1
|
Wu D, Van der Hoeven G, Claes Z, Van Eynde A, Bollen M. DNA damage-induced allosteric activation of protein phosphatase PP1:NIPP1 through Src kinase-induced circularization of NIPP1. FEBS J 2024; 291:2615-2635. [PMID: 38303113 DOI: 10.1111/febs.17064] [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: 07/03/2023] [Revised: 12/06/2023] [Accepted: 12/28/2023] [Indexed: 02/03/2024]
Abstract
Protein phosphatase-1 (PP1) complexed to nuclear inhibitor of PP1 (NIPP1) limits DNA repair through dephosphorylation of NIPP1-recruited substrates. However, the PP1:NIPP1 holoenzyme is completely inactive under basal conditions, hinting at a DNA damage-regulated activation mechanism. Here, we report that DNA damage caused the activation of PP1:NIPP1 after a time delay of several hours through phosphorylation of NIPP1 at the C-terminal tyrosine 335 (Y335) by a Src-family kinase. PP1:NIPP1 activation partially resulted from the dissociation of the C terminus of NIPP1 from the active site of PP1. In addition, the released Y335-phosphorylated C terminus interacted with the N terminus of NIPP1 to enhance substrate recruitment by the flanking forkhead-associated (FHA) domain. Constitutive activation of PP1:NIPP1 by knock-in of a phospho-mimicking (Y335E) NIPP1 mutant led to the hypo-phosphorylation of FHA ligands and an accumulation of DNA double-strand breaks. Our data indicate that PP1:NIPP1 activation through circularization of NIPP1 is a late response to DNA damage that contributes to the timely recovery from damage repair.
Collapse
Affiliation(s)
- Dan Wu
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Gerd Van der Hoeven
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Zander Claes
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Aleyde Van Eynde
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Mathieu Bollen
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| |
Collapse
|
2
|
Jonkhout MCM, Vanhessche T, Ferreira M, Verbinnen I, Withof F, Van der Hoeven G, Szekér K, Azhir Z, Lien WH, Van Eynde A, Bollen M. Embryonic NIPP1 Depletion in Keratinocytes Triggers a Cell Cycle Arrest and Premature Senescence in Adult Mice. J Invest Dermatol 2024:S0022-202X(24)00167-2. [PMID: 38431220 DOI: 10.1016/j.jid.2024.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 01/24/2024] [Accepted: 02/09/2024] [Indexed: 03/05/2024]
Abstract
NIPP1 is a ubiquitously expressed regulatory subunit of PP1. Its embryonic deletion in keratinocytes causes chronic sterile skin inflammation, epidermal hyperproliferation, and resistance to mutagens in adult mice. To explore the primary effects of NIPP1 deletion, we first examined hair cycle progression of NIPP1 skin knockouts (SKOs). The entry of the first hair cycle in the SKOs was delayed owing to prolonged quiescence of hair follicle stem cells. In contrast, the entry of the second hair cycle in the SKOs was advanced as a result of precocious activation of hair follicle stem cells. The epidermis of SKOs progressively accumulated senescent cells, and this cell-fate switch was accelerated by DNA damage. Primary keratinocytes from SKO neonates and human NIPP1-depleted HaCaT keratinocytes failed to proliferate and showed an increase in the expression of cell cycle inhibitors (p21, p16/Ink4a, and/or p19/Arf) and senescence-associated-secretory-phenotype factors as well as in DNA damage (γH2AX and 53BP1). Our data demonstrate that the primary effect of NIPP1 deletion in keratinocytes is a cell cycle arrest and premature senescence that gradually progresse to chronic senescence and likely contribute to the decreased sensitivity of SKOs to mutagens.
