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Miyazawa K, Itoh Y, Fu H, Miyazono K. Receptor-activated transcription factors and beyond: multiple modes of Smad2/3-dependent transmission of TGF-β signaling. J Biol Chem 2024; 300:107256. [PMID: 38569937 PMCID: PMC11063908 DOI: 10.1016/j.jbc.2024.107256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/28/2024] [Accepted: 03/05/2024] [Indexed: 04/05/2024] Open
Abstract
Transforming growth factor β (TGF-β) is a pleiotropic cytokine that is widely distributed throughout the body. Its receptor proteins, TGF-β type I and type II receptors, are also ubiquitously expressed. Therefore, the regulation of various signaling outputs in a context-dependent manner is a critical issue in this field. Smad proteins were originally identified as signal-activated transcription factors similar to signal transducer and activator of transcription proteins. Smads are activated by serine phosphorylation mediated by intrinsic receptor dual specificity kinases of the TGF-β family, indicating that Smads are receptor-restricted effector molecules downstream of ligands of the TGF-β family. Smad proteins have other functions in addition to transcriptional regulation, including post-transcriptional regulation of micro-RNA processing, pre-mRNA splicing, and m6A methylation. Recent technical advances have identified a novel landscape of Smad-dependent signal transduction, including regulation of mitochondrial function without involving regulation of gene expression. Therefore, Smad proteins are receptor-activated transcription factors and also act as intracellular signaling modulators with multiple modes of function. In this review, we discuss the role of Smad proteins as receptor-activated transcription factors and beyond. We also describe the functional differences between Smad2 and Smad3, two receptor-activated Smad proteins downstream of TGF-β, activin, myostatin, growth and differentiation factor (GDF) 11, and Nodal.
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Affiliation(s)
- Keiji Miyazawa
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.
| | - Yuka Itoh
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Hao Fu
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Kohei Miyazono
- Department of Applied Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Laboratory for Cancer Invasion and Metastasis, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
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2
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Kobayashi T, Yamazaki K, Shinada J, Mizunuma M, Furukawa K, Chuman Y. Identification of Inhibitors of the Disease-Associated Protein Phosphatase Scp1 Using Antibody Mimetic Molecules. Int J Mol Sci 2024; 25:3737. [PMID: 38612548 PMCID: PMC11011526 DOI: 10.3390/ijms25073737] [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: 02/28/2024] [Revised: 03/18/2024] [Accepted: 03/25/2024] [Indexed: 04/14/2024] Open
Abstract
Protein phosphorylation is a prevalent translational modification, and its dysregulation has been implicated in various diseases, including cancer. Despite its significance, there is a lack of specific inhibitors of the FCP/SCP-type Ser/Thr protein phosphatase Scp1, characterized by high specificity and affinity. In this study, we focused on adnectin, an antibody-mimetic protein, aiming to identify Scp1-specific binding molecules with a broad binding surface that target the substrate-recognition site of Scp1. Biopanning of Scp1 was performed using an adnectin-presenting phage library with a randomized FG loop. We succeeded in identifying FG-1Adn, which showed high affinity and specificity for Scp1. Ala scanning analysis of the Scp1-binding sequence in relation to the FG-1 peptide revealed that hydrophobic residues, including aromatic amino acids, play important roles in Scp1 recognition. Furthermore, FG-1Adn was found to co-localize with Scp1 in cells, especially on the plasma membrane. In addition, Western blotting analysis showed that FG-1Adn increased the phosphorylation level of the target protein of Scp1 in cells, indicating that FG-1Adn can inhibit the function of Scp1. These results suggest that FG-1Adn can be used as a specific inhibitor of Scp1.
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Affiliation(s)
| | | | | | | | | | - Yoshiro Chuman
- Department of Chemistry, Faculty of Science, Niigata University, Niigata 950-2181, Japan; (T.K.); (K.Y.); (J.S.); (M.M.); (K.F.)
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Deng Z, Fan T, Xiao C, Tian H, Zheng Y, Li C, He J. TGF-β signaling in health, disease, and therapeutics. Signal Transduct Target Ther 2024; 9:61. [PMID: 38514615 PMCID: PMC10958066 DOI: 10.1038/s41392-024-01764-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 08/31/2023] [Accepted: 01/31/2024] [Indexed: 03/23/2024] Open
Abstract
Transforming growth factor (TGF)-β is a multifunctional cytokine expressed by almost every tissue and cell type. The signal transduction of TGF-β can stimulate diverse cellular responses and is particularly critical to embryonic development, wound healing, tissue homeostasis, and immune homeostasis in health. The dysfunction of TGF-β can play key roles in many diseases, and numerous targeted therapies have been developed to rectify its pathogenic activity. In the past decades, a large number of studies on TGF-β signaling have been carried out, covering a broad spectrum of topics in health, disease, and therapeutics. Thus, a comprehensive overview of TGF-β signaling is required for a general picture of the studies in this field. In this review, we retrace the research history of TGF-β and introduce the molecular mechanisms regarding its biosynthesis, activation, and signal transduction. We also provide deep insights into the functions of TGF-β signaling in physiological conditions as well as in pathological processes. TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted. Through the summary of previous knowledge and recent updates, this review aims to provide a systematic understanding of TGF-β signaling and to attract more attention and interest to this research area.
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Affiliation(s)
- Ziqin Deng
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Tao Fan
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Chu Xiao
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - He Tian
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Yujia Zheng
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Chunxiang Li
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China.
| | - Jie He
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China.
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4
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Runa F, Ortiz-Soto G, de Barros NR, Kelber JA. Targeting SMAD-Dependent Signaling: Considerations in Epithelial and Mesenchymal Solid Tumors. Pharmaceuticals (Basel) 2024; 17:326. [PMID: 38543112 PMCID: PMC10975212 DOI: 10.3390/ph17030326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 04/01/2024] Open
Abstract
SMADs are the canonical intracellular effector proteins of the TGF-β (transforming growth factor-β). SMADs translocate from plasma membrane receptors to the nucleus regulated by many SMAD-interacting proteins through phosphorylation and other post-translational modifications that govern their nucleocytoplasmic shuttling and subsequent transcriptional activity. The signaling pathway of TGF-β/SMAD exhibits both tumor-suppressing and tumor-promoting phenotypes in epithelial-derived solid tumors. Collectively, the pleiotropic nature of TGF-β/SMAD signaling presents significant challenges for the development of effective cancer therapies. Here, we review preclinical studies that evaluate the efficacy of inhibitors targeting major SMAD-regulating and/or -interacting proteins, particularly enzymes that may play important roles in epithelial or mesenchymal compartments within solid tumors.
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Affiliation(s)
- Farhana Runa
- Department of Biology, California State University Northridge, Northridge, CA 91330, USA
| | | | | | - Jonathan A Kelber
- Department of Biology, California State University Northridge, Northridge, CA 91330, USA
- Department of Biology, Baylor University, Waco, TX 76706, USA
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5
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Gu YY, Liu XS, Lan HY. Therapeutic potential for renal fibrosis by targeting Smad3-dependent noncoding RNAs. Mol Ther 2024; 32:313-324. [PMID: 38093516 PMCID: PMC10861968 DOI: 10.1016/j.ymthe.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/13/2023] [Accepted: 12/11/2023] [Indexed: 01/26/2024] Open
Abstract
Renal fibrosis is a characteristic hallmark of chronic kidney disease (CKD) that ultimately results in renal failure, leaving patients with few therapeutic options. TGF-β is a master regulator of renal fibrosis and mediates progressive renal fibrosis via both canonical and noncanonical signaling pathways. In the canonical Smad signaling, Smad3 is a key mediator in tissue fibrosis and mediates renal fibrosis via a number of noncoding RNAs (ncRNAs). In this regard, targeting Smad3-dependent ncRNAs may offer a specific therapy for renal fibrosis. This review highlights the significance and innovation of TGF-β/Smad3-associated ncRNAs as biomarkers and therapeutic targets in renal fibrogenesis. In addition, the underlying mechanisms of these ncRNAs and their future perspectives in the treatment of renal fibrosis are discussed.
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Affiliation(s)
- Yue-Yu Gu
- State Key Laboratory of Traditional Chinese Medicine Syndrome, Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China; Departments of Medicine and Therapeutics, Li Ka Shing Institute of Health Sciences, and Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong; Department of Pharmacology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China; Departments of Nephrology and Pathology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xu-Sheng Liu
- State Key Laboratory of Traditional Chinese Medicine Syndrome, Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.
| | - Hui-Yao Lan
- Departments of Medicine and Therapeutics, Li Ka Shing Institute of Health Sciences, and Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong; Departments of Nephrology and Pathology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China.
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6
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Lv X, Lu X, Cao J, Luo Q, Ding Y, Peng F, Pataer A, Lu D, Han D, Malmberg E, Chan DW, Wang X, Savage SR, Mao S, Yu J, Peng F, Yan L, Meng H, Maneix L, Han Y, Chen Y, Yao W, Chang EC, Catic A, Lin X, Miles G, Huang P, Sun Z, Burt B, Wang H, Wang J, Yao QC, Zhang B, Roth JA, O’Malley BW, Ellis MJ, Rimawi MF, Ying H, Chen X. Modulation of the proteostasis network promotes tumor resistance to oncogenic KRAS inhibitors. Science 2023; 381:eabn4180. [PMID: 37676964 PMCID: PMC10720158 DOI: 10.1126/science.abn4180] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 07/28/2023] [Indexed: 09/09/2023]
Abstract
Despite substantial advances in targeting mutant KRAS, tumor resistance to KRAS inhibitors (KRASi) remains a major barrier to progress. Here, we report proteostasis reprogramming as a key convergence point of multiple KRASi-resistance mechanisms. Inactivation of oncogenic KRAS down-regulated both the heat shock response and the inositol-requiring enzyme 1α (IRE1α) branch of the unfolded protein response, causing severe proteostasis disturbances. However, IRE1α was selectively reactivated in an ER stress-independent manner in acquired KRASi-resistant tumors, restoring proteostasis. Oncogenic KRAS promoted IRE1α protein stability through extracellular signal-regulated kinase (ERK)-dependent phosphorylation of IRE1α, leading to IRE1α disassociation from 3-hydroxy-3-methylglutaryl reductase degradation (HRD1) E3-ligase. In KRASi-resistant tumors, both reactivated ERK and hyperactivated AKT restored IRE1α phosphorylation and stability. Suppression of IRE1α overcame resistance to KRASi. This study reveals a druggable mechanism that leads to proteostasis reprogramming and facilitates KRASi resistance.
