1
|
Kumar JP, Kosek D, Durell SR, Miller Jenkins LM, Debnath S, Coussens NP, Hall MD, Appella DH, Dyda F, Mazur SJ, Appella E. Crystal structure and mechanistic studies of the PPM1D serine/threonine phosphatase catalytic domain. J Biol Chem 2024; 300:107561. [PMID: 39002674 DOI: 10.1016/j.jbc.2024.107561] [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: 11/29/2023] [Revised: 06/28/2024] [Accepted: 07/03/2024] [Indexed: 07/15/2024] Open
Abstract
Protein phosphatase 1D (PPM1D, Wip1) is induced by the tumor suppressor p53 during DNA damage response signaling and acts as an oncoprotein in several human cancers. Although PPM1D is a potential therapeutic target, insights into its atomic structure were challenging due to flexible regions unique to this family member. Here, we report the first crystal structure of the PPM1D catalytic domain to 1.8 Å resolution. The structure reveals the active site with two Mg2+ ions bound, similar to other structures. The flap subdomain and B-loop, which are crucial for substrate recognition and catalysis, were also resolved, with the flap forming two short helices and three short β-strands that are followed by an irregular loop. Unexpectedly, a nitrogen-oxygen-sulfur bridge was identified in the catalytic domain. Molecular dynamics simulations and kinetic studies provided further mechanistic insights into the regulation of PPM1D catalytic activity. In particular, the kinetic experiments demonstrated a magnesium concentration-dependent lag in PPM1D attaining steady-state velocity, a feature of hysteretic enzymes that show slow transitions compared with catalytic turnover. All combined, these results advance the understanding of PPM1D function and will support the development of PPM1D-targeted therapeutics.
Collapse
Affiliation(s)
- Jay Prakash Kumar
- Laboratory of Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland, United States
| | - Dalibor Kosek
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, United States
| | - Stewart R Durell
- Laboratory of Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland, United States
| | - Lisa M Miller Jenkins
- Laboratory of Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland, United States
| | - Subrata Debnath
- Laboratory of Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland, United States
| | - Nathan P Coussens
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, United States
| | - Matthew D Hall
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, United States
| | - Daniel H Appella
- Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bethesda, Maryland, United States
| | - Fred Dyda
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, United States
| | - Sharlyn J Mazur
- Laboratory of Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland, United States
| | - Ettore Appella
- Laboratory of Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland, United States.
| |
Collapse
|
2
|
Szabo E, Nagy B, Czajlik A, Komlodi T, Ozohanics O, Tretter L, Ambrus A. Mitochondrial Alpha-Keto Acid Dehydrogenase Complexes: Recent Developments on Structure and Function in Health and Disease. Subcell Biochem 2024; 104:295-381. [PMID: 38963492 DOI: 10.1007/978-3-031-58843-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The present work delves into the enigmatic world of mitochondrial alpha-keto acid dehydrogenase complexes discussing their metabolic significance, enzymatic operation, moonlighting activities, and pathological relevance with links to underlying structural features. This ubiquitous family of related but diverse multienzyme complexes is involved in carbohydrate metabolism (pyruvate dehydrogenase complex), the citric acid cycle (α-ketoglutarate dehydrogenase complex), and amino acid catabolism (branched-chain α-keto acid dehydrogenase complex, α-ketoadipate dehydrogenase complex); the complexes all function at strategic points and also participate in regulation in these metabolic pathways. These systems are among the largest multienzyme complexes with at times more than 100 protein chains and weights ranging up to ~10 million Daltons. Our chapter offers a wealth of up-to-date information on these multienzyme complexes for a comprehensive understanding of their significance in health and disease.
Collapse
Affiliation(s)
- Eszter Szabo
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Balint Nagy
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Andras Czajlik
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Timea Komlodi
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Oliver Ozohanics
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Laszlo Tretter
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Attila Ambrus
- Department of Biochemistry, Semmelweis University, Budapest, Hungary.
