cochaperones on the maturation of specific clients and complexes with clients as well as ways of exploiting Hsp90 as a drug target.
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Affiliation(s)
- Maximilian M Biebl
- Center for Integrated Protein Science, Department of Chemistry, Technische Universität München, D-85748 Garching, Germany
| | - Johannes Buchner
- Center for Integrated Protein Science, Department of Chemistry, Technische Universität München, D-85748 Garching, Germany
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31
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Amorim-Silva V, García-Moreno Á, Castillo AG, Lakhssassi N, Esteban Del Valle A, Pérez-Sancho J, Li Y, Posé D, Pérez-Rodriguez J, Lin J, Valpuesta V, Borsani O, Zipfel C, Macho AP, Botella MA. TTL Proteins Scaffold Brassinosteroid Signaling Components at the Plasma Membrane to Optimize Signal Transduction in Arabidopsis. THE PLANT CELL 2019; 31:1807-1828. [PMID: 31189737 PMCID: PMC6713313 DOI: 10.1105/tpc.19.00150] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/07/2019] [Accepted: 05/31/2019] [Indexed: 05/20/2023]
Abstract
Brassinosteroids (BRs) form a group of steroidal hormones essential for plant growth, development, and stress responses. BRs are perceived extracellularly by plasma membrane receptor-like kinases that activate an interconnected signal transduction cascade, leading to the transcriptional regulation of BR-responsive genes. TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) genes are specific for land plants, and their encoded proteins are defined by the presence of protein-protein interaction motives, that is, an intrinsic disordered region at the N terminus, six tetratricopeptide repeat domains, and a C terminus with homology to thioredoxins. TTL proteins thus likely mediate the assembly of multiprotein complexes. Phenotypic, molecular, and genetic analyses show that TTL proteins are positive regulators of BR signaling in Arabidopsis (Arabidopsis thaliana). TTL3 directly interacts with a constitutively active BRASSINOSTEROID INSENSITIVE1 (BRI1) receptor kinase, BRI1-SUPPRESSOR1 phosphatase, and the BRASSINAZOLE RESISTANT1 transcription factor and associates with BR-SIGNALING KINASE1, BRASSINOSTEROID INSENSITIVE2 kinases, but not with BRI1-ASSOCIATED KINASE1. A functional TTL3-green fluorescent protein (GFP) shows dual cytoplasmic plasma membrane localization. Depleting the endogenous BR content reduces plasma membrane localization of TTL3-GFP, while increasing BR content causes its plasma membrane relocalization, where it strengthens the association of BR signaling components. Our results reveal that TTL proteins promote BR responses and suggest that TTL proteins may function as scaffold proteins by bringing together cytoplasmic and plasma membrane BR signaling components.
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Affiliation(s)
- Vítor Amorim-Silva
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Álvaro García-Moreno
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Araceli G Castillo
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Naoufal Lakhssassi
- Department of Plant, Soil and Agricultural Systems, Southern Illinois University, Carbondale, Illinois 62901
| | - Alicia Esteban Del Valle
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Jessica Pérez-Sancho
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Yansha Li
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
| | - David Posé
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Josefa Pérez-Rodriguez
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Jinxing Lin
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Victoriano Valpuesta
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Omar Borsani
- Departamento de Biología Vegetal, Laboratorio de Bioquímica, Facultad de Agronomía Universidad de la República, Montevideo, Uruguay
| | - Cyril Zipfel
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
- Institute of Plant and Microbial Biology and Zurich-Basel Plant Science Center, University of Zurich, CH-8008 Zurich, Switzerland
| | - Alberto P Macho
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai, China
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | - Miguel A Botella
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, 29071 Málaga, Spain
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32
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Wang L, Yan F. Exploring the role of active site Mn2+ ions in the binding of protein phosphatase 5 with its substrate using molecular dynamics simulations. Biochem Biophys Res Commun 2019; 511:612-618. [DOI: 10.1016/j.bbrc.2019.02.113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 02/21/2019] [Indexed: 12/14/2022]
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33
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Perez-Riba A, Itzhaki LS. The tetratricopeptide-repeat motif is a versatile platform that enables diverse modes of molecular recognition. Curr Opin Struct Biol 2019; 54:43-49. [PMID: 30708253 DOI: 10.1016/j.sbi.2018.12.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/09/2018] [Accepted: 12/12/2018] [Indexed: 01/05/2023]
Abstract
Tetratricopeptide repeat (TPR) domains and TPR-like domains are widespread across nature. They are involved in varied cellular processes and have been traditionally associated with binding to short linear peptide motifs. However, examples of a much more diverse range of molecular recognition modes are increasing year by year. The Protein Data Bank has an ever-expanding collection of TPR proteins in complex with a myriad of different partners, ranging from short linear peptide motifs to large globular protein domains. In this review, we explore these varied binding modes. Additionally, we hope to highlight an emerging property of this simple, malleable fold-the potential for programmable complexity that can be achieved by acting as a scaffold for multiple binding partners.