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Affiliation(s)
- Xiangdong Lv
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Xuan Lu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jin Cao
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Qin Luo
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Yao Ding
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Fanglue Peng
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Apar Pataer
- Department of Thoracic and Cardiovascular Surgery, University of Texas MD Anderson Cancer Center, USA
| | - Dong Lu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, USA
- Center for Drug Discovery, Baylor College of Medicine, USA
| | - Dong Han
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Eric Malmberg
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Doug W. Chan
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Xiaoran Wang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Sara R. Savage
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, USA
| | - Sufeng Mao
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jingjing Yu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Fei Peng
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, USA
| | - Liang Yan
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, USA
| | - Huan Meng
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Laure Maneix
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, USA
| | - Yumin Han
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Yiwen Chen
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, USA
| | - Wantong Yao
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, USA
| | - Eric C. Chang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Andre Catic
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, USA
| | - Xia Lin
- Division of Surgical Oncology, Michael E. DeBakey Department of Surgery
| | - George Miles
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, USA
| | - Pengxiang Huang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Zheng Sun
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, USA
| | - Bryan Burt
- Division of Thoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, USA
| | - Huamin Wang
- Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jin Wang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, USA
- Center for Drug Discovery, Baylor College of Medicine, USA
| | - Qizhi Cathy Yao
- Division of Surgical Oncology, Michael E. DeBakey Department of Surgery
| | - Bing Zhang
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, USA
| | - Jack A. Roth
- Department of Thoracic and Cardiovascular Surgery, University of Texas MD Anderson Cancer Center, USA
| | - Bert W. O’Malley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Matthew J. Ellis
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
- Early Oncology, Oncology R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Mothaffar F. Rimawi
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Haoqiang Ying
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, USA
| | - Xi Chen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
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Trypanosoma brucei Tim50 Possesses PAP Activity and Plays a Critical Role in Cell Cycle Regulation and Parasite Infectivity. mBio 2021; 12:e0159221. [PMID: 34517757 PMCID: PMC8546626 DOI: 10.1128/mbio.01592-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Trypanosoma brucei, the infective agent for African trypanosomiasis, possesses a homologue of the translocase of the mitochondrial inner membrane 50 (TbTim50). It has a pair of characteristic phosphatase signature motifs, DXDX(T/V). Here, we demonstrated that, besides its protein phosphatase activity, the recombinant TbTim50 binds and hydrolyzes phosphatidic acid in a concentration-dependent manner. Mutations of D242 and D244, but not of D345and D347, to alanine abolished these activities. In silico structural homology models identified the putative binding interfaces that may accommodate different phosphosubstrates. Interestingly, TbTim50 depletion in the bloodstream form (BF) of T. brucei reduced cardiolipin (CL) levels and decreased mitochondrial membrane potential (ΔΨ). TbTim50 knockdown (KD) also reduced the population of G2/M phase and increased that of G1 phase cells; inhibited segregation and caused overreplication of kinetoplast DNA (kDNA), and reduced BF cell growth. Depletion of TbTim50 increased the levels of AMPK phosphorylation, and parasite morphology was changed with upregulation of expression of a few stumpy marker genes. Importantly, we observed that TbTim50-depleted parasites were unable to establish infection in mice. Proteomics analysis showed reductions in levels of the translation factors, flagellar transport proteins, and many proteasomal subunits, including those of the mitochondrial heat shock locus ATPase (HslVU), which is known to play a role in regulation of kinetoplast DNA (kDNA) replication. Reduction of the level of HslV in TbTim50 KD cells was further validated by immunoblot analysis. Together, our results showed that TbTim50 is essential for mitochondrial function, regulation of kDNA replication, and the cell cycle in the BF. Therefore, TbTim50 is an important target for structure-based drug design to combat African trypanosomiasis.
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Puzanov GA, Senchenko VN. SCP Phosphatases and Oncogenesis. Mol Biol 2021. [DOI: 10.1134/s0026893321030092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Thielen N, Neefjes M, Wiegertjes R, van den Akker G, Vitters E, van Beuningen H, Blaney Davidson E, Koenders M, van Lent P, van de Loo F, van Caam A, van der Kraan P. Osteoarthritis-Related Inflammation Blocks TGF-β's Protective Effect on Chondrocyte Hypertrophy via (de)Phosphorylation of the SMAD2/3 Linker Region. Int J Mol Sci 2021; 22:ijms22158124. [PMID: 34360888 PMCID: PMC8347103 DOI: 10.3390/ijms22158124] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 01/13/2023] Open
Abstract
Osteoarthritis (OA) is a degenerative joint disease characterized by irreversible cartilage damage, inflammation and altered chondrocyte phenotype. Transforming growth factor-β (TGF-β) signaling via SMAD2/3 is crucial for blocking hypertrophy. The post-translational modifications of these SMAD proteins in the linker domain regulate their function and these can be triggered by inflammation through the activation of kinases or phosphatases. Therefore, we investigated if OA-related inflammation affects TGF-β signaling via SMAD2/3 linker-modifications in chondrocytes. We found that both Interleukin (IL)-1β and OA-synovium conditioned medium negated SMAD2/3 transcriptional activity in chondrocytes. This inhibition of TGF-β signaling was enhanced if SMAD3 could not be phosphorylated on Ser213 in the linker region and the inhibition by IL-1β was less if the SMAD3 linker could not be phosphorylated at Ser204. Our study shows evidence that inflammation inhibits SMAD2/3 signaling in chondrocytes via SMAD linker (de)-phosphorylation. The involvement of linker region modifications may represent a new therapeutic target for OA.
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Affiliation(s)
- Nathalie Thielen
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Margot Neefjes
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Renske Wiegertjes
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Guus van den Akker
- Department of Orthopedic Surgery, Maastricht University, 6200 MD Maastricht, The Netherlands;
| | - Elly Vitters
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Henk van Beuningen
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Esmeralda Blaney Davidson
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Marije Koenders
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Peter van Lent
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Fons van de Loo
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Arjan van Caam
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
| | - Peter van der Kraan
- Department of Experimental Rheumatology, Radboud University Medical Center, 6500 MD Nijmegen, The Netherlands; (N.T.); (M.N.); (R.W.); (E.V.); (H.v.B.); (E.B.D.); (M.K.); (P.v.L.); (F.v.d.L.); (A.v.C.)
- Correspondence:
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Specific Smad2/3 Linker Phosphorylation Indicates Esophageal Non-neoplastic and Neoplastic Stem-Like Cells and Neoplastic Development. Dig Dis Sci 2021; 66:1862-1874. [PMID: 32705438 DOI: 10.1007/s10620-020-06489-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/11/2020] [Indexed: 12/09/2022]
Abstract
BACKGROUND There is little known about stem cells in human non-neoplastic and neoplastic esophageal epithelia. We have demonstrated expression of linker threonine-phosphorylated Smad2/3 (pSmad2/3L-Thr), suggesting presence of stem-like cells in mouse esophageal epithelium, and identified presence of pSmad2/3L-Thr-positive cells that might function as cancer stem cells in mouse model of colorectal carcinoma. AIMS We explore whether pSmad2/3L-Thr can be used as a biomarker for stem cells of human esophageal epithelia and/or neoplasms. METHODS We have used esophageal tissues from inpatients undergoing endoscopic submucosal dissection and performed double immunofluorescent staining of pSmad2/3L-Thr and Ki67, CDK4, p63, Sox2, CK14, p53, ALDH1, CD44 or D2-40 after which the sections were stained with hematoxylin and eosin. RESULTS pSmad2/3L-Thr-positive cells showed immunohistochemical co-localization with CDK4, p63, CD44 and Sox2 in the basal and parabasal layers of non-neoplastic esophageal epithelia. In esophageal neoplasms, they showed immunohistochemical co-localization with p53, CDK4, ALDH1 and CD44. There was a significant increase in the percentage of pSmad2/3L-Thr-positive cells in the p53-positive neoplastic cell population with development of esophageal neoplasia. pSmad2/3L-Thr-positive cells localized to the lower section of low-grade intraepithelial neoplasia and were observed up to the upper section in carcinoma in situ. In invasive squamous cell carcinoma, they were scattered throughout the tumor with disappearance of polarity and were found in intraepithelial primary lesions and sites of submucosal and vessel invasion. CONCLUSIONS We determined significant expression of pSmad2/3L-Thr in human esophageal non-neoplastic and neoplastic epithelia, indicating that these are epithelial stem-like cells and cancer stem cells, respectively, that correlate with developing esophageal neoplasms.
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11
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Abdel Mouti M, Pauklin S. TGFB1/INHBA Homodimer/Nodal-SMAD2/3 Signaling Network: A Pivotal Molecular Target in PDAC Treatment. Mol Ther 2021; 29:920-936. [PMID: 33429081 PMCID: PMC7934636 DOI: 10.1016/j.ymthe.2021.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/17/2020] [Accepted: 01/02/2021] [Indexed: 02/06/2023] Open
Abstract
Pancreatic cancer remains a grueling disease that is projected to become the second-deadliest cancer in the next decade. Standard treatment of pancreatic cancer is chemotherapy, which mainly targets the differentiated population of tumor cells; however, it paradoxically sets the roots of tumor relapse by the selective enrichment of intrinsically chemoresistant pancreatic cancer stem cells that are equipped with an indefinite capacity for self-renewal and differentiation, resulting in tumor regeneration and an overall anemic response to chemotherapy. Crosstalk between pancreatic tumor cells and the surrounding stromal microenvironment is also involved in the development of chemoresistance by creating a supportive niche, which enhances the stemness features and tumorigenicity of pancreatic cancer cells. In addition, the desmoplastic nature of the tumor-associated stroma acts as a physical barrier, which limits the intratumoral delivery of chemotherapeutics. In this review, we mainly focus on the transforming growth factor beta 1 (TGFB1)/inhibin subunit beta A (INHBA) homodimer/Nodal-SMAD2/3 signaling network in pancreatic cancer as a pivotal central node that regulates multiple key mechanisms involved in the development of chemoresistance, including enhancement of the stem cell-like properties and tumorigenicity of pancreatic cancer cells, mediating cooperative interactions between pancreatic cancer cells and the surrounding stroma, as well as regulating the deposition of extracellular matrix proteins within the tumor microenvironment.
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Affiliation(s)
- Mai Abdel Mouti
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Headington, University of Oxford, Oxford OX3 7LD, UK
| | - Siim Pauklin
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Headington, University of Oxford, Oxford OX3 7LD, UK.
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12
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Deubiquitinase USP29 promotes gastric cancer cell migration by cooperating with phosphatase SCP1 to stabilize Snail protein. Oncogene 2020; 39:6802-6815. [PMID: 32973332 DOI: 10.1038/s41388-020-01471-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 08/26/2020] [Accepted: 09/15/2020] [Indexed: 01/07/2023]
Abstract
Snail is a master inducer of epithelial-mesenchymal transition (EMT) and metastasis, however, Snail protein is labile and is quickly degraded through the predominate ubiquitination-mediated proteasome pathway. Deubiquitinases (DUBs) can counteract the Snail degradation process to maintain high level of Snail protein in cancer cells. In this study, we screened a cDNA library containing 79 DUBs, and discovered that a panel of DUBs consisting of USP13, USP28, USP29, USP37, OTUD6A, and DUB3 can markedly stabilize Snail protein, with USP29 displaying the strongest activity to prevent Snail degradation. Mechanistically, USP29 enhances the interaction of Snail and SCP1, resulting in simultaneous dephosphorylation and deubiquitination of Snail and thereafter cooperative prevention of Snail degradation. Biologically, ectopic expression of USP29 promotes gastric cancer cell migration, and depletion of Snail abolishes USP29-mediated cell migration; and USP29 can be induced by major EMT and metastatic inducing factors such as TGFβ, TNFα, and hypoxia. More importantly, high expression levels of Snail, USP29, and SCP1 are associated with poor survival and prognosis. Collectively, these data indicate that Snail is a crucial substrate for USP29 to promote cell migration and USP29/SCP1 complex may be new therapeutic targets to treat metastatic cancer.