Collapse
Affiliation(s)
- Marloes C M Jonkhout
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Tijs Vanhessche
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Mónica Ferreira
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Iris Verbinnen
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Fabienne Withof
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Gerd Van der Hoeven
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Kathelijne Szekér
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Zahra Azhir
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Wen-Hui Lien
- de Duve Institute, Faculty of Medicine, Université catholique de Louvain, Brussels, Belgium
| | - Aleyde Van Eynde
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium.
| | - Mathieu Bollen
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| |
Collapse
|
3
|
Kieft R, Zhang Y, Yan H, Schmitz RJ, Sabatini R. Knockout of protein phosphatase 1 in Leishmania major reveals its role during RNA polymerase II transcription termination. Nucleic Acids Res 2023; 51:6208-6226. [PMID: 37194692 PMCID: PMC10325913 DOI: 10.1093/nar/gkad394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/26/2023] [Accepted: 05/04/2023] [Indexed: 05/18/2023] Open
Abstract
The genomes of kinetoplastids are organized into polycistronic transcription units that are flanked by a modified DNA base (base J, beta-D-glucosyl-hydroxymethyluracil). Previous work established a role of base J in promoting RNA polymerase II (Pol II) termination in Leishmania major and Trypanosoma brucei. We recently identified a PJW/PP1 complex in Leishmania containing a J-binding protein (JBP3), PP1 phosphatase 1, PP1 interactive-regulatory protein (PNUTS) and Wdr82. Analyses suggested the complex regulates transcription termination by recruitment to termination sites via JBP3-base J interactions and dephosphorylation of proteins, including Pol II, by PP1. However, we never addressed the role of PP1, the sole catalytic component, in Pol II transcription termination. We now demonstrate that deletion of the PP1 component of the PJW/PP1 complex in L. major, PP1-8e, leads to readthrough transcription at the 3'-end of polycistronic gene arrays. We show PP1-8e has in vitro phosphatase activity that is lost upon mutation of a key catalytic residue and associates with PNUTS via the conserved RVxF motif. Additionally, purified PJW complex with associated PP1-8e, but not complex lacking PP1-8e, led to dephosphorylation of Pol II, suggesting a direct role of PNUTS/PP1 holoenzymes in regulating transcription termination via dephosphorylating Pol II in the nucleus.
Collapse
Affiliation(s)
- Rudo Kieft
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA30602, USA
| | - Yang Zhang
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA30602, USA
| | - Haidong Yan
- Department of Genetics, University of Georgia, Athens, GA30602, USA
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, GA30602, USA
| | - Robert Sabatini
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA30602, USA
| |
Collapse
|
4
|
Kow RL, Black AH, Henderson BP, Kraemer BC. Sut-6/NIPP1 modulates tau toxicity. Hum Mol Genet 2023; 32:2292-2306. [PMID: 37000013 PMCID: PMC10321383 DOI: 10.1093/hmg/ddad049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 03/04/2023] [Accepted: 03/27/2023] [Indexed: 04/01/2023] Open
Abstract
Neurodegenerative diseases exhibiting the pathological accumulation of tau such as Alzheimer's disease and related disorders still have no disease-modifying treatments and the molecular mechanisms of neurodegeneration remain unclear. To discover additional suppressor of tauopathy (sut) genes that mediate or modulate the toxicity of pathological tau, we performed a classical genetic screen using a tau transgenic Caenorhabditis elegans model. From this screen, we identified the suppressing mutation W292X in sut-6, the C. elegans homolog of human NIPP1, which truncates the C-terminal RNA-binding domain. Using CRISPR-based genome editing approaches, we generated null and additional C-terminally truncated alleles in sut-6 and found that loss of sut-6 or sut-6(W292X) suppresses tau-induced behavioral locomotor deficits, tau protein accumulation and neuron loss. The sut-6(W292X) mutation showed stronger and semi-dominant suppression of tau toxicity while sut-6 deletion acted recessively. Neuronal overexpression of SUT-6 protein did not significantly alter tau toxicity, but neuronal overexpression of SUT-6 W292X mutant protein reduced tau-mediated deficits. Epistasis studies showed tauopathy suppression by sut-6 occurs independent of other known nuclear speckle-localized suppressors of tau such as sut-2, aly-1/aly-3 and spop-1. In summary, we have shown that sut-6/NIPP1 modulates tau toxicity and found a dominant mutation in the RNA-binding domain of sut-6 which strongly suppresses tau toxicity. This suggests that altering RNA-related functions of SUT-6/NIPP1 instead of complete loss of SUT-6/NIPP1 will provide the strongest suppression of tau.