| |
Collapse
|
3
|
罗 凯, 谢 茂, 杨 为, 李 涛, 姜 春. [Effect of Pp2 cm Gene Silencing on Mouse Macrophage Resistance Against Staphylococcus aureus Infection via TLR Pathway]. SICHUAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF SICHUAN UNIVERSITY. MEDICAL SCIENCE EDITION 2023; 54:941-946. [PMID: 37866950 PMCID: PMC10579066 DOI: 10.12182/20230960206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Indexed: 10/24/2023]
Abstract
Objective To investigate the effect of silencing protein phosphatase 2cm ( Pp2cm) gene on the expression of inflammatory factors in macrophages infected with Staphylococcus aureus ( S. aureus) and the mechanisms involved. Methods The effects of Pp2cm knockdown on inflammatory factors, proliferation, apoptosis, and Toll-like receptor (TLR) signaling were analyzed in RAW 264.7 cells, a murine macrophage cell line, transfected with adenovirus (Ad). The cells were divided into four groups, including Ad-Ctrl group, Ad- Pp2cm group, Ad-Ctrl+ S. aureus group and Ad- Pp2cm+ S. aureus group. Cell transfection was achieved by separately introducing control adenovirus (Ad-Ctrl) or adenovirus targeting the Pp2cm gene (Ad- Pp2cm) and inflammation or the absence of inflammation was induced by applying or not applying S. aureus. The expression of tumor necrosis factor-alpha ( TNF-α), interleukin-1β ( IL-1 β), TLR2, TLR4, Toll-like receptor adaptor protein ( Tirap) and myeloid differentiation factor 88 ( Myd88) was determined by real-time fluorescent quantitative polymerase chain reaction (RT-qPCR). PP2Cm protein expression was determined by Western blot. Cell proliferation was determined by cell counting kit-8 (CCK-8) assay and cell apoptosis was measured by flow cytometry. Results The expression of Pp2cmgene and PP2Cm protein was downregulated in the Ad- Pp2cm group when compared to the Ad-Ctrl group, with the diference showing statistical significance ( P<0.05). When compared to those of the Ad-Ctrl+ S. aureus group, macrophages in the Ad- Pp2cm+ S. aureus group showed significantly increase in the TNF- α and IL-1 β gene levels ( P<0.01). Furthermore, the Ad- Pp2cm group demonstrated elevated gene expression levels of TLR2, TLR4, Tirap and Myd88 in macrophages when compared to the Ad-Ctrl group, with the difference showing statistical significance ( P<0.05). There were no statistically significant differences in cell apoptosis and proliferation between the Ad-Ctrl and Ad- Pp2cm groups. Conclusions Silencing Pp2cm gene promotes the inflammatory response of macrophages to S. aureus infection. Moreover, the TLR pathway plays an important role in the inflammatory activation of macrophages.
Collapse
Affiliation(s)
- 凯腾 罗
- 四川大学华西医院 麻醉科 (成都 610041)Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- 四川大学华西医院 麻醉转化医学国家地方联合工程研究中心 线粒体与代谢研究室 (成都 610041)Laboratory of Mitochondria and Metabolism, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 茂迪 谢
- 四川大学华西医院 麻醉科 (成都 610041)Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 为 杨
- 四川大学华西医院 麻醉科 (成都 610041)Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- 四川大学华西医院 麻醉转化医学国家地方联合工程研究中心 线粒体与代谢研究室 (成都 610041)Laboratory of Mitochondria and Metabolism, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 涛 李
- 四川大学华西医院 麻醉科 (成都 610041)Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- 四川大学华西医院 麻醉转化医学国家地方联合工程研究中心 线粒体与代谢研究室 (成都 610041)Laboratory of Mitochondria and Metabolism, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 春玲 姜
- 四川大学华西医院 麻醉科 (成都 610041)Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- 四川大学华西医院 麻醉转化医学国家地方联合工程研究中心 线粒体与代谢研究室 (成都 610041)Laboratory of Mitochondria and Metabolism, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| |
Collapse
|
4
|
Zhang L, Sang X, Han Y, Abulitibu A, Elken M, Mao Z, Kang S, Yang W, Lu C. The expression of apoptosis related genes in HK-2 cells overexpressing PPM1K was determined by RNA-seq analysis. Front Genet 2022; 13:1004610. [PMID: 36386814 PMCID: PMC9663473 DOI: 10.3389/fgene.2022.1004610] [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: 07/27/2022] [Accepted: 10/18/2022] [Indexed: 01/24/2023] Open
Abstract
Chronic kidney disease (CKD) is a serious disease that endangers human health. It is reported that inhibiting renal cell apoptosis can delay the progress of CKD. Our previous study found that the mice with protein phosphatase Mg2+/Mn2+ dependent 1K (PPM1K) gene deletion had obvious symptoms of glomerular vascular and interstitial vascular dilatation, congestion and hemorrhage, glomerular hemorrhage and necrosis, interstitial fibrous tissue proliferation, decreased urinary creatinine clearance, and increased urinary protein level. In addition, studies have found that PPM1K is essential for cell survival, apoptosis and metabolism. However, no study has confirmed that PPM1K can inhibit renal cell apoptosis. In this study, PPM1K was overexpressed in human kidney-2 cells (HK-2), and the biological process of differentially expressed genes and its effect on apoptosis were comprehensively screened by RNA sequencing (RNA-seq). Through sequencing analysis, we found that there were 796 differentially expressed genes in human renal tubular epithelial cells transfected with PPM1K gene, of which 553 were down-regulated and 243 were up-regulated. Enrichment analysis found that differentially expressed genes may play an important role in amino acid metabolism and biosynthesis. In the GO analysis functional pathway list, we also found that multiple genes can be enriched in apoptosis related pathways, such as G0S2, GADD45A, TRIB3, VEGFA, NUPR1 and other up-regulated genes, and IL-6, MAGED1, CCL2, TP53INP1 and other down-regulated genes. Then we verified these differentially expressed genes by RT-PCR, and found that only the RT-PCR results of G0S2, VEGFA and NUPR1 were consistent with the transcriptome sequencing results. We believe that G0S2, VEGFA, NUPR1 and other genes may participate in the apoptosis process of HK-2 cells induced by PPM1K.In conclusion, these findings provide some data support for the study of HK-2 cell apoptosis mechanism, and also provide a scientific theoretical basis for further study of the effect of PPM1K on kidney disease.