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13
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Tzavlaki K, Moustakas A. TGF-β Signaling. Biomolecules 2020; 10:biom10030487. [PMID: 32210029 PMCID: PMC7175140 DOI: 10.3390/biom10030487] [Citation(s) in RCA: 343] [Impact Index Per Article: 85.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 02/06/2023] Open
Abstract
Transforming growth factor-β (TGF-β) represents an evolutionarily conserved family of secreted polypeptide factors that regulate many aspects of physiological embryogenesis and adult tissue homeostasis. The TGF-β family members are also involved in pathophysiological mechanisms that underlie many diseases. Although the family comprises many factors, which exhibit cell type-specific and developmental stage-dependent biological actions, they all signal via conserved signaling pathways. The signaling mechanisms of the TGF-β family are controlled at the extracellular level, where ligand secretion, deposition to the extracellular matrix and activation prior to signaling play important roles. At the plasma membrane level, TGF-βs associate with receptor kinases that mediate phosphorylation-dependent signaling to downstream mediators, mainly the SMAD proteins, and mediate oligomerization-dependent signaling to ubiquitin ligases and intracellular protein kinases. The interplay between SMADs and other signaling proteins mediate regulatory signals that control expression of target genes, RNA processing at multiple levels, mRNA translation and nuclear or cytoplasmic protein regulation. This article emphasizes signaling mechanisms and the importance of biochemical control in executing biological functions by the prototype member of the family, TGF-β.
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14
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Identification of a Specific Inhibitor of Human Scp1 Phosphatase Using the Phosphorylation Mimic Phage Display Method. Catalysts 2019. [DOI: 10.3390/catal9100842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Protein phosphatases are divided into tyrosine (Tyr) phosphatases and serine/threonine (Ser/Thr) phosphatases. While substrate trapping mutants are frequently used to identify substrates of Tyr phosphatases, a rapid and simple method to identify Ser/Thr phosphatase substrates is yet to be developed. The TFIIF-associating component of RNA polymerase II C-terminal domain (CTD) phosphatase/small CTD phosphatase (FCP/SCP) phosphatase family is one of the three types of Ser/Thr protein phosphatases. Defects in these phosphatases are correlated with the occurrence of various diseases such as cancer and neuropathy. Recently, we developed phosphorylation mimic phage display (PMPD) method with AlF4−, a methodology to identify substrates for FCP/SCP type Ser/Thr phosphatase Scp1. Here, we report a PMPD method using BeF3− to identify novel substrate peptides bound to Scp1. After screening peptide phages, we identified peptides that bound to Scp1 in a BeF3−-dependent manner. Synthetic phosphopeptide BeM12-1, the sequence of which was isolated at the highest frequency, directly bound to Scp1. The binding was inhibited by adding BeF3−, indicating that the peptide binds to the active center of catalytic site in Scp1. The phosphorylated BeM12-1 worked as a competitive inhibitor of Scp1. Thus, PMPD method may be applicable for the identification of novel substrates and inhibitors of the FCP/SCP phosphatase family.
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15
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Tripathi A, Singha UK, Paromov V, Hill S, Pratap S, Rose K, Chaudhuri M. The Cross Talk between TbTim50 and PIP39, Two Aspartate-Based Protein Phosphatases, Maintains Cellular Homeostasis in Trypanosoma brucei. mSphere 2019; 4:e00353-19. [PMID: 31391278 PMCID: PMC6686227 DOI: 10.1128/msphere.00353-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/08/2019] [Indexed: 12/18/2022] Open
Abstract
Trypanosoma brucei, the infectious agent of a deadly disease known as African trypanosomiasis, undergoes various stresses during its digenetic life cycle. We previously showed that downregulation of T. brucei mitochondrial inner membrane protein translocase 50 (TbTim50), an aspartate-based protein phosphatase and a component of the translocase of the mitochondrial inner membrane (TIM), increased the tolerance of procyclic cells to oxidative stress. Using comparative proteomics analysis and further validating the proteomics results by immunoblotting, here we discovered that TbTim50 downregulation caused an approximately 5-fold increase in the levels of PIP39, which is also an aspartate-based protein phosphatase and is primarily localized in glycosomes. A moderate upregulation of a number of glycosomal enzymes was also noticed due to TbTim50 knockdown. We found that the rate of mitochondrial ATP production by oxidative phosphorylation decreased and that substrate-level phosphorylation increased due to depletion of TbTim50. These results were correlated with relative increases in the levels of trypanosome alternative oxidase and hexokinase and a reduced-growth phenotype in low-glucose medium. The levels and activity of the mitochondrial superoxide dismutase and glutaredoxin levels were increased due to TbTim50 knockdown. Furthermore, we show that TbTim50 downregulation increased the cellular AMP/ATP ratio, and as a consequence, phosphorylation of AMP-activated protein kinase (AMPK) was increased. Knocking down both TbTim50 and TbPIP39 reduced PIP39 levels as well as AMPK phosphorylation and reduced T. brucei tolerance to oxidative stress. These results suggest that TbTim50 and PIP39, two protein phosphatases in mitochondria and glycosomes, respectively, cross talk via the AMPK pathway to maintain cellular homeostasis in the procyclic form of T. bruceiIMPORTANCETrypanosoma brucei, the infectious agent of African trypanosomiasis, must adapt to strikingly different host environments during its digenetic life cycle. Developmental regulation of mitochondrial activities is an essential part of these processes. We have shown previously that mitochondrial inner membrane protein translocase 50 in T. brucei (TbTim50) possesses a dually specific phosphatase activity and plays a role in the cellular stress response pathway. Using proteomics analysis, here we have elucidated a novel connection between TbTim50 and a protein phosphatase of the same family, PIP39, which is also a differentiation-related protein localized in glycosomes. We found that these two protein phosphatases cross talk via the AMPK pathway and modulate cellular metabolic activities under stress. Together, our results indicate the importance of a TbTim50 and PIP39 cascade for communication between mitochondria and other cellular parts in regulation of cell homeostasis in T. brucei.
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Affiliation(s)
- Anuj Tripathi
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Ujjal K Singha
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Victor Paromov
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Salisha Hill
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Siddharth Pratap
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Kristie Rose
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
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Derynck R, Budi EH. Specificity, versatility, and control of TGF-β family signaling. Sci Signal 2019; 12:12/570/eaav5183. [PMID: 30808818 DOI: 10.1126/scisignal.aav5183] [Citation(s) in RCA: 462] [Impact Index Per Article: 92.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Encoded in mammalian cells by 33 genes, the transforming growth factor-β (TGF-β) family of secreted, homodimeric and heterodimeric proteins controls the differentiation of most, if not all, cell lineages and many aspects of cell and tissue physiology in multicellular eukaryotes. Deregulation of TGF-β family signaling leads to developmental anomalies and disease, whereas enhanced TGF-β signaling contributes to cancer and fibrosis. Here, we review the fundamentals of the signaling mechanisms that are initiated upon TGF-β ligand binding to its cell surface receptors and the dependence of the signaling responses on input from and cooperation with other signaling pathways. We discuss how cells exquisitely control the functional presentation and activation of heteromeric receptor complexes of transmembrane, dual-specificity kinases and, thus, define their context-dependent responsiveness to ligands. We also introduce the mechanisms through which proteins called Smads act as intracellular effectors of ligand-induced gene expression responses and show that the specificity and impressive versatility of Smad signaling depend on cross-talk from other pathways. Last, we discuss how non-Smad signaling mechanisms, initiated by distinct ligand-activated receptor complexes, complement Smad signaling and thus contribute to cellular responses.
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Affiliation(s)
- Rik Derynck
- Department of Cell and Tissue Biology and Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California at San Francisco, San Francisco, CA 94143, USA.
| | - Erine H Budi
- Department of Cell and Tissue Biology and Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California at San Francisco, San Francisco, CA 94143, USA
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17
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Ooshima A, Park J, Kim SJ. Phosphorylation status at Smad3 linker region modulates transforming growth factor-β-induced epithelial-mesenchymal transition and cancer progression. Cancer Sci 2019; 110:481-488. [PMID: 30589983 PMCID: PMC6361575 DOI: 10.1111/cas.13922] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/19/2018] [Accepted: 12/23/2018] [Indexed: 01/09/2023] Open
Abstract
Smad3, a major transcription factor in transforming growth factor-β (TGF-β) signaling, plays critical roles in both tumor-suppressive and pro-oncogenic functions. Upon TGF-β stimulation, the C-terminal tail of Smad3 undergoes phosphorylation that is essential for canonical TGF-β signaling. The Smad3 linker region contains serine/threonine phosphorylation sites and can be phosphorylated by intracellular kinases, such as the MAPK family, cyclin-dependent kinase (CDK) family and glycogen synthase kinase-3β (GSK-3β). Previous reports based on cell culture studies by us and others showed that mutation of Smad3 linker phosphorylation sites dramatically intensifies TGF-β responses as well as growth-inhibitory function and epithelial-mesenchymal transition (EMT), suggesting that Smad3 linker phosphorylation suppresses TGF-β transcriptional activities. However, recent discoveries of Smad3-interacting molecules that preferentially bind phosphorylated Smad3 linker serine/threonine residues have shown a multitude of signal transductions that either enhance or suppress TGF-β responses associated with Smad3 turnover or cancer progression. This review aims at providing new insight into the perplexing mechanisms of TGF-β signaling affected by Smad3 linker phosphorylation and further attempts to gain insight into elimination and protection of TGF-β-mediated oncogenic and growth-suppressive signals, respectively.
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Affiliation(s)
- Akira Ooshima
- Precision Medicine Research Center, Advanced Institutes of Convergence Technology, Suwon, Korea
| | - Jinah Park
- Precision Medicine Research Center, Advanced Institutes of Convergence Technology, Suwon, Korea
| | - Seong-Jin Kim
- Precision Medicine Research Center, Advanced Institutes of Convergence Technology, Suwon, Korea.,Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Korea
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18
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Impaired mammary tumor formation and metastasis by the point mutation of a Smad3 linker phosphorylation site. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3664-3671. [DOI: 10.1016/j.bbadis.2018.08.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 08/08/2018] [Accepted: 08/23/2018] [Indexed: 02/06/2023]
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19
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Peng JX, Liang SY, Li L. sFRP1 exerts effects on gastric cancer cells through GSK3β/Rac1‑mediated restraint of TGFβ/Smad3 signaling. Oncol Rep 2018; 41:224-234. [PMID: 30542739 PMCID: PMC6278527 DOI: 10.3892/or.2018.6838] [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: 03/01/2018] [Accepted: 10/11/2018] [Indexed: 02/07/2023] Open
Abstract
Secreted frizzled-related protein 1 (sFRP1) is an inhibitor of canonical Wnt signaling; however, previous studies have determined a tumor-promoting function of sFRP1 in a number of different cancer types. A previous study demonstrated that sFRP1 overexpression was associated with an aggressive phenotype and the activation of transforming growth factor β (TGFβ) signaling. sFRP1 overexpression and sFRP1 knockdown cell models were established. Immunoblotting was conducted to examine the protein levels of the associated molecules. Immunofluorescence staining followed by confocal microscopy was performed to visualize the cytoskeleton alterations and subcellular localization of key proteins. sFRP1 overexpression restored glycogen synthase kinase 3β (GSK3β) activity, which activated Rac family small GTPase 1 (Rac1). GSK3β and Rac1 mediated the effect of sFRP1 on the positive regulation of cell growth and migration/invasion. Inhibition of GSK3β or Rac1 abolished the regulation of sFRP1 on TGFβ/SMAD family member 3 (Smad3) signaling and the aggressive phenotype; however, GSK3β or Rac1 overexpression increased cell migration/invasion and restrained Smad3 activity by preventing its nuclear translocation and limiting its transcriptional activity. The present study demonstrated a tumor-promoting function of sFRP1-overexpression by selectively activating TGFβ signaling in gastric cancer cells. GSK3β and Rac1 serve an important function in mediating the sFRP1-induced malignant alterations and signaling changes.