Collapse
Affiliation(s)
- R L Kow
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - A H Black
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - B P Henderson
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - B C Kraemer
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
- Department of Psychiatry and Behavioral Sciences
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| |
Collapse
|
5
|
Wang Q. The role of forkhead-associated (FHA)-domain proteins in plant biology. PLANT MOLECULAR BIOLOGY 2023; 111:455-472. [PMID: 36849846 DOI: 10.1007/s11103-023-01338-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
The forkhead-associated (FHA) domain, a well-characterized small protein module that mediates protein-protein interactions by targeting motifs containing phosphothreonine, is present in many regulatory molecules like protein kinase, phosphatases, transcription factors, and other functional proteins. FHA-domain containing proteins in yeast and human are involved in a large variety of cellular processes such as DNA repair, cell cycle arrest, or pre-mRNA processing. Since the first FHA-domain protein, kinase-associated protein phosphatase (KAPP) was found in plants, the interest in plant FHA-containing proteins has increased dramatically, mainly due to the important role of FHA domain-containing proteins in plant growth and development. In this review, we provide a comprehensive overview of the fundamental properties of FHA domain-containing proteins in plants, and systematically summarized and analyzed the research progress of proteins containing the FHA domain in plants. We also emphasized that AT5G47790 and its homologs may play an important role as the regulatory subunit of protein phosphatase 1 (PP1) in plants.
Collapse
Affiliation(s)
- Qiuling Wang
- Institute of Future Agriculture, State Key Laboratory of Crop Stress Biology for Arid Areas, State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China.
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
| |
Collapse
|
6
|
Nuclear Inhibitor of Protein Phosphatase 1 (NIPP1) Regulates CNS Tau Phosphorylation and Myelination During Development. Mol Neurobiol 2022; 59:7486-7494. [PMID: 36198882 PMCID: PMC9724999 DOI: 10.1007/s12035-022-03040-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 09/16/2022] [Indexed: 10/10/2022]
Abstract
Nuclear inhibitor of protein phosphatase 1 (NIPP1) is a known regulator of gene expression and plays roles in many physiological or pathological processes such as stem cell proliferation and skin inflammation. While NIPP1 has many regulatory roles in proliferating cells, its function in the central nervous system (CNS) has not been directly investigated. In the present study, we examined NIPP1 CNS function using a conditional knockout (cKO) mouse model in which the Nipp1 gene is excised from neural precursor cells. These mice exhibited severe developmental impairments that led to premature lethality. To delineate the neurological changes occurring in these animals, we first assessed microtubule-associated protein tau, a known target of NIPP1 activity. We found that phosphorylation of tau is significantly enhanced in NIPP1 cKO mice. Consistent with this, we found altered AKT and PP1 activity in NIPP1 cKO mice, suggesting that increased tau phosphorylation likely results from a shift in kinase/phosphatase activity. Secondly, we observed tremors in the NIPP1 cKO mice which prompted us to explore the integrity of the myelin sheath, an integral structure for CNS function. We demonstrated that in NIPP1 cKO mice, there is a significant decrease in MBP protein expression in the cortex, along with deficits in both the conduction of compound action potentials (CAP) and the percentage of myelinated axons in the optic nerve. Our study suggests that NIPP1 in neural precursor cells regulates phosphorylation of tau and CNS myelination and may represent a novel therapeutic target for neurodegenerative diseases.
