1
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Zhang H, Read A, Cataisson C, Yang HH, Lee WC, Turk BE, Yuspa SH, Luo J. Protein phosphatase 6 activates NF-κB to confer sensitivity to MAPK pathway inhibitors in KRAS- and BRAF-mutant cancer cells. Sci Signal 2024; 17:eadd5073. [PMID: 38743809 DOI: 10.1126/scisignal.add5073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 04/25/2024] [Indexed: 05/16/2024]
Abstract
The Ras-mitogen-activated protein kinase (MAPK) pathway is a major target for cancer treatment. To better understand the genetic pathways that modulate cancer cell sensitivity to MAPK pathway inhibitors, we performed a CRISPR knockout screen with MAPK pathway inhibitors on a colorectal cancer (CRC) cell line carrying mutant KRAS. Genetic deletion of the catalytic subunit of protein phosphatase 6 (PP6), encoded by PPP6C, rendered KRAS- and BRAF-mutant CRC and BRAF-mutant melanoma cells more resistant to these inhibitors. In the absence of MAPK pathway inhibition, PPP6C deletion in CRC cells decreased cell proliferation in two-dimensional (2D) adherent cultures but accelerated the growth of tumor spheroids in 3D culture and tumor xenografts in vivo. PPP6C deletion enhanced the activation of nuclear factor κB (NF-κB) signaling in CRC and melanoma cells and circumvented the cell cycle arrest and decreased cyclin D1 abundance induced by MAPK pathway blockade in CRC cells. Inhibiting NF-κB activity by genetic and pharmacological means restored the sensitivity of PPP6C-deficient cells to MAPK pathway inhibition in CRC and melanoma cells in vitro and in CRC cells in vivo. Furthermore, a R264 point mutation in PPP6C conferred loss of function in CRC cells, phenocopying the enhanced NF-κB activation and resistance to MAPK pathway inhibition observed for PPP6C deletion. These findings demonstrate that PP6 constrains the growth of KRAS- and BRAF-mutant cancer cells, implicates the PP6-NF-κB axis as a modulator of MAPK pathway output, and presents a rationale for cotargeting the NF-κB pathway in PPP6C-mutant cancer cells.
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Affiliation(s)
- Haibo Zhang
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Abigail Read
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Christophe Cataisson
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Howard H Yang
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Wei-Chun Lee
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Benjamin E Turk
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Stuart H Yuspa
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Ji Luo
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
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2
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Kondo A, Tanaka H, Rai S, Shima H, Matsumura I, Watanabe T. Depletion of Ppp6c in hematopoietic and vascular endothelial cells causes embryonic lethality and decreased hematopoietic potential. Exp Hematol 2024; 133:104205. [PMID: 38490577 DOI: 10.1016/j.exphem.2024.104205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 03/02/2024] [Accepted: 03/04/2024] [Indexed: 03/17/2024]
Abstract
Protein phosphatase 6 (PP6) is a serine/threonine (Ser/Thr) protein phosphatase, and its catalytic subunit is Ppp6c. PP6 forms the PP2A subfamily with PP2A and PP4. The diverse phenotypes observed following small interfering RNA (siRNA)-based knockdown of Ppp6c in cultured mammalian cells suggest that PP6 plays roles in cell growth and DNA repair. There is also evidence that PP6 regulates nuclear factor kappa B (NF-κB) signaling and mitogen-activated protein kinases and inactivates transforming growth factor-β-activated kinase 1 (TAK1). Loss of Ppp6c causes several abnormalities, including those of T cell and regulatory T cell function, neurogenesis, oogenesis, and spermatogenesis. PP2A has been reported to play an important role in erythropoiesis. However, the roles of PP6 in other hematopoietic cells have not been investigated. We generated Ppp6cfl/fl;Tie2-Cre (Ppp6cTKO) mice, in which Ppp6c was specifically deleted in hematopoietic and vascular endothelial cells. Ppp6cTKO mice displayed embryonic lethality. Ppp6c deficiency increased the number of dead cells and decreased the percentages of erythroid and monocytic cells during fetal hematopoiesis. By contrast, the number of Lin-Sca-1+c-Kit+ cells, which give rise to all hematopoietic cells, was slightly increased, but their colony-forming cell activity was markedly decreased. Ppp6c deficiency also increased phosphorylation of extracellular signal-regulated kinase 1/2 and c-Jun amino (N)-terminal kinase in fetal liver hematopoietic cells.
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Affiliation(s)
- Ayumi Kondo
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan
| | - Hirokazu Tanaka
- Department of Hematology and Rheumatology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
| | - Shinya Rai
- Department of Hematology and Rheumatology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
| | - Hiroshi Shima
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Natori, Miyagi, Japan
| | - Itaru Matsumura
- Department of Hematology and Rheumatology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan.
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3
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Ito M, Tanuma N, Kotani Y, Murai K, Kondo A, Sumiyoshi M, Shima H, Matsuda S, Watanabe T. Oncogenic K-Ras G12V cannot overcome proliferation failure caused by loss of Ppp6c in mouse embryonic fibroblasts. FEBS Open Bio 2024; 14:545-554. [PMID: 38318686 PMCID: PMC10988750 DOI: 10.1002/2211-5463.13775] [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: 09/28/2023] [Revised: 12/11/2023] [Accepted: 01/22/2024] [Indexed: 02/07/2024] Open
Abstract
Protein phosphatase 6 is a Ser/Thr protein phosphatase and its catalytic subunit is Ppp6c. Ppp6c is thought to be indispensable for proper growth of normal cells. On the other hand, loss of Ppp6c accelerates growth of oncogenic Ras-expressing cells. Although it has been studied in multiple contexts, the role(s) of Ppp6c in cell proliferation remains controversial. It is unclear how oncogenic K-Ras overcomes cell proliferation failure induced by Ppp6c deficiency; therefore, in this study, we attempted to shed light on how oncogenic K-Ras modulates tumor cell growth. Contrary to our expectations, loss of Ppp6c decreased proliferation, anchorage-independent growth in soft agar, and tumor formation of oncogenic Ras-expressing mouse embryonic fibroblasts (MEFs). These findings show that oncogenic K-RasG12V cannot overcome proliferation failure caused by loss of Ppp6c in MEFs.