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Affiliation(s)
- Ji-Xiang Peng
- Department of Gastrointestinal Surgery, Guangzhou First People's Hospital, The Second Affiliated Hospital of South China University of Technology, Guangzhou, Guangdong 510180, P.R. China
| | - Shun-Yu Liang
- Department of Gastrointestinal Surgery, Guangzhou First Municipal People's Hospital, Affiliated Guangzhou Medical College, Guangzhou, Guangdong 510180, P.R. China
| | - Li Li
- Department of Gastrointestinal Surgery, Guangzhou First People's Hospital, The Second Affiliated Hospital of South China University of Technology, Guangzhou, Guangdong 510180, P.R. China
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20
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Sun S, Liu S, Zhang Z, Zeng W, Sun C, Tao T, Lin X, Feng XH. Phosphatase UBLCP1 controls proteasome assembly. Open Biol 2018; 7:rsob.170042. [PMID: 28539385 PMCID: PMC5451543 DOI: 10.1098/rsob.170042] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/20/2017] [Indexed: 12/26/2022] Open
Abstract
Ubiquitin-like domain-containing C-terminal domain phosphatase 1 (UBLCP1), an FCP/SCP phosphatase family member, was identified as the first proteasome phosphatase. UBLCP1 binds to proteasome subunit Rpn1 and dephosphorylates the proteasome in vitro. However, it is still unclear which proteasome subunit(s) are the bona fide substrate(s) of UBLCP1 and the precise mechanism for proteasome regulation remains elusive. Here, we show that UBLCP1 selectively binds to the 19S regulatory particle (RP) through its interaction with Rpn1, but not the 20S core particle (CP) or the 26S proteasome holoenzyme. In the RP, UBLCP1 dephosphorylates the subunit Rpt1, impairs its ATPase activity, and consequently disrupts the 26S proteasome assembly, yet it has no effects on the RP assembly from precursor complexes. The Rpn1-binding and phosphatase activities of UBLCP1 are essential for its function on Rpt1 dephosphorylation and proteasome activity both in vivo and in vitro. Our study establishes the essential role of the UBLCP1/Rpn1/Rpt1 complex in regulating proteasome assembly.
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Affiliation(s)
- Shuangwu Sun
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Sisi Liu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Zhengmao Zhang
- Michael E. DeBakey, Department of Surgery, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Wang Zeng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Chuang Sun
- Michael E. DeBakey, Department of Surgery, Houston, TX, USA
| | - Tao Tao
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, People's Republic of China
| | - Xia Lin
- Michael E. DeBakey, Department of Surgery, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Xin-Hua Feng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China .,Michael E. DeBakey, Department of Surgery, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
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21
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Hu X, Kan H, Boye A, Jiang Y, Wu C, Yang Y. Mitogen-activated protein kinase inhibitors reduce the nuclear accumulation of phosphorylated Smads by inhibiting Imp 7 or Imp 8 in HepG2 cells. Oncol Lett 2018; 15:4867-4872. [PMID: 29552126 PMCID: PMC5840705 DOI: 10.3892/ol.2018.7926] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/30/2018] [Indexed: 11/19/2022] Open
Abstract
The transforming growth factor (TGF)-β/Smad signaling pathway is involved in hepatocellular carcinoma development. Smad2 and Smad3 are phosphorylated following TGF-β1 stimulation and subsequently oligomerize with Smad4 to form the Smad2/3/4 complex, which translocates into the nucleus and regulates target genes, including plasminogen activator inhibitor type 1 (PAI1). Importin (Imp)7 and Imp8 are responsible for transporting phosphorylated (p)Smad2/3 and Smad4 into the nucleus. In our previous study, it was demonstrated that mitogen-activated protein kinase (MAPK) inhibitors, including inhibitors of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 could inhibit the transcription of PAI1, but ERK inhibitor had no significant effect on the phosphorylation of Smad2/3, and the formation of Smad2/3/4 complexes, which was different from the effect of JNK or p38 inhibitor. We hypothesized that MAPK inhibitors, particularly ERK inhibitor, reduced the transport of Smads into the nucleus by affecting Imp7 and Imp8. To confirm this hypothesis, HepG2 cells were incubated with different MAPK inhibitors for 5 h and subsequently stimulated with TGF-β1 for 1 h. Next, the intracellular locations of Smads (pSmad2C, pSmad2L, pSmad3C, pSmad3L and Smad4) and Imp7/8 were detected using immunofluorescence staining assays, and the expression of Imp7/8 was investigated using immunoblotting. It was revealed that JNK or p38 inhibitor decreased the phosphorylation of Smad2C, Smad2L and Smad3L, and affected their nuclear accumulation. Although only inhibiting the phosphorylation of Smad2C, ERK inhibitor affected the nuclear accumulation of pSmad2C, pSmad2L, pSmad3C and pSmad3L. The three MAPK inhibitors attenuated the nuclear distribution of Smad4, and the expression and nuclear accumulation of Imp7. ERK and JNK inhibitors attenuated the expression and nuclear accumulation of Imp8. Thus, the results of the present study suggest that MAPK inhibitors, particularly ERK inhibitor, modulate the nuclear accumulation of Smads via the inhibition of Imp 7/8.
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Affiliation(s)
- Xiangpeng Hu
- Department of Pharmacology, Institute of Natural Medicine, Anhui Medical University, Hefei, Anhui 230032, P.R. China.,Digestive Department, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230601, P.R. China
| | - Hongwei Kan
- Department of Pharmacology, Institute of Natural Medicine, Anhui Medical University, Hefei, Anhui 230032, P.R. China
| | - Alex Boye
- Department of Pharmacology, Institute of Natural Medicine, Anhui Medical University, Hefei, Anhui 230032, P.R. China
| | - Yufeng Jiang
- Department of Pharmacology, Institute of Natural Medicine, Anhui Medical University, Hefei, Anhui 230032, P.R. China
| | - Chao Wu
- Department of Pharmacology, Institute of Natural Medicine, Anhui Medical University, Hefei, Anhui 230032, P.R. China
| | - Yan Yang
- Department of Pharmacology, Institute of Natural Medicine, Anhui Medical University, Hefei, Anhui 230032, P.R. China
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22
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Cao J, Yu Y, Zhang Z, Chen X, Hu Z, Tong Q, Chang J, Feng XH, Lin X. SCP4 Promotes Gluconeogenesis Through FoxO1/3a Dephosphorylation. Diabetes 2018; 67:46-57. [PMID: 28851713 PMCID: PMC5741142 DOI: 10.2337/db17-0546] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/21/2017] [Indexed: 11/13/2022]
Abstract
FoxO1 and FoxO3a (collectively FoxO1/3a) proteins regulate a wide array of cellular processes, including hepatic gluconeogenesis. Phosphorylation of FoxO1/3a is a key event that determines its subcellular location and transcriptional activity. During glucose synthesis, the activity of FoxO1/3a is negatively regulated by Akt-mediated phosphorylation, which leads to the cytoplasmic retention of FoxO1/3a. However, the nuclear phosphatase that directly regulates FoxO1/3a remains to be identified. In this study, we discovered a nuclear phosphatase, SCP4/CTDSPL2 (SCP4), that dephosphorylated FoxO1/3a and promoted FoxO1/3a transcription activity. We found that SCP4 enhanced the transcription of FoxO1/3a target genes encoding PEPCK1 and G6PC, key enzymes in hepatic gluconeogenesis. Ectopic expression of SCP4 increased, while knockdown of SCP4 inhibited, glucose production. Moreover, we demonstrated that gene ablation of SCP4 led to hypoglycemia in neonatal mice. Consistent with the positive role of SCP4 in gluconeogenesis, expression of SCP4 was regulated under pathophysiological conditions. SCP4 expression was induced by glucose deprivation in vitro and in vivo and was elevated in obese mice caused by genetic (Avy) and dietary (high-fat) changes. Thus, our findings provided experimental evidence that SCP4 regulates hepatic gluconeogenesis and could serve as a potential target for the prevention and treatment of diet-induced glucose intolerance and type 2 diabetes.
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Affiliation(s)
- Jin Cao
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Yi Yu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Zhengmao Zhang
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Xi Chen
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Zhaoyong Hu
- Department of Medicine, Baylor College of Medicine, Houston, TX
| | - Qiang Tong
- Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX
| | - Jiang Chang
- Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX
| | - Xin-Hua Feng
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Xia Lin
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
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23
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Son B, Kwon T, Lee S, Han I, Kim W, Youn H, Youn B. CYP2E1 regulates the development of radiation-induced pulmonary fibrosis via ER stress- and ROS-dependent mechanisms. Am J Physiol Lung Cell Mol Physiol 2017; 313:L916-L929. [PMID: 28798253 DOI: 10.1152/ajplung.00144.2017] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 07/05/2017] [Accepted: 08/01/2017] [Indexed: 12/15/2022] Open
Abstract
Radiation-induced pulmonary fibrosis (RIPF) is one of the most common side effects of lung cancer radiotherapy. This study was conducted to identify the molecular mechanism responsible for RIPF. We revealed that the transcriptional level of cytochrome P450 2E1 (CYP2E1) was elevated by examining expression profile analysis of RIPF mouse models. We also confirmed that CYP2E1 regulated levels of endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) in alveolar epithelial type II (AE2) cells and lung fibroblasts. Inhibition of CYP2E1 via its siRNA or inhibitor significantly attenuated epithelial-to-mesenchymal transition and apoptosis of AE2 cells, as well as myofibroblast formation induced by radiation. Finally, the effects of a CYP2E1 inhibitor on development of RIPF were evaluated by in vivo studies. Taken together, the results of the present study suggest that CYP2E1 is an important mediator of RIPF development that functions by increasing cellular ER stress and ROS levels.