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Affiliation(s)
- Albert Perez-Riba
- Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada.
| | - Laura S Itzhaki
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK.
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34
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Abstract
The FK506-binding protein 51 (FKBP51) has emerged as a key regulator of endocrine stress responses in mammals and as a potential therapeutic target for stress-related disorders (depression, post-traumatic stress disorder), metabolic disorders (obesity and diabetes) and chronic pain. Recently, FKBP51 has been implicated in several cellular pathways and numerous interacting protein partners have been reported. However, no consensus on the underlying molecular mechanisms has yet emerged. Here, we review the protein interaction partners reported for FKBP51, the proposed pathways involved, their relevance to FKBP51’s physiological function(s), the interplay with other FKBPs, and implications for the development of FKBP51-directed drugs.
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Swingle MR, Honkanen RE. Inhibitors of Serine/Threonine Protein Phosphatases: Biochemical and Structural Studies Provide Insight for Further Development. Curr Med Chem 2019; 26:2634-2660. [PMID: 29737249 PMCID: PMC10013172 DOI: 10.2174/0929867325666180508095242] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/05/2018] [Accepted: 03/29/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND The reversible phosphorylation of proteins regulates many key functions in eukaryotic cells. Phosphorylation is catalyzed by protein kinases, with the majority of phosphorylation occurring on side chains of serine and threonine residues. The phosphomonoesters generated by protein kinases are hydrolyzed by protein phosphatases. In the absence of a phosphatase, the half-time for the hydrolysis of alkyl phosphate dianions at 25º C is over 1 trillion years; knon ~2 x 10-20 sec-1. Therefore, ser/thr phosphatases are critical for processes controlled by reversible phosphorylation. METHODS This review is based on the literature searched in available databases. We compare the catalytic mechanism of PPP-family phosphatases (PPPases) and the interactions of inhibitors that target these enzymes. RESULTS PPPases are metal-dependent hydrolases that enhance the rate of hydrolysis ([kcat/kM]/knon ) by a factor of ~1021, placing them among the most powerful known catalysts on earth. Biochemical and structural studies indicate that the remarkable catalytic proficiencies of PPPases are achieved by 10 conserved amino acids, DXH(X)~26DXXDR(X)~20- 26NH(X)~50H(X)~25-45R(X)~30-40H. Six act as metal-coordinating residues. Four position and orient the substrate phosphate. Together, two metal ions and the 10 catalytic residues position the phosphoryl group and an activated bridging water/hydroxide nucleophile for an inline attack upon the substrate phosphorous atom. The PPPases are conserved among species, and many structurally diverse natural toxins co-evolved to target these enzymes. CONCLUSION Although the catalytic site is conserved, opportunities for the development of selective inhibitors of this important group of metalloenzymes exist.