Collapse
|
7
|
Hanaki S, Habara M, Masaki T, Maeda K, Sato Y, Nakanishi M, Shimada M. PP1 regulatory subunit NIPP1 regulates transcription of E2F1 target genes following DNA damage. Cancer Sci 2021; 112:2739-2752. [PMID: 33939241 PMCID: PMC8253265 DOI: 10.1111/cas.14924] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/14/2021] [Accepted: 04/14/2021] [Indexed: 12/21/2022] Open
Abstract
DNA damage induces transcriptional repression of E2F1 target genes and a reduction in histone H3‐Thr11 phosphorylation (H3‐pThr11) at E2F1 target gene promoters. Dephosphorylation of H3‐pThr11 is partly mediated by Chk1 kinase and protein phosphatase 1γ (PP1γ) phosphatase. Here, we isolated NIPP1 as a regulator of PP1γ‐mediated H3‐pThr11 by surveying nearly 200 PP1 interactor proteins. We found that NIPP1 inhibits PP1γ‐mediated dephosphorylation of H3‐pThr11 both in vivo and in vitro. By generating NIPP1‐depleted cells, we showed that NIPP1 is required for cell proliferation and the expression of E2F1 target genes. Upon DNA damage, activated protein kinase A (PKA) phosphorylated the NIPP1‐Ser199 residue, adjacent to the PP1 binding motif (RVxF), and triggered the dissociation of NIPP1 from PP1γ, leading to the activation of PP1γ. Furthermore, the inhibition of PKA activity led to the activation of E2F target genes. Statistical analysis confirmed that the expression of NIPP1 was positively correlated with E2F target genes. Taken together, these findings demonstrate that the PP1 regulatory subunit NIPP1 modulates E2F1 target genes by linking PKA and PP1γ during DNA damage.
Collapse
Affiliation(s)
- Shunsuke Hanaki
- Department of Biochemistry, Joint Faculty of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Makoto Habara
- Department of Biochemistry, Joint Faculty of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Takahiro Masaki
- Department of Biochemistry, Joint Faculty of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Keisuke Maeda
- Department of Biochemistry, Joint Faculty of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Yuki Sato
- Department of Biochemistry, Joint Faculty of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Makoto Nakanishi
- Division of Cancer Biology, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Midori Shimada
- Department of Biochemistry, Joint Faculty of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| |
Collapse
|
8
|
Upregulation of Phosphatase 1 Nuclear-Targeting Subunit (PNUTS) Is an Independent Predictor of Poor Prognosis in Prostate Cancer. DISEASE MARKERS 2020; 2020:7050146. [PMID: 32377272 PMCID: PMC7196962 DOI: 10.1155/2020/7050146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 01/17/2020] [Indexed: 01/07/2023]
Abstract
Protein phosphatase 1 nuclear-targeting subunit (PNUTS) is ubiquitously expressed and associates with PTEN and protein phosphatase 1 (PP1) to control its activity. The role of PNUTS overexpression has hardly been studied in cancer. In this study, we used immunohistochemistry to quantitate PNUTS expression on a tissue microarray containing 17,747 clinical prostate cancer specimens. As compared to normal prostate epithelium, PNUTS expression was often higher in cancer. Among 12,235 interpretable tumors, PNUTS staining was negative in 21%, weak in 34%, moderate in 35%, and strong in 10% of cases. High PNUTS expression was associated with higher tumor stage, classical and quantitative Gleason grade, nodal stage, surgical margin, Ki67 labeling index, and early biochemical recurrence (p < 0.0001 each). PNUTS expression proved to be a moderate prognostic parameter with a maximal univariable Cox proportional hazard for PSA recurrence-free survival of 2.21 compared with 5.91 for Gleason grading. It was independent from established prognostic parameters in multivariable analysis. Comparison with molecular data available from earlier studies using the same TMA identified associations between high PNUTS expression and elevated androgen receptor expression (p < 0.0001), presence of TMPRSS2:ERG fusion (p < 0.0001), and 8 of 11 chromosomal deletions (3p13, 5q21, 8p21, 10q23, 12p13, 13q14, 16q24, and 17p13; p < 0.05 each). Particularly strong associations with PTEN and 12p13 deletions (p < 0.0001 each) may indicate a functional relationship, which has already been established for PNUTS and PTEN. PNUTS had no additional role on outcome in PTEN-deleted cancers. In conclusion, the results of our study identify high PNUTS protein levels as a predictor of poor prognosis possibly linked to increased levels of genomic instability. PNUTS measurement, either alone or in combination, might be of clinical utility in prostate cancers.