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Affiliation(s)
- Beomseok Son
- Department of Integrated Biological Science, Pusan National University, Busan, Republic of Korea
| | - TaeWoo Kwon
- Department of Integrated Biological Science, Pusan National University, Busan, Republic of Korea.,Laboratory of Low Dose Risk Assessment, National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Sungmin Lee
- Department of Integrated Biological Science, Pusan National University, Busan, Republic of Korea
| | - IkJoon Han
- Department of Biological Sciences, Pusan National University, Busan, Republic of Korea
| | - Wanyeon Kim
- Department of Biological Sciences, Pusan National University, Busan, Republic of Korea.,Integrative Graduate Program of Ship and Offshore Plant Technology for Ocean Energy Resource, Pusan National University, Busan, Republic of Korea; and
| | - HyeSook Youn
- Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul, Republic of Korea
| | - BuHyun Youn
- Department of Integrated Biological Science, Pusan National University, Busan, Republic of Korea; .,Department of Biological Sciences, Pusan National University, Busan, Republic of Korea
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24
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Winans S, Flynn A, Malhotra S, Balagopal V, Beemon KL. Integration of ALV into CTDSPL and CTDSPL2 genes in B-cell lymphomas promotes cell immortalization, migration and survival. Oncotarget 2017; 8:57302-57315. [PMID: 28915671 PMCID: PMC5593642 DOI: 10.18632/oncotarget.19328] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/09/2017] [Indexed: 01/29/2023] Open
Abstract
Avian leukosis virus induces tumors in chickens by integrating into the genome and altering expression of nearby genes. Thus, ALV can be used as an insertional mutagenesis tool to identify novel genes involved in tumorigenesis. Deep sequencing analysis of viral integration sites has identified CTDSPL and CTDSPL2 as common integration sites in ALV-induced B-cell lymphomas, suggesting a potential role in driving oncogenesis. We show that in tumors with integrations in these genes, the viral promoter is driving the expression of a truncated fusion transcript. Overexpression in cultured chick embryo fibroblasts reveals that CTDSPL and CTDSPL2 have oncogenic properties, including promoting cell migration. We also show that CTDSPL2 has a previously uncharacterized role in protecting cells from apoptosis induced by oxidative stress. Further, the truncated viral fusion transcripts of both CTDSPL and CTDSPL2 promote immortalization in primary cell culture.
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Affiliation(s)
- Shelby Winans
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Alyssa Flynn
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sanandan Malhotra
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Vidya Balagopal
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Karen L Beemon
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
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25
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Ardito F, Giuliani M, Perrone D, Troiano G, Lo Muzio L. The crucial role of protein phosphorylation in cell signaling and its use as targeted therapy (Review). Int J Mol Med 2017; 40:271-280. [PMID: 28656226 PMCID: PMC5500920 DOI: 10.3892/ijmm.2017.3036] [Citation(s) in RCA: 676] [Impact Index Per Article: 96.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/11/2017] [Indexed: 12/31/2022] Open
Abstract
Protein phosphorylation is an important cellular regulatory mechanism as many enzymes and receptors are activated/deactivated by phosphorylation and dephosphorylation events, by means of kinases and phosphatases. In particular, the protein kinases are responsible for cellular transduction signaling and their hyperactivity, malfunction or overexpression can be found in several diseases, mostly tumors. Therefore, it is evident that the use of kinase inhibitors can be valuable for the treatment of cancer. In this review, we discuss the mechanism of action of phosphorylation, with particular attention to the importance of phosphorylation under physiological and pathological conditions. We also discuss the possibility of using kinase inhibitors in the treatment of tumors.
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Affiliation(s)
- Fatima Ardito
- Department of Clinical and Experimental Medicine, Foggia University, I-71122 Foggia, Italy
| | - Michele Giuliani
- Department of Clinical and Experimental Medicine, Foggia University, I-71122 Foggia, Italy
| | - Donatella Perrone
- Department of Clinical and Experimental Medicine, Foggia University, I-71122 Foggia, Italy
| | - Giuseppe Troiano
- Department of Clinical and Experimental Medicine, Foggia University, I-71122 Foggia, Italy
| | - Lorenzo Lo Muzio
- Department of Clinical and Experimental Medicine, Foggia University, I-71122 Foggia, Italy
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26
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Liao P, Wang W, Li Y, Wang R, Jin J, Pang W, Chen Y, Shen M, Wang X, Jiang D, Pang J, Liu M, Lin X, Feng XH, Wang P, Ge X. Palmitoylated SCP1 is targeted to the plasma membrane and negatively regulates angiogenesis. eLife 2017; 6:e22058. [PMID: 28440748 PMCID: PMC5404917 DOI: 10.7554/elife.22058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 03/25/2017] [Indexed: 12/12/2022] Open
Abstract
SCP1 as a nuclear transcriptional regulator acts globally to silence neuronal genes and to affect the dephosphorylation of RNA Pol ll. However, we report the first finding and description of SCP1 as a plasma membrane-localized protein in various cancer cells using EGFP- or other epitope-fused SCP1. Membrane-located SCP1 dephosphorylates AKT at serine 473, leading to the abolishment of serine 473 phosphorylation that results in suppressed angiogenesis and a decreased risk of tumorigenesis. Consistently, we observed increased AKT phosphorylation and angiogenesis followed by enhanced tumorigenesis in Ctdsp1 (which encodes SCP1) gene - knockout mice. Importantly, we discovered that the membrane localization of SCP1 is crucial for impeding angiogenesis and tumor growth, and this localization depends on palmitoylation of a conserved cysteine motif within its NH2 terminus. Thus, our study discovers a novel mechanism underlying SCP1 shuttling between the plasma membrane and nucleus, which constitutes a unique pathway in transducing AKT signaling that is closely linked to angiogenesis and tumorigenesis.
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Affiliation(s)
- Peng Liao
- Department of Central Laboratory, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Weichao Wang
- Department of Central Laboratory, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Yu Li
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Rui Wang
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Jiali Jin
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Weijuan Pang
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Yunfei Chen
- Department of Central Laboratory, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Mingyue Shen
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Xinbo Wang
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Dongyang Jiang
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jinjiang Pang
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Mingyao Liu
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Xia Lin
- Department of Surgery, Baylor College of Medicine, Houston, United States
| | - Xin-Hua Feng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Zhejiang, China
| | - Ping Wang
- Department of Central Laboratory, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
- School of Life Science and Technology, Tongji University, Shanghai, China
| | - Xin Ge
- Department of Clinical Laboratory Medicine, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
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27
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Cellular Dynamics Controlled by Phosphatases. J Indian Inst Sci 2017. [DOI: 10.1007/s41745-016-0016-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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28
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Liao P, Wang W, Ge X. In vitro Dephosphorylation Assay of c-Myc. Bio Protoc 2017; 7:e2011. [DOI: 10.21769/bioprotoc.2011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Revised: 10/22/2016] [Accepted: 12/21/2016] [Indexed: 11/02/2022] Open
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29
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Xu P, Lin X, Feng XH. Posttranslational Regulation of Smads. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a022087. [PMID: 27908935 DOI: 10.1101/cshperspect.a022087] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Transforming growth factor β (TGF-β) family signaling dictates highly complex programs of gene expression responses, which are extensively regulated at multiple levels and vary depending on the physiological context. The formation, activation, and destruction of two major functional complexes in the TGF-β signaling pathway (i.e., the TGF-β receptor complexes and the Smad complexes that act as central mediators of TGF-β signaling) are direct targets for posttranslational regulation. Dysfunction of these complexes often leads or contributes to pathogenesis in cancer and fibrosis and in cardiovascular, and autoimmune diseases. Here we discuss recent insights into the roles of posttranslational modifications in the functions of the receptor-activated Smads in the common Smad4 and inhibitory Smads, and in the control of the physiological responses to TGF-β. It is now evident that these modifications act as decisive factors in defining the intensity and versatility of TGF-β responsiveness. Thus, the characterization of posttranslational modifications of Smads not only sheds light on how TGF-β controls physiological and pathological processes but may also guide us to manipulate the TGF-β responses for therapeutic benefits.
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Affiliation(s)
- Pinglong Xu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xia Lin
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030
| | - Xin-Hua Feng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China.,Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030.,Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
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30
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Jo E, Park SJ, Choi YS, Jeon WK, Kim BC. Kaempferol Suppresses Transforming Growth Factor-β1-Induced Epithelial-to-Mesenchymal Transition and Migration of A549 Lung Cancer Cells by Inhibiting Akt1-Mediated Phosphorylation of Smad3 at Threonine-179. Neoplasia 2016; 17:525-37. [PMID: 26297431 PMCID: PMC4547409 DOI: 10.1016/j.neo.2015.06.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 06/16/2015] [Accepted: 06/23/2015] [Indexed: 01/21/2023] Open
Abstract
Kaempferol, a natural dietary flavonoid, is well known to possess chemopreventive and therapeutic anticancer efficacy; however, its antimetastatic effects have not been mechanistically studied so far in any cancer model. This study was aimed to investigate the inhibitory effect and accompanying mechanisms of kaempferol on epithelial-to-mesenchymal transition (EMT) and cell migration induced by transforming growth factor-β1 (TGF-β1). In human A549 non–small lung cancer cells, kaempferol strongly blocked the enhancement of cell migration by TGF-β1–induced EMT through recovering the loss of E-cadherin and suppressing the induction of mesenchymal markers as well as the upregulation of TGF-β1–mediated matrix metalloproteinase-2 activity. Interestingly, kaempferol reversed TGF-β1–mediated Snail induction and E-cadherin repression by weakening Smad3 binding to the Snail promoter without affecting its C-terminus phosphorylation, complex formation with Smad4, and nuclear translocation under TGF-β1 stimulation. Mechanism study revealed that the phosphorylation of Smad3 linker region induced by TGF-β1 was required for the induction of EMT and cell migration, and selective downregulation of the phosphorylation of Smad3 at Thr179 residue (not Ser204, Ser208, and Ser213) in the linker region was responsible for the inhibition by kaempferol of TGF-β1–induced EMT and cell migration. Furthermore, Akt1 was required for TGF-β1–mediated induction of EMT and cell migration and directly phosphorylated Smad3 at Thr179, and kaempferol completely abolished TGF-β1–induced Akt1 phosphorylation. In summary, kaempferol blocks TGF-β1–induced EMT and migration of lung cancer cells by inhibiting Akt1-mediated phosphorylation of Smad3 at Thr179 residue, providing the first evidence of a molecular mechanism for the anticancer effect of kaempferol.
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Affiliation(s)
- Eunji Jo
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea
| | - Seong Ji Park
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea
| | - Yu Sun Choi
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea
| | - Woo-Kwang Jeon
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea
| | - Byung-Chul Kim
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea.