Collapse
Affiliation(s)
- Li Zhang
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China
| | - Xiaohong Sang
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China
| | - Yuanyuan Han
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China
| | - Alpati Abulitibu
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China
| | - Mufunayi Elken
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China
| | - Zhijie Mao
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China
| | - Shaotao Kang
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China
| | - Wenjun Yang
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China,*Correspondence: Wenjun Yang, ; Chen Lu,
| | - Chen Lu
- Nephrology Center of the First Affiliated Hospital of Xinjiang Medical University, Urumqi, China,Xinjiang Clinical Research Center of Renal Replacement Therapy, Urumqi, China,Xinjiang Branch of National Clinical Research Center for Kidney Disease, Urumqi, China,Xinjiang Blood Purification Medical Quality Control Center, Urumqi, China,Institute of Nephrology of Xinjiang, Urumqi, China,*Correspondence: Wenjun Yang, ; Chen Lu,
| |
Collapse
|
5
|
Mann G, Mora S, Madu G, Adegoke OAJ. Branched-chain Amino Acids: Catabolism in Skeletal Muscle and Implications for Muscle and Whole-body Metabolism. Front Physiol 2021; 12:702826. [PMID: 34354601 PMCID: PMC8329528 DOI: 10.3389/fphys.2021.702826] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
Branched-chain amino acids (BCAAs) are critical for skeletal muscle and whole-body anabolism and energy homeostasis. They also serve as signaling molecules, for example, being able to activate mammalian/mechanistic target of rapamycin complex 1 (mTORC1). This has implication for macronutrient metabolism. However, elevated circulating levels of BCAAs and of their ketoacids as well as impaired catabolism of these amino acids (AAs) are implicated in the development of insulin resistance and its sequelae, including type 2 diabetes, cardiovascular disease, and of some cancers, although other studies indicate supplements of these AAs may help in the management of some chronic diseases. Here, we first reviewed the catabolism of these AAs especially in skeletal muscle as this tissue contributes the most to whole body disposal of the BCAA. We then reviewed emerging mechanisms of control of enzymes involved in regulating BCAA catabolism. Such mechanisms include regulation of their abundance by microRNA and by post translational modifications such as phosphorylation, acetylation, and ubiquitination. We also reviewed implications of impaired metabolism of BCAA for muscle and whole-body metabolism. We comment on outstanding questions in the regulation of catabolism of these AAs, including regulation of the abundance and post-transcriptional/post-translational modification of enzymes that regulate BCAA catabolism, as well the impact of circadian rhythm, age and mTORC1 on these enzymes. Answers to such questions may facilitate emergence of treatment/management options that can help patients suffering from chronic diseases linked to impaired metabolism of the BCAAs.