Collapse
|
9
|
Phosphatase Regulator NIPP1 Restrains Chemokine-Driven Skin Inflammation. J Invest Dermatol 2020; 140:1576-1588. [PMID: 31972250 DOI: 10.1016/j.jid.2020.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 12/20/2019] [Accepted: 01/05/2020] [Indexed: 02/06/2023]
Abstract
Nuclear inhibitor of protein phosphatase 1 (NIPP1) is a ubiquitously expressed nuclear protein that regulates functions of protein serine/threonine phosphatase-1 in cell proliferation and lineage specification. The role of NIPP1 in tissue homeostasis is not fully understood. This study shows that the selective deletion of NIPP1 in mouse epidermis resulted in epidermal hyperproliferation, a reduced adherence of basal keratinocytes, and a gradual decrease in the stemness of hair follicle stem cells, culminating in hair loss. This complex phenotype was associated with chronic sterile skin inflammation and could be partially rescued by dexamethasone treatment. NIPP1-deficient keratinocytes massively expressed proinflammatory chemokines and immunomodulatory proteins in a cell-autonomous manner. Chemokines subsequently induced the recruitment and activation of immune cells, in particular conventional dendritic cells and Langerhans cells, accounting for the chronic inflammation phenotype. The data identifies NIPP1 as a key regulator of epidermal homeostasis and as a potential target for the treatment of inflammatory skin diseases.
Collapse
|
10
|
Cell Cycle and DNA Repair Regulation in the Damage Response: Protein Phosphatases Take Over the Reins. Int J Mol Sci 2020; 21:ijms21020446. [PMID: 31936707 PMCID: PMC7014277 DOI: 10.3390/ijms21020446] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/29/2019] [Accepted: 01/02/2020] [Indexed: 12/14/2022] Open
Abstract
Cells are constantly suffering genotoxic stresses that affect the integrity of our genetic material. Genotoxic insults must be repaired to avoid the loss or inappropriate transmission of the genetic information, a situation that could lead to the appearance of developmental abnormalities and tumorigenesis. To combat this threat, eukaryotic cells have evolved a set of sophisticated molecular mechanisms that are collectively known as the DNA damage response (DDR). This surveillance system controls several aspects of the cellular response, including the detection of lesions, a temporary cell cycle arrest, and the repair of the broken DNA. While the regulation of the DDR by numerous kinases has been well documented over the last decade, the complex roles of protein dephosphorylation have only recently begun to be investigated. Here, we review recent progress in the characterization of DDR-related protein phosphatases during the response to a DNA lesion, focusing mainly on their ability to modulate the DNA damage checkpoint and the repair of the damaged DNA. We also discuss their protein composition and structure, target specificity, and biochemical regulation along the different stages encompassed in the DDR. The compilation of this information will allow us to better comprehend the physiological significance of protein dephosphorylation in the maintenance of genome integrity and cell viability in response to genotoxic stress.