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31
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Sun T, Fu J, Shen T, Lin X, Liao L, Feng XH, Xu J. The Small C-terminal Domain Phosphatase 1 Inhibits Cancer Cell Migration and Invasion by Dephosphorylating Ser(P)68-Twist1 to Accelerate Twist1 Protein Degradation. J Biol Chem 2016; 291:11518-28. [PMID: 26975371 DOI: 10.1074/jbc.m116.721795] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Indexed: 11/06/2022] Open
Abstract
Twist1 is a basic helix-loop-helix transcription factor that strongly promotes epithelial-to-mesenchymal transition, migration, invasion, and metastasis of cancer cells. The MAPK-phosphorylated Twist1 on its serine 68 (Ser(P)(68)-Twist1) has a significantly enhanced stability and function to drive cancer cell invasion and metastasis. However, the phosphatase that dephosphorylates Ser(P)(68)-Twist1 and destabilizes Twist1 has not been identified and characterized. In this study, we screened a serine/threonine phosphatase cDNA expression library in HEK293T cells with ectopically coexpressed Twist1. We found that the small C-terminal domain phosphatase 1 (SCP1) specifically dephosphorylates Ser(P)(68)-Twist1 in both cell-free reactions and living cells. SCP1 uses its amino acid residues 43-63 to interact with the N terminus of Twist1. Increased SCP1 expression in cells decreased Ser(P)(68)-Twist1 and total Twist1 proteins, whereas knockdown of SCP1 increased Ser(P)(68)-Twist1 and total Twist1 proteins. Furthermore, the levels of SCP1 are negatively correlated with Twist1 protein levels in several cancer cell lines. SCP1-dephosphorylated Twist1 undergoes fast degradation via the ubiquitin-proteasome pathway. Importantly, an increase in SCP1 expression in breast cancer cells with either endogenous or ectopically expressed Twist1 largely inhibits the Twist1-induced epithelial-to-mesenchymal transition phenotype and the migration and invasion capabilities of these cells. These results indicate that SCP1 is the phosphatase that counterregulates the MAPK-mediated phosphorylation of Ser(68)-Twist1. Thus, an increase in SCP1 expression and activity may be a useful strategy for eliminating the detrimental roles of Twist1 in cancer cells.
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Affiliation(s)
- Tong Sun
- From the Department of Molecular and Cellular Biology
| | - Junjiang Fu
- From the Department of Molecular and Cellular Biology, the Institute for Cancer Medicine, Research Center for Preclinical Medicine and College of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan 646000, China, and
| | - Tao Shen
- From the Department of Molecular and Cellular Biology
| | - Xia Lin
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030
| | - Lan Liao
- From the Department of Molecular and Cellular Biology
| | - Xin-Hua Feng
- From the Department of Molecular and Cellular Biology, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030, the Life Sciences Institute and Innovation Center for Cell Signaling Networks, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jianming Xu
- From the Department of Molecular and Cellular Biology, the Institute for Cancer Medicine, Research Center for Preclinical Medicine and College of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan 646000, China, and
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32
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Sun G, Hu Z, Min Z, Yan X, Guan Z, Su H, Fu Y, Ma X, Chen YG, Zhang MQ, Tao Q, Wu W. Small C-terminal Domain Phosphatase 3 Dephosphorylates the Linker Sites of Receptor-regulated Smads (R-Smads) to Ensure Transforming Growth Factor β (TGFβ)-mediated Germ Layer Induction in Xenopus Embryos. J Biol Chem 2015; 290:17239-49. [PMID: 26013826 DOI: 10.1074/jbc.m115.655605] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Indexed: 01/27/2023] Open
Abstract
Germ layer induction is one of the earliest events shortly after fertilization that initiates body formation of vertebrate embryos. In Xenopus, the maternally deposited transcriptional factor VegT promotes the expression of zygotic Nodal/Activin ligands that further form a morphogen gradient along the vegetal-animal axis and trigger the induction of the three germ layers. Here we found that SCP3 (small C-terminal domain phosphatase 3) is maternally expressed and vegetally enriched in Xenopus embryos and is essential for the timely induction of germ layers. SCP3 is required for the full activation of Nodal/Activin and bone morphogenetic protein signals and functions via dephosphorylation in the linker regions of receptor-regulated Smads. Consistently, the linker regions of receptor-regulated Smads are heavily phosphorylated in fertilized eggs, and this phosphorylation is gradually removed when embryos approach the midblastula transition. Knockdown of maternal SCP3 attenuates these dephosphorylation events and the activation of Nodal/Activin and bone morphogenetic protein signals after midblastula transition. This study thus suggested that the maternal SCP3 serves as a vegetally enriched, intrinsic factor to ensure a prepared status of Smads for their activation by the upcoming ligands during germ layer induction of Xenopus embryos.
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Affiliation(s)
- Guanni Sun
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhirui Hu
- the Bioinformatics Division, Center for Synthetic and Systems Biology, TNLIST, Tsinghua University, Beijing 100084, China
| | - Zheying Min
- the School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaohua Yan
- the State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China, and
| | - Zhenpo Guan
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hanxia Su
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yu Fu
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaopeng Ma
- the Bioinformatics Division, Center for Synthetic and Systems Biology, TNLIST, Tsinghua University, Beijing 100084, China
| | - Ye-Guang Chen
- the State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China, and
| | - Michael Q Zhang
- the Bioinformatics Division, Center for Synthetic and Systems Biology, TNLIST, Tsinghua University, Beijing 100084, China, the Department of Biological Sciences, Center for Systems Biology, University of Texas at Dallas, Richardson, Texas 75080
| | - Qinghua Tao
- the School of Life Sciences, Tsinghua University, Beijing 100084, China,
| | - Wei Wu
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China,
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33
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FOXO target gene CTDSP2 regulates cell cycle progression through Ras and p21(Cip1/Waf1). Biochem J 2015; 469:289-98. [PMID: 25990325 PMCID: PMC4613505 DOI: 10.1042/bj20140831] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 05/20/2015] [Indexed: 01/07/2023]
Abstract
Growth factor controlled activity of forkhead box O transcription factors results in altered gene expression, including expression of CTDSP2 (C-terminal domain small phosphatase 2). CTDSP2 can regulate cell cycle progression through Ras and the cyclin-dependent kinase inhibitor p21Cip1/Waf1. Activity of FOXO (forkhead box O) transcription factors is inhibited by growth factor–PI3K (phosphoinositide 3-kinase)–PKB (protein kinase B)/Akt signalling to control a variety of cellular processes including cell cycle progression. Through comparative analysis of a number of microarray datasets we identified a set of genes commonly regulated by FOXO proteins and PI3K–PKB/Akt, which includes CTDSP2 (C-terminal domain small phosphatase 2). We validated CTDSP2 as a genuine FOXO target gene and show that ectopic CTDSP2 can induce cell cycle arrest. We analysed transcriptional regulation after CTDSP2 expression and identified extensive regulation of genes involved in cell cycle progression, which depends on the phosphatase activity of CTDSP2. The most notably regulated gene is the CDK (cyclin-dependent kinase) inhibitor p21Cip1/Waf1 and in the present study we show that p21Cip1/Waf1 is partially responsible for the cell cycle arrest through decreasing cyclin–CDK activity. Our data suggest that CTDSP2 induces p21Cip1/Waf1 through increasing the activity of Ras. As has been described previously, Ras induces p21Cip1/Waf1 through p53-dependent and p53-independent pathways and indeed both p53 and MEK inhibition can mitigate the CTDSP2-induced p21Cip1/Waf1 mRNA up-regulation. In support of Ras activation by CTDSP2, depletion of endogenous CTDSP2 results in reduced Ras activity and thus CTDSP2 seems to be part of a larger set of genes regulated by FOXO proteins, which increase growth factor signalling upon FOXO activation.
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34
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Macias MJ, Martin-Malpartida P, Massagué J. Structural determinants of Smad function in TGF-β signaling. Trends Biochem Sci 2015; 40:296-308. [PMID: 25935112 DOI: 10.1016/j.tibs.2015.03.012] [Citation(s) in RCA: 273] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 03/23/2015] [Accepted: 03/27/2015] [Indexed: 02/08/2023]
Abstract
Smad transcription factors are central to the signal transduction pathway that mediates the numerous effects of the transforming growth factor β (TGF-β) superfamily of cytokines in metazoan embryo development as well as in adult tissue regeneration and homeostasis. Although Smad proteins are conserved, recent genome-sequencing projects have revealed their sequence variation in metazoan evolution, human polymorphisms, and cancer. Structural studies of Smads bound to partner proteins and target DNA provide a framework for understanding the significance of these evolutionary and pathologic sequence variations. We synthesize the extant mutational and structural data to suggest how genetic variation in Smads may affect the structure, regulation, and function of these proteins. We also present a web application that compares Smad sequences and displays Smad protein structures and their disease-associated variants.
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Affiliation(s)
- Maria J Macias
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, 08028 Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain.
| | - Pau Martin-Malpartida
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Joan Massagué
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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35
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Wang W, Liao P, Shen M, Chen T, Chen Y, Li Y, Lin X, Ge X, Wang P. SCP1 regulates c-Myc stability and functions through dephosphorylating c-Myc Ser62. Oncogene 2015; 35:491-500. [PMID: 25893300 DOI: 10.1038/onc.2015.106] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 01/28/2015] [Accepted: 02/27/2015] [Indexed: 02/06/2023]
Abstract
Serine 62 (Ser62) phosphorylation affects the c-Myc protein stability in cancer cells. However, the mechanism for dephosphorylating c-Myc is not well understood. In this study, we identified carboxyl-terminal domain RNA polymerase II polypeptide A small phosphatase 1 (SCP1) as a novel phosphatase specifically dephosphorylating c-Myc Ser62. Ectopically expressed SCP1 strongly dephosphorylated c-Myc Ser62, destabilized c-Myc protein and suppressed c-Myc transcriptional activity. Knockdown of SCP1 increased the c-Myc protein levels in liver cancer cells. SCP1 interacted with c-Myc both in vivo and in vitro. In addition, Ser245 at the C-terminus of SCP1 was essential for its phosphatase activity towards c-Myc. Functionally, SCP1 negatively regulated the cancer cell proliferation. Collectively, our findings indicate that SCP1 is a potential tumor suppressor for liver cancers through dephosphorylating c-Myc Ser62.