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Affiliation(s)
- Mai Ito
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| | - Nobuhiro Tanuma
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
| | - Yui Kotani
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| | - Kokoro Murai
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| | - Ayumi Kondo
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| | - Mami Sumiyoshi
- Department of Cell Signaling, Institute of Biomedical ScienceKansai Medical UniversityHirakataJapan
| | - Hiroshi Shima
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
| | - Satoshi Matsuda
- Department of Cell Signaling, Institute of Biomedical ScienceKansai Medical UniversityHirakataJapan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
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4
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Matsuoka M, Sakai D, Shima H, Watanabe T. Neuron-specific loss of Ppp6c induces neonatal death and decreases the number of cortical neurons and interneurons. Biochem Biophys Res Commun 2024; 693:149353. [PMID: 38101002 DOI: 10.1016/j.bbrc.2023.149353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 12/17/2023]
Abstract
Protein phosphatase 6 (PP6) is a Ser/Thr protein phosphatase with the catalytic subunit Ppp6c. Recent cell-level studies have revealed that Ppp6c knockdown suppresses neurite outgrowth, suggesting that Ppp6c is involved in the development of the nervous system. We found that the function of PP6 in neurons is essential for mouse survival after birth, as all neural-stem-cell-specific KO (Ppp6cNKO) and neuron-specific KO mice died within 2 days of birth. By contrast, approximately 40 % of oligodendrocyte-specific KO mice died within 2 days of birth, whereas others survived until weaning or later, suggesting that the lethality of PP6 loss differs between neurons and oligodendrocytes. Furthermore, the fetal brain of Ppp6cNKO mice exhibited decreased numbers of neurons in layers V-VI and interneurons in layer I of the neocortex. These results suggest for the first time that Ppp6c is essential for neonatal survival and proper development of neurons and interneurons in the neocortex.
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Affiliation(s)
- Miki Matsuoka
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, 630-8506, Japan
| | - Daisuke Sakai
- Department of Biology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Hiroshi Shima
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, 981-1293, Japan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, 630-8506, Japan.
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Lyulcheva-Bennett E, Genomics England Research Consortium, Bennett D. A retrospective analysis of phosphatase catalytic subunit gene variants in patients with rare disorders identifies novel candidate neurodevelopmental disease genes. Front Cell Dev Biol 2023; 11:1107930. [PMID: 37056996 PMCID: PMC10086149 DOI: 10.3389/fcell.2023.1107930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 03/03/2023] [Indexed: 03/30/2023] Open
Abstract
Rare genetic disorders represent some of the most severe and life-limiting conditions that constitute a considerable burden on global healthcare systems and societies. Most individuals affected by rare disorders remain undiagnosed, highlighting the unmet need for improved disease gene discovery and novel variant interpretation. Aberrant (de) phosphorylation can have profound pathological consequences underpinning many disease processes. Numerous phosphatases and associated proteins have been identified as disease genes, with many more likely to have gone undiscovered thus far. To begin to address these issues, we have performed a systematic survey of de novo variants amongst 189 genes encoding phosphatase catalytic subunits found in rare disease patients recruited to the 100,000 Genomes Project (100 kGP), the largest national sequencing project of its kind in the United Kingdom. We found that 49% of phosphatases were found to carry de novo mutation(s) in this cohort. Only 25% of these phosphatases have been previously linked to genetic disorders. A gene-to-patient approach matching variants to phenotypic data identified 9 novel candidate rare-disease genes: PTPRD, PTPRG, PTPRT, PTPRU, PTPRZ1, MTMR3, GAK, TPTE2, PTPN18. As the number of patients undergoing whole genome sequencing increases and information sharing improves, we anticipate that reiterative analysis of genomic and phenotypic data will continue to identify candidate phosphatase disease genes for functional validation. This is the first step towards delineating the aetiology of rare genetic disorders associated with altered phosphatase function, leading to new biological insights and improved clinical outcomes for the affected individuals and their families.
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Affiliation(s)
| | | | - Daimark Bennett
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
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6
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Kokot T, Köhn M. Emerging insights into serine/threonine-specific phosphoprotein phosphatase function and selectivity. J Cell Sci 2022; 135:277104. [DOI: 10.1242/jcs.259618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
ABSTRACT
Protein phosphorylation on serine and threonine residues is a widely distributed post-translational modification on proteins that acts to regulate their function. Phosphoprotein phosphatases (PPPs) contribute significantly to a plethora of cellular functions through the accurate dephosphorylation of phosphorylated residues. Most PPPs accomplish their purpose through the formation of complex holoenzymes composed of a catalytic subunit with various regulatory subunits. PPP holoenzymes then bind and dephosphorylate substrates in a highly specific manner. Despite the high prevalence of PPPs and their important role for cellular function, their mechanisms of action in the cell are still not well understood. Nevertheless, substantial experimental advancements in (phospho-)proteomics, structural and computational biology have contributed significantly to a better understanding of PPP biology in recent years. This Review focuses on recent approaches and provides an overview of substantial new insights into the complex mechanism of PPP holoenzyme regulation and substrate selectivity.