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Affiliation(s)
- Mark R Swingle
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile AL 36688, United States
| | - Richard E Honkanen
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile AL 36688, United States
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Hu MH, Huang TT, Chao TI, Chen LJ, Chen YL, Tsai MH, Liu CY, Kao JH, Chen KF. Serine/threonine protein phosphatase 5 is a potential therapeutic target in cholangiocarcinoma. Liver Int 2018; 38:2248-2259. [PMID: 29797403 DOI: 10.1111/liv.13887] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/20/2018] [Indexed: 02/13/2023]
Abstract
BACKGROUND & AIMS Few molecules are currently verified to be actionable drug targets in cholangiocarcinoma (CCA). Serine/threonine protein phosphatase 5 (PP5) dysregulation is related to several malignancies. However, the role of PP5 in CCA is poorly defined. METHODS Colony and tumorsphere formation assays were conducted to establish the role of PP5 in CCA tumorigenesis. Cantharidin (CTD) and norcantharidin (NCTD), both potent PP5 inhibitors, were used in in vitro and in vivo experiments to validate the potential therapeutic role of PP5. RESULTS Increased cell growth, colony formation and tumorsphere formation were observed in PP5-overexpressing CCA cells, whereas PP5 knockdown by shRNA decreased cell growth and colony formation. Tumours from HuCCT1 xenograft-bearing mice treated with PP5-shRNA showed decreased growth and increased AMP-activated protein kinase (AMPK) phosphorylation. Furthermore, CTD treatment decreased cell viability, reduced PP5 activity and enhanced AMPK phosphorylation in CCA cell lines. Overexpressing PP5 or enhancing PP5 activity suppressed AMPK phosphorylation and decreased CTD-induced cell death. Suppressing p-AMPK with siRNA or inhibitors also decreased CTD-induced cell death, suggesting a pivotal role for PP5-AMPK cascades in CCA. Immunoprecipitation revealed that PP5 interacted with AMPK. Importantly, treatment of HuCCT1 xenograft-bearing mice with NCTD, a CTD analogue with a lower systemic toxicity in vivo, suppressed PP5 activity, increased p-AMPK and reduced tumour volume. CONCLUSIONS Protein phosphatase 5 negatively regulates AMPK phosphorylation and contributes to CCA aggressiveness; thus, PP5 may be a potential therapeutic target in CCA.
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Affiliation(s)
- Ming-Hung Hu
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Division of Hematology and Oncology, Department of Medicine, Cardinal Tien Hospital, New Taipei City, Taiwan.,School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Tzu-Ting Huang
- Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei City, Taiwan
| | - Tzu-I Chao
- Transplant Medicine & Surgery Research Centre, Changhua Christian Hospital, Changhua, Taiwan
| | - Li-Ju Chen
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Yen-Lin Chen
- Department of Pathology, Cardinal Tien Hospital, New Taipei City, Taiwan
| | - Ming-Hsien Tsai
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Chun-Yu Liu
- Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei City, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Transfusion Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jia-Horng Kao
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Kuen-Feng Chen
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan.,National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan
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Norris-Mullins B, Krivda JS, Smith KL, Ferrell MJ, Morales MA. Leishmania phosphatase PP5 is a regulator of HSP83 phosphorylation and essential for parasite pathogenicity. Parasitol Res 2018; 117:2971-2985. [PMID: 29982859 DOI: 10.1007/s00436-018-5994-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 06/28/2018] [Indexed: 01/21/2023]
Abstract
Leishmania parasites are responsible for important neglected diseases in humans and animals, ranging from self-healing cutaneous lesions to fatal visceral manifestations. During the infectious cycle, Leishmania differentiates from the extracellular flagellated promastigote to the intracellular pathogenic amastigote. Parasite differentiation is triggered by changes in environmental cues, mainly pH and temperature. In general, extracellular signals are translated into stage-specific gene expression by a cascade of reversible protein phosphorylation regulated by protein kinases and phosphatases. Though protein kinases have been actively studied as potential anti-parasitic drug targets, our understanding of the biology of protein phosphatases in Leishmania is poor. We have previously reported the principal analysis of a novel protein phosphatase 5 (PP5) in Leishmania species. Here, we assessed the role of PP5 in parasite pathogenicity, where we uncovered, using transgenic PP5 over-expressing and PP5 null-mutant parasites, its importance in metacyclogeneisis, maintaining HSP83 phosphorylation homeostasis and virulence. All together, our results indicate the importance of PP5 in regulating parasite stress and adaptation during differentiation, making this protein an attractive potential target for therapeutic intervention.