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Affiliation(s)
- W Wang
- Department of Central Laboratory, Shanghai 10th People's Hospital, Tongji University, Shanghai, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - P Liao
- Department of Central Laboratory, Shanghai 10th People's Hospital, Tongji University, Shanghai, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - M Shen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - T Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Y Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Y Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - X Lin
- Department of Surgery, Baylor College of Medicine, Houston, TX, USA
| | - X Ge
- Department of Central Laboratory, Shanghai 10th People's Hospital, Tongji University, Shanghai, China
| | - P Wang
- Department of Central Laboratory, Shanghai 10th People's Hospital, Tongji University, Shanghai, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China.,School of Life Science and Technology, Tongji University, Shanghai, China
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Hong J, Kim H, Park C, Son M, Lee KW, Kim YJ. Identification of Undifferentiated Embryonic Cell Transcription Factor 1 as a Potential Substrate of Carboxyl-Terminal Domain Small Phosphatases. JOURNAL OF THE KOREAN CHEMICAL SOCIETY-DAEHAN HWAHAK HOE JEE 2015. [DOI: 10.5012/jkcs.2015.59.2.188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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R HR, Kim H, Noh K, Kim YJ. The diverse roles of RNA polymerase II C-terminal domain phosphatase SCP1. BMB Rep 2015; 47:192-6. [PMID: 24755554 PMCID: PMC4163886 DOI: 10.5483/bmbrep.2014.47.4.060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Indexed: 11/20/2022] Open
Abstract
RNA polymerase II carboxyl-terminal domain (pol II CTD) phosphatases are a newly emerging family of phosphatases that are members of DXDX (T/V). The subfamily includes Small CTD phosphatases, like SCP1, SCP2, SCP3, TIMM50, HSPC129 and UBLCP. Extensive study of SCP1 has elicited the diversified roles of the small C terminal domain phosphatase. The SCP1 plays a vital role in various biological activities, like neuronal gene silencing and preferential Ser5 dephosphorylation, acts as a cardiac hypertrophy inducer with the help of its intronic miRNAs, and has shown a key role in cell cycle regulation. This short review offers an explanation of the mechanism of action of small CTD phosphatases, in different biological activities and metabolic processes. [BMB Reports 2014; 47(4): 192-196]
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Affiliation(s)
- Harikrishna Reddy R
- Departments of Applied Biochemistry Research Center, Konkuk University, Chungju 380-701, Korea
| | - Hackyoung Kim
- Departments of Applied Biochemistry Research Center, Konkuk University, Chungju 380-701, Korea
| | - Kwangmo Noh
- Departments of Nanotechnology Research Center, Konkuk University, Chungju 380-701, Korea
| | - Young Jun Kim
- Departments of Applied Biochemistry and Nanotechnology Research Center, Konkuk University, Chungju 380-701, Korea
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Gordian E, Li J, Pevzner Y, Mediavilla-Varela M, Luddy K, Ohaegbulam K, Daniel KG, Haura EB, Muñoz-Antonia T. Transforming growth factor β signaling overcomes dasatinib resistance in lung cancer. PLoS One 2014; 9:e114131. [PMID: 25501935 PMCID: PMC4263601 DOI: 10.1371/journal.pone.0114131] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 10/03/2014] [Indexed: 12/22/2022] Open
Abstract
Lung cancer is the second most common cancer and the leading cause of cancer-related deaths. Despite recent advances in the development of targeted therapies, patients with advanced disease remain incurable, mostly because metastatic non-small cell lung carcinomas (NSCLC) eventually become resistant to tyrosine kinase inhibitors (TKIs). Kinase inhibitors have the potential for target promiscuity because the kinase super family is the largest family of druggable genes that binds to a common substrate (ATP). As a result, TKIs often developed for a specific purpose have been found to act on other targets. Drug affinity chromatography has been used to show that dasatinib interacts with the TGFβ type I receptor (TβR-I), a serine-threonine kinase. To determine the potential biological relevance of this association, we studied the combined effects of dasatinib and TGFβ on lung cancer cell lines. We found that dasatinib treatment alone had very little effect; however, when NSCLC cell lines were treated with a combination of TGFβ and dasatinib, apoptosis was induced. Combined TGFβ-1 + dasatinib treatment had no effect on the activity of Smad2 or other non-canonical TGFβ intracellular mediators. Interestingly, combined TGFβ and dasatinib treatment resulted in a transient increase in p-Smad3 (seen after 3 hours). In addition, when NSCLC cells were treated with this combination, the pro-apoptotic protein BIM was up-regulated. Knockdown of the expression of Smad3 using Smad3 siRNA also resulted in a decrease in BIM protein, suggesting that TGFβ-1 + dasatinib-induced apoptosis is mediated by Smad3 regulation of BIM. Dasatinib is only effective in killing EGFR mutant cells, which is shown in only 10% of NSCLCs. Therefore, the observation that wild-type EGFR lung cancers can be manipulated to render them sensitive to killing by dasatinib could have important implications for devising innovative and potentially more efficacious treatment strategies for this disease.
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Affiliation(s)
- Edna Gordian
- Molecular Oncology Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 33612, United States of America
| | - Jiannong Li
- Department of Thoracic Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 33612, United States of America
| | - Yuri Pevzner
- Chemical Biology Core, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 33612, United States of America
| | - Melanie Mediavilla-Varela
- Immunology Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 33612, United States of America
| | - Kimberly Luddy
- Cancer Imaging & Metabolism Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 33612, United States of America
| | - Kim Ohaegbulam
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461, United States of America
| | - Kenyon G. Daniel
- Chemical Biology Core, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 33612, United States of America
| | - Eric B. Haura
- Department of Thoracic Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 33612, United States of America
| | - Teresita Muñoz-Antonia
- Molecular Oncology Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida 33612, United States of America
- * E-mail:
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Lin YC, Lu LT, Chen HY, Duan X, Lin X, Feng XH, Tang MJ, Chen RH. SCP phosphatases suppress renal cell carcinoma by stabilizing PML and inhibiting mTOR/HIF signaling. Cancer Res 2014; 74:6935-46. [PMID: 25293974 DOI: 10.1158/0008-5472.can-14-1330] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The tumor-suppressor protein promyelocytic leukemia (PML) is aberrantly degraded in multiple types of human cancers through mechanisms that are incompletely understood. Here, we show that the phosphatase SCP1 and its isoforms SCP2/3 dephosphorylate PML at S518, thereby blocking PML ubiquitination and degradation mediated by the prolyl isomerase Pin1 and the ubiquitin ligase KLHL20. Clinically, SCP1 and SCP3 are downregulated in clear cell renal cell carcinoma (ccRCC) and these events correlated with PMLS518 phosphorylation, PML turnover, and high-grade tumors. Restoring SCP1-mediated PML stabilization not only inhibited malignant features of ccRCC, including proliferation, migration, invasion, tumor growth, and tumor angiogenesis, but also suppressed the mTOR-HIF pathway. Furthermore, blocking PML degradation in ccRCC by SCP1 overexpression or Pin1 inhibition enhanced the tumor-suppressive effects of the mTOR inhibitor temsirolimus. Taken together, our results define a novel pathway of PML degradation in ccRCC that involves SCP downregulation, revealing contributions of this pathway to ccRCC progression and offering a mechanistic rationale for combination therapies that jointly target PML degradation and mTOR inhibition for ccRCC treatment.
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Affiliation(s)
- Yu-Ching Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan. Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Li-Ting Lu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan. Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Hsin-Yi Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan. Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Xueyan Duan
- Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas. Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
| | - Xia Lin
- Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas
| | - Xin-Hua Feng
- Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas. Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
| | - Ming-Jer Tang
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan
| | - Ruey-Hwa Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan. Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
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Fukudome A, Aksoy E, Wu X, Kumar K, Jeong IS, May K, Russell WK, Koiwa H. Arabidopsis CPL4 is an essential C-terminal domain phosphatase that suppresses xenobiotic stress responses. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:27-39. [PMID: 25041272 DOI: 10.1111/tpj.12612] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 06/27/2014] [Accepted: 07/02/2014] [Indexed: 05/20/2023]
Abstract
Eukaryotic gene expression is both promoted and inhibited by the reversible phosphorylation of the C-terminal domain of RNA polymerase II (pol II CTD). More than 20 Arabidopsis genes encode CTD phosphatase homologs, including four CTD phosphatase-like (CPL) family members. Although in vitro CTD phosphatase activity has been established for some CPLs, none have been shown to be involved in the phosphoregulation of pol II in vivo. Here we report that CPL4 is a CTD phosphatase essential for the viability of Arabidopsis thaliana. Mass spectrometry analysis identified the pol II subunits RPB1, RPB2 and RPB3 in the affinity-purified CPL4 complex. CPL4 dephosphorylates both Ser2- and Ser5-PO(4) of the CTD in vitro, with a preference for Ser2-PO(4). Arabidopsis plants overexpressing CPL4 accumulated hypophosphorylated pol II, whereas RNA interference-mediated silencing of CPL4 promoted hyperphosphorylation of pol II. A D128A mutation in the conserved DXDXT motif of the CPL4 catalytic domain resulted in a dominant negative form of CPL4, the overexpression of which inhibited transgene expression in transient assays. Inhibition was abolished by truncation of the phosphoprotein-binding Breast Cancer 1 C-terminal domain of CPL4, suggesting that both catalytic function and protein-protein interaction are essential for CPL4-mediated regulation of gene expression. We were unable to recover a homozygous cpl4 mutant, probably due to the zygotic lethality of this mutation. The reduction in CPL4 levels in CPL4(RNAi) plants increased transcript levels of a suite of herbicide/xenobiotic-responsive genes and improved herbicide tolerance, thus suggesting an additional role for CPL4 as a negative regulator of the xenobiotic detoxification pathway.
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Affiliation(s)
- Akihito Fukudome
- Molecular and Environmental Plant Sciences, Department of Horticultural Sciences, Vegetable and Fruit Development Center, Texas A&M University, College Station, TX, 77843, USA
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Zhao Y, Xiao M, Sun B, Zhang Z, Shen T, Duan X, Yu PB, Feng XH, Lin X. C-terminal domain (CTD) small phosphatase-like 2 modulates the canonical bone morphogenetic protein (BMP) signaling and mesenchymal differentiation via Smad dephosphorylation. J Biol Chem 2014; 289:26441-26450. [PMID: 25100727 PMCID: PMC4176200 DOI: 10.1074/jbc.m114.568964] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 08/05/2014] [Indexed: 01/10/2023] Open
Abstract
The bone morphogenetic protein (BMP) signaling pathway regulates a wide range of cellular responses in metazoans. A key step in the canonical BMP signaling is the phosphorylation and activation of transcription factors Smad1, Smad5, and Smad8 (collectively Smad1/5/8) by the type I BMP receptors. We previously identified PPM1A as a phosphatase toward dephosphorylation of all receptor-regulated Smads (R-Smads), including Smad1/5/8. Here we report another nuclear phosphatase named SCP4/CTDSPL2, belonging to the FCP/SCP family, as a novel Smad phosphatase in the nucleus. SCP4 physically interacts with and specifically dephosphorylates Smad1/5/8, and as a result attenuates BMP-induced transcriptional responses. Knockdown of SCP4 in multipotent mesenchymal C2C12 cells leads to increased expression of BMP target genes and consequently promotes BMP-induced osteogenic differentiation. Collectively, our results demonstrate that SCP4, as a Smad phosphatase, plays a critical role in BMP-induced signaling and cellular functions.
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Affiliation(s)
- Yulan Zhao
- Life Sciences Institute, and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Mu Xiao
- Life Sciences Institute, and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Baoguo Sun
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030; Department of Molecular Physiology and Biophysics, and Baylor College of Medicine, Houston, Texas 77030
| | - Zhengmao Zhang
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030
| | - Tao Shen
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030; Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and
| | - Xueyan Duan
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Paul Borchyung Yu
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Xin-Hua Feng
- Life Sciences Institute, and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, Zhejiang 310058, China,; Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030; Department of Molecular Physiology and Biophysics, and Baylor College of Medicine, Houston, Texas 77030; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030,.
| | - Xia Lin
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030.
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42
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Shen T, Sun C, Zhang Z, Xu N, Duan X, Feng XH, Lin X. Specific control of BMP signaling and mesenchymal differentiation by cytoplasmic phosphatase PPM1H. Cell Res 2014; 24:727-41. [PMID: 24732009 DOI: 10.1038/cr.2014.48] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/19/2014] [Accepted: 02/26/2014] [Indexed: 12/15/2022] Open
Abstract
Bone morphogenetic proteins (BMPs) belong to the TGF-β superfamily of structurally related signaling proteins that regulate a wide array of cellular functions. The key step in BMP signal transduction is the BMP receptor-mediated phosphorylation of transcription factors Smad1, 5, and 8 (collectively Smad1/5/8), which leads to the subsequent activation of BMP-induced gene transcription in the nucleus. In this study, we describe the identification and characterization of PPM1H as a novel cytoplasm-localized Smad1/5/8-specific phosphatase. PPM1H directly interacts with Smad1/5/8 through its Smad-binding domain, and dephosphorylates phospho-Smad1/5/8 (P-Smad1/5/8) in the cytoplasm. Ectopic expression of PPM1H attenuates BMP signaling, whereas loss of PPM1H activity or expression greatly enhances BMP-dependent gene regulation and mesenchymal differentiation. In conclusion, this study suggests that PPM1H acts as a gatekeeper to prevent excessive BMP signaling through dephosphorylation and subsequent nuclear exclusion of P-Smad1/5/8 proteins.