Collapse
Affiliation(s)
| | | | | | - Olasunkanmi A. J. Adegoke
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| |
Collapse
|
6
|
Moreda-Piñeiro J, Cocho JA, Couce ML, Moreda-Piñeiro A, Bermejo-Barrera P. Trace elements in dried blood spots as potential discriminating features for metabolic disorder diagnosis in newborns. Metallomics 2021; 13:6261194. [PMID: 33930140 PMCID: PMC8755940 DOI: 10.1093/mtomcs/mfab018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/26/2021] [Accepted: 04/08/2021] [Indexed: 11/13/2022]
Abstract
Trace elements in dried blood spots (DBSs) from newborns were determined by laser ablation coupled with inductively coupled plasma mass spectrometry, and data were subjected to chemometric evaluation in an attempt to classify healthy newborns and newborns suffering from metabolic disorders. Unsupervised [principal component analysis (PCA) and cluster analysis (CA)] and supervised [linear discriminant analysis (LDA) and soft independent modeling by class analogy (SIMCA)] pattern recognition techniques were used as classification techniques. PCA and CA have shown a clear tendency to form two groups (healthy newborns and newborns suffering from metabolic disorders). LDA and SIMCA have predicted that 90.5% and 83.9% of originally grouped healthy newborn cases were correctly classified by LDA and SIMCA, respectively. In addition, these percentages were 97.6% (LDA) and 80.6% (SIMCA) for DBSs from newborns suffering from metabolic disorders. However, SIMCA has only detected one misclassified DBS from the healthy group, and the lower percentage is attributed to four DBSs from the healthy newborn group and five DBSs from newborns with disorders that were found as belonging to both categories (healthy newborns and newborns with disorders) in the training set. LDA also gave a percentage of grouped maple syrup urine disease (MSUD) cases correctly classified of 100%, although the percentage fells to 66.7% when classifying phenylketonuria (PKU) cases. Finally, essential elements such as Fe, K, Rb, and Zn were found to be matched (correlated) with the concentration of amino acids such as phenylalanine, valine, and leucine, biomarkers linked with MSUD and PKU diseases.
Collapse
Affiliation(s)
- Jorge Moreda-Piñeiro
- Department of Chemistry, Faculty of Sciences, Universidade da Coruña, Grupo Química Analítica Aplicada (QANAP), University Institute of Research in Environmental Studies (IUMA), Centro de Investigaciones Científicas Avanzadas (CICA), Campus de A Coruña, s/n, 15071 A Coruña, Spain
| | - José A Cocho
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, University Hospital of Santiago de Compostela, IDIS, CIBERER, A Choupana, s/n, 15706 Santiago de Compostela, Spain
| | - María Luz Couce
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, University Hospital of Santiago de Compostela, IDIS, CIBERER, A Choupana, s/n, 15706 Santiago de Compostela, Spain
| | - Antonio Moreda-Piñeiro
- Group of Trace Elements, Speciation and Spectroscopy (GETEE), Strategic Grouping in Materials (AEMAT), Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, Universidade de Santiago de Compostela, Avenida das Ciencias, s/n, 15782 Santiago de Compostela, Spain
| | - Pilar Bermejo-Barrera
- Group of Trace Elements, Speciation and Spectroscopy (GETEE), Strategic Grouping in Materials (AEMAT), Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, Universidade de Santiago de Compostela, Avenida das Ciencias, s/n, 15782 Santiago de Compostela, Spain
| |
Collapse
|
7
|
Metal-dependent Ser/Thr protein phosphatase PPM family: Evolution, structures, diseases and inhibitors. Pharmacol Ther 2020; 215:107622. [PMID: 32650009 DOI: 10.1016/j.pharmthera.2020.107622] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 06/29/2020] [Indexed: 02/06/2023]
Abstract
Protein phosphatases and kinases control multiple cellular events including proliferation, differentiation, and stress responses through regulating reversible protein phosphorylation, the most important post-translational modification. Members of metal-dependent protein phosphatase (PPM) family, also known as PP2C phosphatases, are Ser/Thr phosphatases that bind manganese/magnesium ions (Mn2+/Mg2+) in their active center and function as single subunit enzymes. In mammals, there are 20 isoforms of PPM phosphatases: PPM1A, PPM1B, PPM1D, PPM1E, PPM1F, PPM1G, PPM1H, PPM1J, PPM1K, PPM1L, PPM1M, PPM1N, ILKAP, PDP1, PDP2, PHLPP1, PHLPP2, PP2D1, PPTC7, and TAB1, whereas there are only 8 in yeast. Phylogenetic analysis of the DNA sequences of vertebrate PPM isoforms revealed that they can be divided into 12 different classes: PPM1A/PPM1B/PPM1N, PPM1D, PPM1E/PPM1F, PPM1G, PPM1H/PPM1J/PPM1M, PPM1K, PPM1L, ILKAP, PDP1/PDP2, PP2D1/PHLPP1/PHLPP2, TAB1, and PPTC7. PPM-family members have a conserved catalytic core region, which contains the metal-chelating residues. The different isoforms also have isoform specific regions within their catalytic core domain and terminal domains, and these regions may be involved in substrate recognition and/or functional regulation of the phosphatases. The twenty mammalian PPM phosphatases are involved in regulating diverse cellular functions, such as cell cycle control, cell differentiation, immune responses, and cell metabolism. Mutation, overexpression, or deletion of the PPM phosphatase gene results in abnormal cellular responses, which lead to various human diseases. This review focuses on the structures and biological functions of the PPM-phosphatase family and their associated diseases. The development of specific inhibitors against the PPM phosphatase family as a therapeutic strategy will also be discussed.
Collapse
|