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Affiliation(s)
- Thomas Kokot
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
| | - Maja Köhn
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
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7
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Deficiency of PPP6C protects TNF-induced necroptosis through activation of TAK1. Cell Death Dis 2022; 13:618. [PMID: 35842423 PMCID: PMC9288536 DOI: 10.1038/s41419-022-05076-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 01/21/2023]
Abstract
Necroptotic cell death is mediated by a super-molecular complex called necrosome which consists of receptor-interacting protein kinase 1 and 3 (RIPK1, RIPK3) and mixed-lineage kinase domain-like protein (MLKL). The role of these kinases has been extensively investigated in the regulation of necroptosis. However, whether the protein phosphatase is involved in necroptosis is still largely unknown. Here, we identified protein phosphatase 6 catalytic subunit (PPP6C) promotes TNF-induced necroptosis by genome-wide CRISPR/Cas9 library screening. We found that PPP6C deficiency protects cells from TNF-induced necroptosis in a phosphatase-activity-dependent manner. Mechanistically, PPP6C acts as a TGF-β activated kinase 1 (TAK1) phosphatase to inactivate its kinase activity. Deletion of PPP6C leads to hyperactivation of TAK1 and reduced RIPK1 kinase activity upon TNF stimulation. We further showed that heterozygous deletion of Ppp6c in mouse gastrointestinal tract alleviates necroptosis-related tissue injury and inflammation. Thus, our study identifies PPP6C as an important regulator of necroptosis and highlights a central role of phosphatase in the regulation of necroptosis-related diseases.
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8
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PPP6C, a serine-threonine phosphatase, regulates melanocyte differentiation and contributes to melanoma tumorigenesis through modulation of MITF activity. Sci Rep 2022; 12:5573. [PMID: 35368039 PMCID: PMC8976846 DOI: 10.1038/s41598-022-08936-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 03/07/2022] [Indexed: 12/28/2022] Open
Abstract
It is critical to understand the molecular mechanisms governing the regulation of MITF, a lineage specific transcription factor in melanocytes and an oncogene in melanoma. We identified PPP6C, a serine/threonine phosphatase, as a key regulator of MITF in melanoma. PPP6C is the only recurrently mutated serine/threonine phosphatase across all human cancers identified in sequencing studies and the recurrent R264C mutation occurs exclusively in melanoma. Using a zebrafish developmental model system, we demonstrate that PPP6C expression disrupts melanocyte differentiation. Melanocyte disruption was rescued by engineering phosphomimetic mutations at serine residues on MITF. We developed an in vivo MITF promoter assay in zebrafish and studied the effects of PPP6C(R264C) on regulating MITF promoter activity. Expression of PPP6C(R264C) cooperated with oncogenic NRAS(Q61K) to accelerate melanoma initiation in zebrafish, consistent with a gain of function alteration. Using a human melanoma cell line, we examined the requirement for PPP6C in proliferation and MITF expression. We show that genetic inactivation of PPP6C increases MITF and target gene expression, decreases sensitivity to BRAF inhibition, and increases phosphorylated MITF in a BRAF(V600E) mutant melanoma cell line. Our data suggests that PPP6C may be a relevant drug target in melanoma and proposes a mechanism for its action.
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9
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Kishimoto K, Kanazawa K, Nomura M, Tanaka T, Shigemoto-Kuroda T, Fukui K, Miura K, Kurosawa K, Kawai M, Kato H, Terasaki K, Sakamoto Y, Yamashita Y, Sato I, Tanuma N, Tamai K, Kitabayashi I, Matsuura K, Watanabe T, Yasuda J, Tsuji H, Shima H. Ppp6c deficiency accelerates K-ras G12D -induced tongue carcinogenesis. Cancer Med 2021; 10:4451-4464. [PMID: 34145991 PMCID: PMC8267137 DOI: 10.1002/cam4.3962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/09/2021] [Accepted: 04/19/2021] [Indexed: 12/18/2022] Open
Abstract
Background Effective treatments for cancer harboring mutant RAS are lacking. In Drosophila, it was reported that PP6 suppresses tumorigenicity of mutant RAS. However, the information how PP6 regulates oncogenic RAS in mammals is limited. Methods We examined the effects of PP6 gene (Ppp6c) deficiency on tongue tumor development in K (K‐rasG12D)‐ and KP (K‐rasG12D + Trp53‐deficient)‐inducible mice. Results Mice of K and KP genotypes developed squamous cell carcinoma in situ in the tongue approximately 2 weeks after the induction of Ppp6c deficiency and was euthanized due to 20% loss of body weight. Transcriptome analysis revealed significantly different gene expressions between tissues of Ppp6c‐deficient tongues and those of Ppp6c wild type, while Trp53 deficiency had a relatively smaller effect. We then analyzed genes commonly altered by Ppp6c deficiency, with or without Trp53 deficiency, and identified a group concentrated in KEGG database pathways defined as ‘Pathways in Cancer’ and ‘Cytokine‐cytokine receptor interaction’. We then evaluated signals downstream of oncogenic RAS and those regulated by PP6 substrates and found that in the presence of K‐rasG12D, Ppp6c deletion enhanced the activation of the ERK‐ELK1‐FOS, AKT‐4EBP1, and AKT‐FOXO‐CyclinD1 axes. Ppp6c deletion combined with K‐rasG12D also enhanced DNA double‐strand break (DSB) accumulation and activated NFκB signaling, upregulating IL‐1β, COX2, and TNF.