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Affiliation(s)
- Brianna Norris-Mullins
- Eck Institute for Global Health, Department of Biological Sciences, 278 Galvin Life Science, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Joseph S Krivda
- Eck Institute for Global Health, Department of Biological Sciences, 278 Galvin Life Science, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Kathryn L Smith
- Eck Institute for Global Health, Department of Biological Sciences, 278 Galvin Life Science, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Micah J Ferrell
- Eck Institute for Global Health, Department of Biological Sciences, 278 Galvin Life Science, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Miguel A Morales
- Eck Institute for Global Health, Department of Biological Sciences, 278 Galvin Life Science, University of Notre Dame, Notre Dame, IN, 46556, USA.
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Dushukyan N, Dunn DM, Sager RA, Woodford MR, Loiselle DR, Daneshvar M, Baker-Williams AJ, Chisholm JD, Truman AW, Vaughan CK, Haystead TA, Bratslavsky G, Bourboulia D, Mollapour M. Phosphorylation and Ubiquitination Regulate Protein Phosphatase 5 Activity and Its Prosurvival Role in Kidney Cancer. Cell Rep 2018; 21:1883-1895. [PMID: 29141220 DOI: 10.1016/j.celrep.2017.10.074] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/28/2017] [Accepted: 10/19/2017] [Indexed: 12/13/2022] Open
Abstract
The serine/threonine protein phosphatase 5 (PP5) regulates multiple cellular signaling networks. A number of cellular factors, including heat shock protein 90 (Hsp90), promote the activation of PP5. However, it is unclear whether post-translational modifications also influence PP5 phosphatase activity. Here, we show an "on/off switch" mechanism for PP5 regulation. The casein kinase 1δ (CK1δ) phosphorylates T362 in the catalytic domain of PP5, which activates and enhances phosphatase activity independent of Hsp90. Overexpression of the phosphomimetic T362E-PP5 mutant hyper-dephosphorylates substrates such as the co-chaperone Cdc37 and glucocorticoid receptor in cells. Our proteomic approach revealed that the tumor suppressor von Hippel-Lindau protein (VHL) interacts with and ubiquitinates K185/K199-PP5 for proteasomal degradation in a hypoxia- and prolyl-hydroxylation-independent manner. Finally, VHL-deficient clear cell renal cell carcinoma (ccRCC) cell lines and patient tumors exhibit elevated PP5 levels. Downregulation of PP5 causes ccRCC cells to undergo apoptosis, suggesting a prosurvival role for PP5 in kidney cancer.
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Affiliation(s)
- Natela Dushukyan
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| | - Diana M Dunn
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| | - Rebecca A Sager
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| | - Mark R Woodford
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| | - David R Loiselle
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael Daneshvar
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| | - Alexander J Baker-Williams
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| | - John D Chisholm
- Department of Chemistry, Syracuse University, 1-014 Center for Science and Technology, Syracuse, NY 13244, USA
| | - Andrew W Truman
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Cara K Vaughan
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, Biological Sciences, Malet Street, London WC1E 7HX, UK
| | - Timothy A Haystead
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Gennady Bratslavsky
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| | - Dimitra Bourboulia
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| | - Mehdi Mollapour
- Department of Urology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA.
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Wang K, He J, Zhao Y, Wu T, Zhou X, Ding Y, Kong L, Wang X, Wang Y, Li J, Song CP, Wang B, Yang S, Zhu JK, Gong Z. EAR1 Negatively Regulates ABA Signaling by Enhancing 2C Protein Phosphatase Activity. THE PLANT CELL 2018; 30:815-834. [PMID: 29618630 PMCID: PMC5969277 DOI: 10.1105/tpc.17.00875] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/08/2018] [Accepted: 04/02/2018] [Indexed: 05/20/2023]
Abstract
The reversible phosphorylation of proteins by kinases and phosphatases is an antagonistic process that modulates many cellular functions. Protein phosphatases are usually negatively regulated by inhibitor proteins. During abscisic acid (ABA) signaling, these inhibitor proteins comprise PYR1/PYL/RCAR ABA receptors, which inhibit the core negative regulators, the clade A type 2C protein phosphatases (PP2Cs). However, it is not known whether these PP2Cs are positively regulated by other proteins. Here, we identified an Arabidopsis thaliana ear1 (enhancer of aba co-receptor1) mutant that exhibits pleiotropic ABA-hypersensitive phenotypes. EAR1 encodes an uncharacterized protein that is conserved in both monocots and dicots. EAR1 interacts with the N-terminal inhibition domains of all six PP2Cs, ABA INSENSITIVE1 (ABI1), ABI2, HYPERSENSITIVE TO ABA1 (HAB1), HAB2, ABA-HYPERSENSITIVE GERMINATION1 (AHG1), and AHG3, during ABA signaling and enhances the activity of PP2Cs both in vitro and in vivo. ABA treatment caused EAR1 to accumulate in the nucleus. These results indicate that EAR1 is a negative regulator of ABA signaling that enhances the activity of PP2Cs by interacting with and releasing the N-terminal autoinhibition of these proteins.