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Affiliation(s)
- Tao Shen
- 1] Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA [2] Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA [3] Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX 77030, USA
| | - Chuang Sun
- 1] Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA [2] Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zhengmao Zhang
- Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ningyi Xu
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xueyan Duan
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xin-Hua Feng
- 1] Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China [2] Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA [3] Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA [4] Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xia Lin
- Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
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Matsuzaki K. Smad phospho-isoforms direct context-dependent TGF-β signaling. Cytokine Growth Factor Rev 2013; 24:385-99. [PMID: 23871609 DOI: 10.1016/j.cytogfr.2013.06.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 06/12/2013] [Indexed: 02/06/2023]
Abstract
Better understanding of TGF-β signaling has deepened our appreciation of normal epithelial cell homeostasis and its dysfunction in such human disorders as cancer and fibrosis. Smad proteins, which convey signals from TGF-β receptors to the nucleus, possess intermediate linker regions connecting Mad homology domains. Membrane-bound, cytoplasmic, and nuclear protein kinases differentially phosphorylate Smad2 and Smad3 to create C-tail (C), the linker (L), or dually (L/C) phosphorylated (p, phospho-) isoforms. According to domain-specific phosphorylation, distinct transcriptional responses, and selective metabolism, Smad phospho-isoform pathways can be grouped into 4 types: cytostatic pSmad3C signaling, mitogenic pSmad3L (Ser-213) signaling, invasive/fibrogenic pSmad2L (Ser-245/250/255)/C or pSmad3L (Ser-204)/C signaling, and mitogenic/migratory pSmad2/3L (Thr-220/179)/C signaling. We outline how responses to TGF-β change through the multiple Smad phospho-isoforms as normal epithelial cells mature from stem cells through progenitors to differentiated cells, and further reflect upon how constitutive Ras-activating mutants favor the Smad phospho-isoform pathway promoting tumor progression. Finally, clinical analyses of reversible Smad phospho-isoform signaling during human carcinogenesis could assess effectiveness of interventions aimed at reducing human cancer risk. Spatiotemporally separate, functionally different Smad phospho-isoforms have been identified in specific cells and tissues, answering long-standing questions about context-dependent TGF-β signaling.
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Affiliation(s)
- Koichi Matsuzaki
- Department of Gastroenterology and Hepatology, Kansai Medical University, 10-15 Fumizonocho, Moriguchi, Osaka 570-8506, Japan.
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44
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Jin J, Pawson T. Modular evolution of phosphorylation-based signalling systems. Philos Trans R Soc Lond B Biol Sci 2012; 367:2540-55. [PMID: 22889906 DOI: 10.1098/rstb.2012.0106] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Phosphorylation sites are formed by protein kinases ('writers'), frequently exert their effects following recognition by phospho-binding proteins ('readers') and are removed by protein phosphatases ('erasers'). This writer-reader-eraser toolkit allows phosphorylation events to control a broad range of regulatory processes, and has been pivotal in the evolution of new functions required for the development of multi-cellular animals. The proteins that comprise this system of protein kinases, phospho-binding targets and phosphatases are typically modular in organization, in the sense that they are composed of multiple globular domains and smaller peptide motifs with binding or catalytic properties. The linkage of these binding and catalytic modules in new ways through genetic recombination, and the selection of particular domain combinations, has promoted the evolution of novel, biologically useful processes. Conversely, the joining of domains in aberrant combinations can subvert cell signalling and be causative in diseases such as cancer. Major inventions such as phosphotyrosine (pTyr)-mediated signalling that flourished in the first multi-cellular animals and their immediate predecessors resulted from stepwise evolutionary progression. This involved changes in the binding properties of interaction domains such as SH2 and their linkage to new domain types, and alterations in the catalytic specificities of kinases and phosphatases. This review will focus on the modular aspects of signalling networks and the mechanism by which they may have evolved.
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Affiliation(s)
- Jing Jin
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada.
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45
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Jasnovidova O, Stefl R. The CTD code of RNA polymerase II: a structural view. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 4:1-16. [DOI: 10.1002/wrna.1138] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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46
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Differential regulation of Smad3 and of the type II transforming growth factor-β receptor in mitosis: implications for signaling. PLoS One 2012; 7:e43459. [PMID: 22927969 PMCID: PMC3425481 DOI: 10.1371/journal.pone.0043459] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 07/24/2012] [Indexed: 01/17/2023] Open
Abstract
The response to transforming growth factor-β (TGF-β) depends on cellular context. This context is changed in mitosis through selective inhibition of vesicle trafficking, reduction in cell volume and the activation of mitotic kinases. We hypothesized that these alterations in cell context may induce a differential regulation of Smads and TGF-β receptors. We tested this hypothesis in mesenchymal-like ovarian cancer cells, arrested (or not) in mitosis with 2-methoxyestradiol (2ME2). In mitosis, without TGF-β stimulation, Smad3 was phosphorylated at the C-terminus and linker regions and localized to the mitotic spindle. Phosphorylated Smad3 interacted with the negative regulators of Smad signaling, Smurf2 and Ski, and failed to induce a transcriptional response. Moreover, in cells arrested in mitosis, Smad3 levels were progressively reduced. These phosphorylations and reduction in the levels of Smad3 depended on ERK activation and Mps1 kinase activity, and were abrogated by increasing the volume of cells arrested in mitosis with hypotonic medium. Furthermore, an Mps1-dependent phosphorylation of GFP-Smad3 was also observed upon its over-expression in interphase cells, suggesting a mechanism of negative regulation which counters increases in Smad3 concentration. Arrest in mitosis also induced a block in the clathrin-mediated endocytosis of the type II TGF-β receptor (TβRII). Moreover, following the stimulation of mitotic cells with TGF-β, the proteasome-mediated attenuation of TGF-β receptor activity, the degradation and clearance of TβRII from the plasma membrane, and the clearance of the TGF-β ligand from the medium were compromised, and the C-terminus phosphorylation of Smad3 was prolonged. We propose that the reduction in Smad3 levels, its linker phosphorylation, and its association with negative regulators (observed in mitosis prior to ligand stimulation) represent a signal attenuating mechanism. This mechanism is balanced by the retention of active TGF-β receptors at the plasma membrane. Together, both mechanisms allow for a regulated cellular response to TGF-β stimuli in mitosis.
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47
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Tarasewicz E, Jeruss JS. Phospho-specific Smad3 signaling: impact on breast oncogenesis. Cell Cycle 2012; 11:2443-51. [PMID: 22659843 DOI: 10.4161/cc.20546] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Members of the TGFβ superfamily are known to exert a myriad of physiologic and pathologic growth controlling influences on mammary development and oncogenesis. In epithelial cells, TGFβ signaling inhibits cell growth through cytostatic and pro-apoptotic activities but can also induce cancer cell EMT and, thus, has a dichotomous role in breast cancer biology. Mechanisms governing this switch are the subject of active investigation. Smad3 is a critical intracellular mediator of TGFβ signaling regulated through phosphorylation by the TGFβ receptor complex at the C terminus. Smad3 is also a substrate for several other kinases that phosphorylate additional sites within the Smad protein. This discovery has expanded the understanding of the significance and complexity of TGFβ signaling through Smads. This review highlights recent advances revealing the critical role of phospho-specific Smad3 in malignancy and illustrates the potential prognostic and therapeutic impact of Smad3 phospho-isoforms in breast cancer.
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Affiliation(s)
- Elizabeth Tarasewicz
- Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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48
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Seifried A, Schultz J, Gohla A. Human HAD phosphatases: structure, mechanism, and roles in health and disease. FEBS J 2012; 280:549-71. [PMID: 22607316 DOI: 10.1111/j.1742-4658.2012.08633.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Phosphatases of the haloacid dehalogenase (HAD) superfamily of hydrolases are an ancient and very large class of enzymes that have evolved to dephosphorylate a wide range of low- and high molecular weight substrates with often exquisite specificities. HAD phosphatases constitute approximately one-fifth of all human phosphatase catalytic subunits. While the overall sequence similarity between HAD phosphatases is generally very low, family members can be identified based on the presence of a characteristic Rossmann-like fold and the active site sequence DxDx(V/T). HAD phosphatases employ an aspartate residue as a nucleophile in a magnesium-dependent phosphoaspartyl transferase reaction. Although there is genetic evidence demonstrating a causal involvement of some HAD phosphatases in diseases such as cancer, cardiovascular, metabolic and neurological disorders, the physiological roles of many of these enzymes are still poorly understood. In this review, we discuss the structure and evolution of human HAD phosphatases, and summarize their known functions in health and disease.
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Affiliation(s)
- Annegrit Seifried
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
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49
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Xu P, Liu J, Derynck R. Post-translational regulation of TGF-β receptor and Smad signaling. FEBS Lett 2012; 586:1871-84. [PMID: 22617150 DOI: 10.1016/j.febslet.2012.05.010] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 05/06/2012] [Accepted: 05/07/2012] [Indexed: 01/17/2023]
Abstract
TGF-β family signaling through Smads is conceptually a simple and linear signaling pathway, driven by sequential phosphorylation, with type II receptors activating type I receptors, which in turn activate R-Smads. Nevertheless, TGF-β family proteins induce highly complex programs of gene expression responses that are extensively regulated, and depend on the physiological context of the cells. Regulation of TGF-β signaling occurs at multiple levels, including TGF-β activation, formation, activation and destruction of functional TGF-β receptor complexes, activation and degradation of Smads, and formation of Smad transcription complexes at regulatory gene sequences that cooperate with a diverse set of DNA binding transcription factors and coregulators. Here we discuss recent insights into the roles of post-translational modifications and molecular interaction networks in the functions of receptors and Smads in TGF-β signal responses. These layers of regulation demonstrate how a simple signaling system can be coopted to exert exquisitely regulated, complex responses.
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Affiliation(s)
- Pinglong Xu
- Department of Cell and Tissue Biology, Programs in Cell Biology and Developmental Biology, University of California, San Francisco, CA, USA
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50
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Han J, Denli AM, Gage FH. The enemy within: intronic miR-26b represses its host gene, ctdsp2, to regulate neurogenesis. Genes Dev 2012; 26:6-10. [PMID: 22215805 DOI: 10.1101/gad.184416.111] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Differentiation of multipotent stem cells occurs through the highly coordinated control of gene expression. Repressor element 1 (RE1) silencing transcription factor (REST), a master transcriptional regulator in neuronal stem cells, restricts neuronal gene expression. REST activity is context-dependent and is modified by its cofactors, such as Ctdsp2. In this issue of Genes & Development, Dill and colleagues (pp. 25-30) report on the microRNA-mediated regulation of neural differentiation. Interestingly, this microRNA is post-transcriptionally regulated and modulates expression of its host gene, ctdsp2.
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Affiliation(s)
- Jinju Han
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, California 92037, USA
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