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Affiliation(s)
- Kazuhiro Kishimoto
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan.,Department of Head and Neck Surgery, Kanazawa Medical University, Kanazawa, Japan.,Department of Head and Neck Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Kosuke Kanazawa
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan.,Division of Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Miyuki Nomura
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Takuji Tanaka
- Research Center of Diagnostic Pathology, Gifu Municipal Hospital, Gifu, Japan
| | | | - Katsuya Fukui
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| | - Koh Miura
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Koreyuki Kurosawa
- Department of Plastic and Reconstructive Surgery, Tohoku University School of Medicine, Miyagi, Japan
| | - Masaaki Kawai
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Hiroyuki Kato
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Keiko Terasaki
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Yoshimi Sakamoto
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Yoji Yamashita
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Ikuro Sato
- Division of Pathology, Miyagi Cancer Center, Miyagi, Japan
| | - Nobuhiro Tanuma
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| | - Keiichi Tamai
- Division of Cancer Stem Cell, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Issay Kitabayashi
- Division of Hematological Malignancy, National Cancer Center Research Institute, Tokyo, Japan
| | - Kazuto Matsuura
- Department of Head and Neck Surgery, National Cancer Center Hospital East, Chiba, Japan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan
| | - Jun Yasuda
- Division of Molecular and Cellular Oncology, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Hiroyuki Tsuji
- Department of Head and Neck Surgery, Kanazawa Medical University, Kanazawa, Japan
| | - Hiroshi Shima
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
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Fujiwara N, Shibutani S, Ohama T, Sato K. Protein phosphatase 6 dissociates the Beclin 1/Vps34 complex and inhibits autophagy. Biochem Biophys Res Commun 2021; 552:191-195. [PMID: 33751937 DOI: 10.1016/j.bbrc.2021.02.136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
Autophagy is an evolutionarily conserved intracellular degradation system and is regulated by various signaling pathways including the Beclin 1/Vacuolar protein sorting 34 (Vps34) complex. Protein phosphatase 6 (PP6) is an essential serine/threonine phosphatase that regulates various biological processes. Recently, we found that PP6 protein is degraded by p62-dependent selective autophagy. In this study, we show that PP6 conversely inhibits autophagy. PP6 associate with the C-terminal region of Beclin 1, which is close to the binding region of Vps34. The protein levels of PP6 affect Beclin 1/Vps34 complex formation and phosphatase activity of PP6 is not involved in this. We also show that chemically induced PP6/Beclin 1 association leads to Vps34 dissociation from Beclin 1. Overall, our data reveal a novel regulatory mechanism for autophagy by PP6.
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Affiliation(s)
- Nobuyuki Fujiwara
- Laboratory of Veterinary Pharmacology, 753-8515, Yamaguchi, Japan; Laboratory of Drug Discovery and Pharmacology, Faculty of Veterinary Medicine, Okayama University of Science, 794-8555, Ehime, Japan
| | - Shusaku Shibutani
- Laboratory of Veterinary Hygiene, Yamaguchi University, 753-8515, Yamaguchi, Japan
| | - Takashi Ohama
- Laboratory of Veterinary Pharmacology, 753-8515, Yamaguchi, Japan.
| | - Koichi Sato
- Laboratory of Veterinary Pharmacology, 753-8515, Yamaguchi, Japan
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11
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Kanazawa K, Kishimoto K, Nomura M, Kurosawa K, Kato H, Inoue Y, Miura K, Fukui K, Yamashita Y, Sato I, Tsuji H, Watanabe T, Tanaka T, Yasuda J, Tanuma N, Shima H. Ppp6c haploinsufficiency accelerates UV-induced BRAF(V600E)-initiated melanomagenesis. Cancer Sci 2021; 112:2233-2244. [PMID: 33743547 PMCID: PMC8177767 DOI: 10.1111/cas.14895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 03/10/2021] [Accepted: 03/17/2021] [Indexed: 02/06/2023] Open
Abstract
According to TCGA database, mutations in PPP6C (encoding phosphatase PP6) are found in c. 10% of tumors from melanoma patients, in which they coexist with BRAF and NRAS mutations. To assess PP6 function in melanoma carcinogenesis, we generated mice in which we could specifically induce BRAF(V600E) expression and delete Ppp6c in melanocytes. In these mice, melanoma susceptibility following UVB irradiation exhibited the following pattern: Ppp6c semi‐deficient (heterozygous) > Ppp6c wild‐type > Ppp6c‐deficient (homozygous) tumor types. Next‐generation sequencing of Ppp6c heterozygous and wild‐type melanoma tumors revealed that all harbored Trp53 mutations. However, Ppp6c heterozygous tumors showed a higher Signature 1 (mitotic/mitotic clock) mutation index compared with Ppp6c wild‐type tumors, suggesting increased cell division. Analysis of cell lines derived from either Ppp6c heterozygous or wild‐type melanoma tissues showed that both formed tumors in nude mice, but Ppp6c heterozygous tumors grew faster compared with those from the wild‐type line. Ppp6c knockdown via siRNA in the Ppp6c heterozygous line promoted the accumulation of genomic damage and enhanced apoptosis relative to siRNA controls. We conclude that in the presence of BRAF(V600E) expression and UV‐induced Trp53 mutation, Ppp6c haploinsufficiency promotes tumorigenesis.