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Affiliation(s)
- Kai Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Junna He
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Yang Zhao
- China Shanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907
| | - Ting Wu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiaofeng Zhou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Yanglin Ding
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Lingyao Kong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiaoji Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yu Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jigang Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Chun-Peng Song
- Collaborative Innovation Center of Crop Stress Biology, Henan Province, Institute of Plant Stress Biology, Henan University, Kaifeng 475001, China
| | - Baoshan Wang
- Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Ji'nan 250014, China
| | - Shuhua Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jian-Kang Zhu
- China Shanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907
| | - Zhizhong Gong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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40
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Zhu J, Ji Y, Yu Y, Jin Y, Zhang X, Zhou J, Chen Y. Knockdown of serine/threonine protein phosphatase 5 enhances gemcitabine sensitivity by promoting apoptosis in pancreatic cancer cells in vitro. Oncol Lett 2018; 15:8761-8769. [PMID: 29805615 DOI: 10.3892/ol.2018.8363] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/22/2017] [Indexed: 12/28/2022] Open
Abstract
The targeting protein of serine/threonine protein phosphatase 5 (PPP5C) has been reported to be present in various malignancies. However, its functional role in pancreatic cancer (PC) remains unknown. In the present study, the function of PPP5C in PC cells treated with the first-line drug gemcitabine (GEM) was investigated. Short hairpin (sh)RNA targeting PPP5C was constructed to knockdown PPP5C in PANC-1 cells. Cell cycle and apoptosis analyses were performed in order to investigate the mechanisms underlying the effects induced by PPP5C silencing combined with GEM treatment. Western blot analysis was applied to detect the expression of certain key regulators of cell apoptosis in PANC-1 cells treated with GEM. shRNA against PPP5C effectively suppressed the proliferation of PANC-1 cells treated with GEM. Additionally, cell cycle analysis indicated that PPP5C knockdown resulted in a higher number of PANC-1 cells treated with GEM in G0/G1 phase arrest. Knockdown of PPP5C increased the expression of associated apoptotic markers, including cleaved caspase 3, poly (ADP-ribose) polymerase and phosphorylated (p)-p53. In addition, the combination of treatment with GEM and PPP5C silencing significantly increased the apoptosis of PANC-1 cells by affecting the expression levels of p-c-Jun N-terminal kinases and p-p38. The present study suggests that PPP5C may be a potential target for the treatment of PC and that it may enhance the gemcitabine sensitivity of PC cells.
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Affiliation(s)
- Jinhui Zhu
- Department of General Surgery and Laparoscopic Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Yun Ji
- Department of General Surgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Yuanquan Yu
- Department of General Surgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Yun Jin
- Department of General Surgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Xiaoxiao Zhang
- Department of General Surgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Jiale Zhou
- Department of General Surgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Yan Chen
- Department of General Surgery and Laparoscopic Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
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Chen C, Yan T, Liu L, Wang J, Jin Q. Identification of a Novel Serum Biomarker for Tuberculosis Infection in Chinese HIV Patients by iTRAQ-Based Quantitative Proteomics. Front Microbiol 2018. [PMID: 29535695 PMCID: PMC5834467 DOI: 10.3389/fmicb.2018.00330] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Tuberculosis (TB) is a major comorbidity in HIV patients as well as a serious co-epidemic. Traditional detection methods are not effective or sensitive for the detection of Mycobacterium tuberculosis at the early stage. TB has become a major cause of lethal on HIV patients. We employed isobaric tags for relative and absolute quantitation (iTRAQ) technology to identify the different host responses in HIV-noTB and HIV-TB patients’ sera. Given the diversity of HIV subtypes, which results in a variety of host responses in different human populations, we focused on the Chinese patients. Of the 25 proteins identified, 7 were increased and 18 were decreased in HIV-TB co-infected patients. These proteins were found to be involved in host immune response processes. We identified a candidate protein, endoglin (ENG), which showed an 4.9 times increase by iTRAQ and 11.5 times increase by ELISA. ENG demonstrated the diagnostic efficacy and presented a novel molecular biomarker for TB in HIV-infected Chinese patients. This study provides new insight into the challenges in the diagnosis and effective management of patients with HIV-TB.