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Affiliation(s)
- Kosuke Kanazawa
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Surgery, Miyagi Cancer Center, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| | - Kazuhiro Kishimoto
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan.,Department of Head and Neck Surgery, Kanazawa Medical University, Ishikawa, Japan
| | - Miyuki Nomura
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Koreyuki Kurosawa
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Department of Plastic and Reconstructive Surgery, Tohoku University School of Medicine, Miyagi, Japan
| | - Hiroyuki Kato
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Yui Inoue
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Koh Miura
- Division of Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Katsuya Fukui
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| | - Yoji Yamashita
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Ikuro Sato
- Division of Pathology, Miyagi Cancer Center, Miyagi, Japan
| | - Hiroyuki Tsuji
- Department of Head and Neck Surgery, Kanazawa Medical University, Ishikawa, Japan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and Sciences Nara Women's University, Nara, Japan
| | - Takuji Tanaka
- Research Center of Diagnostic Pathology, Gifu Municipal Hospital, Gifu, Japan
| | - Jun Yasuda
- Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan.,Cancer Genome Center, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Tohoku Medical Megabank Organization, Tohoku University, Miyagi, Japan
| | - Nobuhiro Tanuma
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| | - Hiroshi Shima
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
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12
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Rivard RS, Morris JM, Youngman MJ. The PP2A/4/6 subfamily of phosphoprotein phosphatases regulates DAF-16 and confers resistance to environmental stress in postreproductive adult C. elegans. PLoS One 2020; 15:e0229812. [PMID: 33315870 PMCID: PMC7735605 DOI: 10.1371/journal.pone.0229812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 11/13/2020] [Indexed: 11/28/2022] Open
Abstract
Insulin and insulin-like growth factors are longevity determinants that negatively regulate Forkhead box class O (FoxO) transcription factors. In C. elegans mutations that constitutively activate DAF-16, the ortholog of mammalian FoxO3a, extend lifespan by two-fold. While environmental insults induce DAF-16 activity in younger animals, it also becomes activated in an age-dependent manner in the absence of stress, modulating gene expression well into late adulthood. The mechanism by which DAF-16 activity is regulated during aging has not been defined. Since phosphorylation of DAF-16 generally leads to its inhibition, we asked whether phosphatases might be necessary for its increased transcriptional activity in adult C. elegans. We focused on the PP2A/4/6 subfamily of phosphoprotein phosphatases, members of which had been implicated to regulate DAF-16 under low insulin signaling conditions but had not been investigated during aging in wildtype animals. Using reverse genetics, we functionally characterized all C. elegans orthologs of human catalytic, regulatory, and scaffolding subunits of PP2A/4/6 holoenzymes in postreproductive adults. We found that PP2A complex constituents PAA-1 and PPTR-1 regulate DAF-16 transcriptional activity during aging and that they cooperate with the catalytic subunit LET-92 to protect adult animals from ultraviolet radiation. PP4 complex members PPH-4.1/4.2, and SMK-1 also appear to regulate DAF-16 in an age-dependent manner, and together with PPFR-2 they contribute to innate immunity. Interestingly, SUR-6 but no other subunit of the PP2A complex was necessary for the survival of pathogen-infected animals. Finally, we found that PP6 complex constituents PPH-6 and SAPS-1 contribute to host defense during aging, apparently without affecting DAF-16 transcriptional activity. Our studies indicate that a set of PP2A/4/6 complexes protect adult C. elegans from environmental stress, thus preserving healthspan. Therefore, along with their functions in cell division and development, the PP2A/4/6 phosphatases also appear to play critical roles later in life.
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Affiliation(s)
- Rebecca S. Rivard
- Department of Biology, Villanova University, Villanova, PA, United States of America
| | - Julia M. Morris
- Department of Biology, Villanova University, Villanova, PA, United States of America
| | - Matthew J. Youngman
- Department of Biology, Villanova University, Villanova, PA, United States of America
- * E-mail:
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13
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Protein kinase CK2 phosphorylation of SAPS3 subunit increases PP6 phosphatase activity with Aurora A kinase. Biochem J 2020; 477:431-444. [PMID: 31904830 DOI: 10.1042/bcj20190740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/04/2019] [Accepted: 01/06/2020] [Indexed: 12/11/2022]
Abstract
Protein Ser/Thr phosphatase-6 (PP6) regulates pathways for activation of NF-kB, YAP1 and Aurora A kinase (AURKA). PP6 is a heterotrimer comprised of a catalytic subunit, one of three different SAPS subunits and one of three different ankyrin-repeat ANKRD subunits. Here, we show FLAG-PP6C expressed in cells preferentially binds endogenous SAPS3, and the complex is active with the chemical substrate DiFMUP. SAPS3 has multiple acidic sequence motifs recognized by protein kinase CK2 (CK2) and SAPS3 is phosphorylated by purified CK2, without affecting its associated PP6 phosphatase activity. However, HA3-SAPS3-PP6 phosphatase activity using pT288 AURKA as substrate is significantly increased by phosphorylation with CK2. The substitution of Ala in nine putative phosphorylation sites in SAPS3 was required to prevent CK2 activation of the phosphatase. Different CK2 chemical inhibitors equally increased phosphorylation of endogenous AURKA in living cells, consistent with reduction in PP6 activity. CRISPR/Cas9 deletion or siRNA knockdown of SAPS3 resulted in highly activated endogenous AURKA, and a high proportion of cells with abnormal nuclei. Activation of PP6 by CK2 can form a feedback loop with bistable changes in substrates.
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14
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Li M, Shu HB. Dephosphorylation of cGAS by PPP6C impairs its substrate binding activity and innate antiviral response. Protein Cell 2020; 11:584-599. [PMID: 32474700 PMCID: PMC7381519 DOI: 10.1007/s13238-020-00729-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022] Open
Abstract
The cyclic GMP-AMP (cGAMP) synthase (cGAS) plays a critical role in host defense by sensing cytosolic DNA derived from microbial pathogens or mis-located cellular DNA. Upon DNA binding, cGAS utilizes GTP and ATP as substrates to synthesize cGAMP, leading to MITA-mediated innate immune response. In this study, we identified the phosphatase PPP6C as a negative regulator of cGAS-mediated innate immune response. PPP6C is constitutively associated with cGAS in un-stimulated cells. DNA virus infection causes rapid disassociation of PPP6C from cGAS, resulting in phosphorylation of human cGAS S435 or mouse cGAS S420 in its catalytic pocket. Mutation of this serine residue of cGAS impairs its ability to synthesize cGAMP upon DNA virus infection. In vitro experiments indicate that S420-phosphorylated mcGAS has higher affinity to GTP and enzymatic activity. PPP6C-deficiency promotes innate immune response to DNA virus in various cells. Our findings suggest that PPP6C-mediated dephosphorylation of a catalytic pocket serine residue of cGAS impairs its substrate binding activity and innate immune response, which provides a mechanism for keeping the DNA sensor cGAS inactive in the absence of infection to avoid autoimmune response.
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Affiliation(s)
- Mi Li
- Department of Infectious Diseases, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Hong-Bing Shu
- Department of Infectious Diseases, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, College of Life Sciences, Wuhan University, Wuhan, 430071, China.
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15
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Guneykaya D, Ivanov A, Hernandez DP, Haage V, Wojtas B, Meyer N, Maricos M, Jordan P, Buonfiglioli A, Gielniewski B, Ochocka N, Cömert C, Friedrich C, Artiles LS, Kaminska B, Mertins P, Beule D, Kettenmann H, Wolf SA. Transcriptional and Translational Differences of Microglia from Male and Female Brains. Cell Rep 2019; 24:2773-2783.e6. [PMID: 30184509 DOI: 10.1016/j.celrep.2018.08.001] [Citation(s) in RCA: 272] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 04/19/2018] [Accepted: 07/31/2018] [Indexed: 02/07/2023] Open
Abstract
Sex differences in brain structure and function are of substantial scientific interest because of sex-related susceptibility to psychiatric and neurological disorders. Neuroinflammation is a common denominator of many of these diseases, and thus microglia, as the brain's immunocompetent cells, have come into focus in sex-specific studies. Here, we show differences in the structure, function, and transcriptomic and proteomic profiles in microglia freshly isolated from male and female mouse brains. We show that male microglia are more frequent in specific brain areas, have a higher antigen-presenting capacity, and appear to have a higher potential to respond to stimuli such as ATP, reflected in higher baseline outward and inward currents and higher protein expression of purinergic receptors. Altogether, we provide a comprehensive resource to generate and validate hypotheses regarding brain sex differences.
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Affiliation(s)
- Dilansu Guneykaya
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Andranik Ivanov
- Core Unit Bioinformatics, Berlin Institute of Health, Berlin, Germany; Charité-Universitaetsmedizin, Berlin, Germany
| | - Daniel Perez Hernandez
- Proteomics Platform, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Berlin Institute of Health, 13125 Berlin, Germany
| | - Verena Haage
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Bartosz Wojtas
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Niklas Meyer
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Meron Maricos
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Philipp Jordan
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Alice Buonfiglioli
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany; Institute of Cell Biology and Neurobiology, Charité-Universitaetsmedizin, Berlin, Germany
| | - Bartlomiej Gielniewski
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Natalia Ochocka
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Cagla Cömert
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Corinna Friedrich
- Proteomics Platform, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Lorena Suarez Artiles
- Proteomics Platform, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Bozena Kaminska
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Philipp Mertins
- Proteomics Platform, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Berlin Institute of Health, 13125 Berlin, Germany
| | - Dieter Beule
- Core Unit Bioinformatics, Berlin Institute of Health, Berlin, Germany; Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Helmut Kettenmann
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Susanne A Wolf
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany; Department of Ophthalmology, Charité-Universitaetsmedizin, Augustenburger Platz 1, 13353, Berlin, Germany.
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16
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Dziegielewski J, Bońkowska MA, Poniecka EA, Heo J, Du K, Crittenden RB, Bender TP, Brautigan DL, Larner JM. Deletion of the SAPS1 subunit of protein phosphatase 6 in mice increases radiosensitivity and impairs the cellular DNA damage response. DNA Repair (Amst) 2019; 85:102737. [PMID: 31751917 DOI: 10.1016/j.dnarep.2019.102737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/17/2019] [Accepted: 10/15/2019] [Indexed: 12/24/2022]
Abstract
Cellular responses to DNA damage include activation of DNA-dependent protein kinase (DNA-PK) through, among others, the serine/threonine protein phosphatase 6 (PP6). We previously showed that recognition of DNA-PKcs is mediated by the SAPS1 PP6 regulatory subunit. Here, we report and characterize a SAPS1 null mouse and investigate the effects of deletion on DNA damage signaling and repair. Strikingly, neither SAPS1-null animals nor cells derived from them show gross defects, unless subjected to DNA damage by radiation or chemical agents. The overall survival of SAPS1-null animals following whole body irradiation is significantly shortened as compared to wild-type mice, and the clonogenic survival of null cells subjected to ionizing radiation is reduced. The dephosphorylation of DNA damage/repair markers, such as γH2AX, p53 and Kap1, is diminished in SAPS1-null cells as compared to wild-type controls. Our results demonstrate that loss of SAPS1 confers sensitivity to DNA damage and confirms previously reported cellular phenotypes of SAPS1 knock-down in human glioma cells. The results support a role for PP6 regulatory subunit SAPS1 in DNA damage responses, and offer a novel target for sensitization to enhance current tumor therapies, with a potential for limited deleterious side effects.