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Affiliation(s)
- Cong Chen
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Tao Yan
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Liguo Liu
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jianmin Wang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qi Jin
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
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Xie J, Han M, Zhang M, Deng H, Wu W. PP5 (PPP5C) is a phosphatase of Dvl2. Sci Rep 2018; 8:2715. [PMID: 29426949 PMCID: PMC5807433 DOI: 10.1038/s41598-018-21124-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 01/30/2018] [Indexed: 11/09/2022] Open
Abstract
Dishevelled (Dvl) family proteins are key mediators of Wnt signalling and function in both canonical and noncanonical branches. Dvl2, the most studied Dvl protein, is extensively regulated by phosphorylation. Several kinases were found to be critical for Dvl2 localisation, stability control and functional segregation. For example, S143-phosphorylated Dvl2 was detected, together with CK1δ/ε, at the centrosome and basal body of primary cilia and plays pivotal roles during ciliogenesis. However, relatively less is known about Dvl dephosphorylation and the phosphatases involved. Here, we identified PP5 (PPP5C) as a phosphatase of Dvl2. PP5 interacts with and can directly dephosphorylate Dvl2. Knockdown of PP5 caused elevated Dvl2 phosphorylation both at the basal level and upon Wnt stimulation. In the Dvl2 protein, S143, the 10B5 cluster and other sites were dephosphorylated by PP5. Interestingly, comparison of PP5 with PP2A, another known Dvl2 phosphatase, revealed that PP5 and PP2A are not fully redundant in the regulation of Dvl2 phosphorylation status. In hTERT-RPE1 cells, PP5 was found at the basal body of cilia, where S143-phosphorylated Dvl2 also resides. Functional assays revealed modest effects on ciliogenesis after PP5 depletion or over-expression. Taken together, our results provided evidence to suggest PP5 as a new phosphatase for Dvl2.
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Affiliation(s)
- Jianlei Xie
- MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Meng Han
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Miaojun Zhang
- MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Haiteng Deng
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wei Wu
- MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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Abstract
Separase is a highly conserved protease required for chromosome segregation. Although observations that separase also regulates membrane trafficking events have been made, it is still not clear how separase achieves this function. Here, we present an extensive ENU mutagenesis suppressor screen aimed at identifying suppressors of sep-1(e2406), a temperature-sensitive maternal effect embryonic lethal separase mutant that primarily attenuates membrane trafficking rather than chromosome segregation. We screened nearly a million haploid genomes and isolated 68 suppressed lines. We identified 14 independent intragenic sep-1(e2406) suppressed lines. These intragenic alleles map to seven SEP-1 residues within the N-terminus, compensating for the original mutation within the poorly conserved N-terminal domain. Interestingly, 47 of the suppressed lines have novel mutations throughout the entire coding region of the pph-5 phosphatase, indicating that this is an important regulator of separase. We also found that a mutation near the MEEVD motif of HSP-90, which binds and activates PPH-5, also rescues sep-1(e2406) mutants. Finally, we identified six potentially novel suppressor lines that fall into five complementation groups. These new alleles provide the opportunity to more exhaustively investigate the regulation and function of separase.