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Affiliation(s)
- Jaroslaw Dziegielewski
- Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Magdalena A Bońkowska
- Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Ewa A Poniecka
- Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Jinho Heo
- Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Kangping Du
- Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Rowena B Crittenden
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Beirne B. Carter Center for Immunology Research, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Timothy P Bender
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Beirne B. Carter Center for Immunology Research, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - David L Brautigan
- Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - James M Larner
- Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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17
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Multiple Functions of the Essential Gene PpV in Drosophila Early Development. G3-GENES GENOMES GENETICS 2019; 9:3583-3593. [PMID: 31484673 PMCID: PMC6829155 DOI: 10.1534/g3.119.400662] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein phosphatase V (PpV) encodes the Drosophila homolog of the evolutionarily conserved Protein Phosphatase 6 (PP6). The physiological and developmental functions of PpV/PP6 have not been well characterized due to lack of a genetically defined mutant. Here, we identified a PpV non-sense mutation and describe multiple mutant phenotypes in oogenesis and early embryogenesis. Specifically, we found that the defects in chromosome segregation during nuclear cycles are related to AuroraA function, which is consistent with the interaction of PP6 and AuroraA in mammalian cells. Surprisingly, we also identified a PpV function specifically in blastoderm cell cycle but not in cell proliferation in the follicle epithelium or larval wing imaginal discs. Embryos from PpV germline clones frequently undergo an extra nuclear division cycle. By epistasis analysis, we found that PpV functions in parallel with tribbles, but independently of auroraA for the remodeling of the nuclear cycles. Taken together, this study reports novel developmental functions of PpV and provides a framework for further genetic analysis under physiological conditions.
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18
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Yamindago A, Lee N, Woo S, Yum S. Transcriptomic profiling of Hydra magnipapillata after exposure to naproxen. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2019; 71:103215. [PMID: 31301532 DOI: 10.1016/j.etap.2019.103215] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/12/2019] [Accepted: 06/23/2019] [Indexed: 06/10/2023]
Abstract
The extensive use in humans and animals of nonsteroidal anti-inflammatory drugs (NSAIDs) increases their possible impact on aquatic organisms. In the present study, we investigated acute toxicity, morphological responses, and potential physiological and metabolic impacts of naproxen exposure on Hydra magnipapillata. The median lethal concentrations (LC50) of naproxen in H. magnipapillata were 51.999 mg/L, 44.935 mg/L, and 42.500 mg/L after exposure for 24, 48, and 72 h, respectively. Morphological observation of the exposed Hydra showed that 40 mg/L naproxen stimulated the contraction of body column and tentacles after 24 h. A KEGG pathway analysis of the genes differentially expressed in the Hydra after exposure to naproxen for 6, 24, or 48 h demonstrated various cellular and metabolic effects, including protein processing in the endoplasmic reticulum, Wnt signaling, and tryptophan metabolism. These results suggest that exposure to naproxen affects the genetic material, inflammatory processes, and metabolic processes of aquatic organisms.
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Affiliation(s)
- Ade Yamindago
- Ecological Risk Research Division, Korea Institute of Ocean Science and Technology (KIOST), Geoje, 53201, Republic of Korea; The Faculty of Applied Ocean Science, University of Science and Technology (UST), Geoje, 53201, Republic of Korea; Faculty of Fisheries and Marine Science, Brawijaya University, Malang, 65145, Indonesia
| | - Nayun Lee
- Ecological Risk Research Division, Korea Institute of Ocean Science and Technology (KIOST), Geoje, 53201, Republic of Korea
| | - Seonock Woo
- Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology (KIOST), Busan, 49111, Republic of Korea
| | - Seungshic Yum
- Ecological Risk Research Division, Korea Institute of Ocean Science and Technology (KIOST), Geoje, 53201, Republic of Korea; The Faculty of Applied Ocean Science, University of Science and Technology (UST), Geoje, 53201, Republic of Korea.
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19
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Ohama T. The multiple functions of protein phosphatase 6. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:74-82. [DOI: 10.1016/j.bbamcr.2018.07.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/21/2018] [Accepted: 07/18/2018] [Indexed: 12/26/2022]
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20
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PpV, acting via the JNK pathway, represses apoptosis during normal development of Drosophila wing. Apoptosis 2018; 23:554-562. [DOI: 10.1007/s10495-018-1479-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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21
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Kurosawa K, Inoue Y, Kakugawa Y, Yamashita Y, Kanazawa K, Kishimoto K, Nomura M, Momoi Y, Sato I, Chiba N, Suzuki M, Ogoh H, Yamada H, Miura K, Watanabe T, Tanuma N, Tachi M, Shima H. Loss of protein phosphatase 6 in mouse keratinocytes enhances K-ras G12D -driven tumor promotion. Cancer Sci 2018; 109:2178-2187. [PMID: 29758119 PMCID: PMC6029815 DOI: 10.1111/cas.13638] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/03/2018] [Accepted: 05/08/2018] [Indexed: 01/17/2023] Open
Abstract
Here, we address the function of protein phosphatase 6 (PP6) loss on K‐ras‐initiated tumorigenesis in keratinocytes. To do so, we developed tamoxifen‐inducible double mutant (K‐rasG12D‐expressing and Ppp6c‐deficient) mice in which K‐rasG12D expression is driven by the cytokeratin 14 (K14) promoter. Doubly‐mutant mice showed early onset tumor formation in lips, nipples, external genitalia, anus and palms, and had to be killed by 3 weeks after induction by tamoxifen, while comparably‐treated K‐rasG12D‐expressing mice did not. H&E‐staining of lip tumors before euthanasia revealed that all were papillomas, some containing focal squamous cell carcinomas. Immunohistochemical analysis of lips of doubly‐mutant vs K‐rasG12D mice revealed that cell proliferation and cell size increased approximately 2‐fold relative to K‐rasG12D‐expressing mutants, and epidermal thickness of lip tissue greatly increased relative to that seen in K‐rasG12D‐only mice. Moreover, AKT phosphorylation increased in K‐rasG12D‐expressing/Ppp6c‐deficient cells, as did phosphorylation of the downstream effectors 4EBP1, S6 and GSK3, suggesting that protein synthesis and survival signals are enhanced in lip tissues of doubly‐mutant mice. Finally, increased numbers of K14‐positive cells were present in the suprabasal layer of doubly‐mutant mice, indicating abnormal keratinocyte differentiation, and γH2AX‐positive cells accumulated, indicating perturbed DNA repair. Taken together, Ppp6c deficiency enhances K‐rasG12D‐dependent tumor promotion.