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Protein phosphatase 5 regulates titin phosphorylation and function at a sarcomere-associated mechanosensor complex in cardiomyocytes. Nat Commun 2018; 9:262. [PMID: 29343782 PMCID: PMC5772059 DOI: 10.1038/s41467-017-02483-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 12/04/2017] [Indexed: 12/14/2022] Open
Abstract
Serine/threonine protein phosphatase 5 (PP5) is ubiquitously expressed in eukaryotic cells; however, its function in cardiomyocytes is unknown. Under basal conditions, PP5 is autoinhibited, but enzymatic activity rises upon binding of specific factors, such as the chaperone Hsp90. Here we show that PP5 binds and dephosphorylates the elastic N2B-unique sequence (N2Bus) of titin in cardiomyocytes. Using various binding and phosphorylation tests, cell-culture manipulation, and transgenic mouse hearts, we demonstrate that PP5 associates with N2Bus in vitro and in sarcomeres and is antagonistic to several protein kinases, which phosphorylate N2Bus and lower titin-based passive tension. PP5 is pathologically elevated and likely contributes to hypo-phosphorylation of N2Bus in failing human hearts. Furthermore, Hsp90-activated PP5 interacts with components of a sarcomeric, N2Bus-associated, mechanosensor complex, and blocks mitogen-activated protein-kinase signaling in this complex. Our work establishes PP5 as a compartmentalized, well-controlled phosphatase in cardiomyocytes, which regulates titin properties and kinase signaling at the myofilaments. Protein phosphatase 5 (PP5) is expressed in many cell types but its role in cardiomyocytes is unknown. Here the authors show that PP5 binds and dephosphorylates elastic titin in cardiac sarcomeres, and that PP5 is increased in heart failure, reducing cardiomyocyte compliance.
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45
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Chen YL, Hung MH, Chu PY, Chao TI, Tsai MH, Chen LJ, Hsiao YJ, Shih CT, Hsieh FS, Chen KF. Protein phosphatase 5 promotes hepatocarcinogenesis through interaction with AMP-activated protein kinase. Biochem Pharmacol 2017; 138:49-60. [DOI: 10.1016/j.bcp.2017.05.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/12/2017] [Indexed: 11/27/2022]
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Wang L, Yan F. Deprotonation states of the two active site water molecules regulate the binding of protein phosphatase 5 with its substrate: A molecular dynamics study. Protein Sci 2017; 26:2010-2020. [PMID: 28726316 DOI: 10.1002/pro.3239] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/11/2017] [Accepted: 07/12/2017] [Indexed: 01/01/2023]
Abstract
Protein phosphatase 5 (PP5), mainly localized in human brain, can dephosphorylate tau protein whose high level of phosphorylation is related to Alzheimer's disease. Similar to other protein phosphatases, PP5 has a conserved motif in the catalytic domain that contains two binding sites for manganese (Mn2+ ) ions. Structural data indicate that two active site water molecules, one bridging the two Mn2+ ions and the other terminally coordinated with one of the Mn2+ ions (Mn1), are involved in catalysis. Recently, a density functional theory study revealed that the two water molecules can be both deprotonated to keep a neutral active site for catalysis. The theoretical study gives us an insight into the catalytic mechanism of PP5, but the knowledge of how the deprotonation states of the two water molecules affect the binding of PP5 with its substrate is still lacking. To approach this problem, molecular dynamics simulations were performed to model the four possible deprotonation states. Through structural, dynamical and energetic analyses, the results demonstrate that the deprotonation states of the two water molecules affect the structure of the active site including the distance between the two Mn2+ ions and their coordination, impact the interaction energy of residues R275, R400 and H304 which directly interact with the substrate phosphoserine, and mediate the dynamics of helix αJ which is involved in regulation of the enzyme's activity. Furthermore, the deprotonation state that is preferable for PP5 binding of its substrate has been identified. These findings could provide new design strategy for PP5 inhibitor.