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Affiliation(s)
- Koreyuki Kurosawa
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Department of Plastic and Reconstructive Surgery, Tohoku University Hospital, Miyagi, Japan
| | - Yui Inoue
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Yoichiro Kakugawa
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Yoji Yamashita
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Kosuke Kanazawa
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Kazuhiro Kishimoto
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Miyuki Nomura
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Yuki Momoi
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Ikuro Sato
- Division of Pathology, Miyagi Cancer Center, Miyagi, Japan
| | - Natsuko Chiba
- Department of Cancer Biology, Institute of Development, Aging and Cancer, Tohoku University, Miyagi, Japan
| | - Mai Suzuki
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan
| | - Honami Ogoh
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan
| | - Hidekazu Yamada
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Koh Miura
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan
| | - Nobuhiro Tanuma
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| | - Masahiro Tachi
- Department of Plastic and Reconstructive Surgery, Tohoku University Hospital, Miyagi, Japan
| | - Hiroshi Shima
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
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22
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Gobikrushanth M, Purfield DC, Colazo MG, Butler ST, Wang Z, Ambrose DJ. The relationship between serum anti-Müllerian hormone concentrations and fertility, and genome-wide associations for anti-Müllerian hormone in Holstein cows. J Dairy Sci 2018; 101:7563-7574. [PMID: 29729909 DOI: 10.3168/jds.2017-13940] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 03/21/2018] [Indexed: 12/21/2022]
Abstract
The objectives of this study were to (1) evaluate factors associated with variation in circulating anti-Müllerian hormone (AMH) concentrations, (2) establish an optimum AMH threshold predictive of pregnancy to first artificial insemination (P/AI), (3) examine the relationship between AMH and fertility (P/AI, pregnancy loss between 30 and 60 d after artificial insemination, and pregnancy risk up to 250 d postpartum), and (4) identify quantitative trait loci associated with phenotypic variation of AMH concentrations in dairy cows. Serum AMH concentrations (pg/mL) were determined at 7 ± 2.4 d postpartum in 647 lactating Holstein cows (213 primiparous, 434 multiparous) from 1 research and 6 commercial dairy herds in Alberta, Canada. Of these, 589 cows were genotyped on the 26K Bovine BeadChip (Neogen Inc., Lincoln, NE) and subsequently imputed to the Illumina Bovine High Density BeadChip (Illumina, San Diego, CA) for genome-wide association analysis for variation in serum AMH concentrations. Factors associated with variation in serum AMH concentrations and the relationship between categories of AMH and aforementioned fertility outcomes were evaluated only in a subset of 460 cows that had a complete data set available. The overall mean (±standard error of the mean), median, minimum, and maximum AMH concentrations were 191.1 ± 6.3, 151.7, 13.9, and 1,879.0 pg/mL, respectively. The AMH concentrations were not associated with herd, precalving body condition score, postpartum week, and season of sampling; the lactation number, however, had a quadratic relationship with serum AMH concentrations (116.2, 204.9 204.5, and 157.9 pg/mL for first, second, third, and ≥fourth lactation, respectively). The optimum AMH threshold predictive of P/AI could not be established because the receiver operating characteristic curve analysis model was nonsignificant. Categories of AMH [low (<83.0 pg/mL; n = 92), intermediate (≥83.0 to ≤285.0 pg/mL; n = 276), and high (>285.0 pg/mL; n = 92) based on lowest 20%, intermediate 60%, and highest 20% serum AMH) had no associations with P/AI (34, 43, and 40%), pregnancy loss between 30 and 60 d after artificial insemination (20, 12, and 8%), or pregnancy risk up to 250 d postpartum. One candidate gene associated with AMH production [AMH gene on Bos taurus autosome (BTA) 7] and 4 candidate genes related to embryo development (SCAI and PPP6C genes on BTA11 and FGF18 and EEF2K genes on BTA20 and BTA25, respectively) were in linkage disequilibrium with single nucleotide polymorphisms associated with phenotypic variation in serum AMH in dairy cows.
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Affiliation(s)
- M Gobikrushanth
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5; Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland, P61 C996
| | - D C Purfield
- Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland, P61 C996
| | - M G Colazo
- Livestock Research and Extension Branch, Alberta Agriculture and Forestry, Edmonton, AB, Canada T6H 5T6
| | - S T Butler
- Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland, P61 C996
| | - Z Wang
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5
| | - D J Ambrose
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5; Livestock Research and Extension Branch, Alberta Agriculture and Forestry, Edmonton, AB, Canada T6H 5T6.
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23
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Functions of protein phosphatase-6 in NF-κB signaling and in lymphocytes. Biochem Soc Trans 2017; 45:693-701. [PMID: 28620030 PMCID: PMC5473023 DOI: 10.1042/bst20160169] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/01/2017] [Accepted: 03/08/2017] [Indexed: 12/17/2022]
Abstract
Protein phosphatase-6 (PP6) is a member of the PPP family of Ser/Thr phosphatases involved in intracellular signaling. PP6 is conserved among all eukaryotes, and genetics in model organisms indicates it has non-redundant functions relative to other PPP phosphatases. PP6 functions in association with conserved SAPS subunits and, in vertebrate species, forms heterotrimers with Ankrd subunits. Multiple studies have demonstrated how PP6 exerts negative control at different steps of nuclear factor kappaB signaling. Expression of PP6 catalytic subunit and the PPP6R1 subunit is especially high in hematopoietic cells and lymphoid tissues. Recent efforts at conditionally knocking out genes for PP6c or PP6R1 (SAPS1) have revealed distinctive effects on development of and signaling in lymphocytes.
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