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Affiliation(s)
- Lingyun Wang
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Feng Yan
- School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin, 300387, P. R. China
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Stechschulte LA, Lecka-Czernik B. Reciprocal regulation of PPARγ and RUNX2 activities in marrow mesenchymal stem cells: Fine balance between p38 MAPK and Protein Phosphatase 5. ACTA ACUST UNITED AC 2017; 3:107-113. [PMID: 29276666 DOI: 10.1007/s40610-017-0056-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Purpose of review Post-translational modifications (PTMs), specifically serine phosphorylation, are essential for determination and tuning up an activity of many proteins, including those that are involved in the control of gene transcription. Transcription factors PPARγ2 and RUNX2 are essential for mesenchymal stem cell (MSC) commitment to either adipocyte or osteoblast lineage. This review is summarizing current knowledge how serine phosphorylation PTMs regulate activities of both transcription factors and MSCs lineage commitment. Recent finding Both PPARγ2 and RUNX2 transcriptional activities are regulated by similar PTMs, however with an opposite outcome. The same p38 MAPK mediates serine phosphorylation that leads to activation of RUNX2 and inactivation of PPARγ2. The process of protein phosphorylation is balanced with a process of protein dephosphorylation. Protein phosphatase 5 simultaneously dephosphorylates both proteins, which results in activation of PPARγ2 and inactivation of RUNX2. Summary This review provides a summary of the "yinyang" fine-tuned mechanism by which p38 MAPK and PP5 regulate MSCs lineage commitment.
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Affiliation(s)
- Lance A Stechschulte
- Department of Orthopaedic Surgery.,Center for Diabetes and Endocrine Diseases, University of Toledo Health Sciences Campus, Toledo, Ohio
| | - Beata Lecka-Czernik
- Department of Orthopaedic Surgery.,Physiology and Pharmacology.,Center for Diabetes and Endocrine Diseases, University of Toledo Health Sciences Campus, Toledo, Ohio
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Hong TJ, Park K, Choi EW, Hahn JS. Ro 90-7501 inhibits PP5 through a novel, TPR-dependent mechanism. Biochem Biophys Res Commun 2017; 482:215-220. [DOI: 10.1016/j.bbrc.2016.11.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 11/08/2016] [Indexed: 01/03/2023]
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VanPelt J, Page RC. Unraveling the CHIP:Hsp70 complex as an information processor for protein quality control. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1865:133-141. [PMID: 27863257 DOI: 10.1016/j.bbapap.2016.11.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 11/24/2022]
Abstract
The CHIP:Hsp70 complex stands at the crossroads of the cellular protein quality control system. Hsp70 facilitates active refolding of misfolded client proteins, while CHIP directs ubiquitination of misfolded client proteins bound to Hsp70. The direct competition between CHIP and Hsp70 for the fate of misfolded proteins leads to the question: how does the CHIP:Hsp70 complex execute triage decisions that direct misfolded proteins for either refolding or degradation? The current body of literature points toward action of the CHIP:Hsp70 complex as an information processor that takes inputs in the form of client folding state, dynamics, and posttranslational modifications, then outputs either refolded or ubiquitinated client proteins. Herein we examine the CHIP:Hsp70 complex beginning with the structure and function of CHIP and Hsp70, followed by an examination of recent studies of the interactions and dynamics of the CHIP:Hsp70 complex.
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Affiliation(s)
- Jamie VanPelt
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Richard C Page
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA.
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Structural and functional basis of protein phosphatase 5 substrate specificity. Proc Natl Acad Sci U S A 2016; 113:9009-14. [PMID: 27466404 DOI: 10.1073/pnas.1603059113] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The serine/threonine phosphatase protein phosphatase 5 (PP5) regulates hormone- and stress-induced cellular signaling by association with the molecular chaperone heat shock protein 90 (Hsp90). PP5-mediated dephosphorylation of the cochaperone Cdc37 is essential for activation of Hsp90-dependent kinases. However, the details of this mechanism remain unknown. We determined the crystal structure of a Cdc37 phosphomimetic peptide bound to the catalytic domain of PP5. The structure reveals PP5 utilization of conserved elements of phosphoprotein phosphatase (PPP) structure to bind substrate and provides a template for many PPP-substrate interactions. Our data show that, despite a highly conserved structure, elements of substrate specificity are determined within the phosphatase catalytic domain itself. Structure-based mutations in vivo reveal that PP5-mediated dephosphorylation is required for kinase and steroid hormone receptor release from the chaperone complex. Finally, our data show that hyper- or hypoactivity of PP5 mutants increases Hsp90 binding to its inhibitor, suggesting a mechanism to enhance the efficacy of Hsp90 inhibitors by regulation of PP5 activity in tumors.
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