Collapse
|
11
|
Dwivedi SKD, Shameer K, Dey A, Mustafi SB, Xiong X, Bhattacharya U, Neizer-Ashun F, Rao G, Wang Y, Ivan C, Yang D, Dudley JT, Xu C, Wren JD, Mukherjee P, Bhattacharya R. KRCC1: A potential therapeutic target in ovarian cancer. FASEB J 2019; 34:2287-2300. [PMID: 31908025 DOI: 10.1096/fj.201902259r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/14/2019] [Accepted: 11/25/2019] [Indexed: 01/11/2023]
Abstract
Using a systems biology approach to prioritize potential points of intervention in ovarian cancer, we identified the lysine rich coiled-coil 1 (KRCC1), as a potential target. High-grade serous ovarian cancer patient tumors and cells express significantly higher levels of KRCC1 which correlates with poor overall survival and chemoresistance. We demonstrate that KRCC1 is predominantly present in the chromatin-bound nuclear fraction, interacts with HDAC1, HDAC2, and with the serine-threonine phosphatase PP1CC. Silencing KRCC1 inhibits cellular plasticity, invasive properties, and potentiates apoptosis resulting in reduced tumor growth. These phenotypes are associated with increased acetylation of histones and with increased phosphorylation of H2AX and CHK1, suggesting the modulation of transcription and DNA damage that may be mediated by the action of HDAC and PP1CC, respectively. Hence, we address an urgent need to develop new targets in cancer.
Collapse
Affiliation(s)
| | - Khader Shameer
- Institute of Next Generation Healthcare (INGH), Icahn Institute for Data Science and Genomic Technology, Department of Genetics and Genomic Sciences, Mount Sinai Health System, New York, NY, USA
| | - Anindya Dey
- Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | | | - Xunhao Xiong
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Udayan Bhattacharya
- Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Fiifi Neizer-Ashun
- Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Geeta Rao
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Yue Wang
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Cristina Ivan
- Department of Experimental Therapeutics & Center for RNA Interference and Non-coding RNA, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA
| | - Da Yang
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Joel T Dudley
- Institute of Next Generation Healthcare (INGH), Icahn Institute for Data Science and Genomic Technology, Department of Genetics and Genomic Sciences, Mount Sinai Health System, New York, NY, USA
| | - Chao Xu
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jonathan D Wren
- Departments of Biochemistry & Molecular Biology and Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Priyabrata Mukherjee
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Resham Bhattacharya
- Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| |
Collapse
|
12
|
Ramos F, Villoria MT, Alonso-Rodríguez E, Clemente-Blanco A. Role of protein phosphatases PP1, PP2A, PP4 and Cdc14 in the DNA damage response. Cell Stress 2019; 3:70-85. [PMID: 31225502 PMCID: PMC6551743 DOI: 10.15698/cst2019.03.178] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Maintenance of genome integrity is fundamental for cellular physiology. Our hereditary information encoded in the DNA is intrinsically susceptible to suffer variations, mostly due to the constant presence of endogenous and environmental genotoxic stresses. Genomic insults must be repaired to avoid loss or inappropriate transmission of the genetic information, a situation that could lead to the appearance of developmental anomalies and tumorigenesis. To safeguard our genome, cells have evolved a series of mechanisms collectively known as the DNA damage response (DDR). This surveillance system regulates multiple features of the cellular response, including the detection of the lesion, a transient cell cycle arrest and the restoration of the broken DNA molecule. While the role of multiple kinases in the DDR has been well documented over the last years, the intricate roles of protein dephosphorylation have only recently begun to be addressed. In this review, we have compiled recent information about the function of protein phosphatases PP1, PP2A, PP4 and Cdc14 in the DDR, focusing mainly on their capacity to regulate the DNA damage checkpoint and the repair mechanism encompassed in the restoration of a DNA lesion.
Collapse
Affiliation(s)
- Facundo Ramos
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - María Teresa Villoria
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - Esmeralda Alonso-Rodríguez
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - Andrés Clemente-Blanco
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| |
Collapse
|
13
|
Structure-Guided Exploration of SDS22 Interactions with Protein Phosphatase PP1 and the Splicing Factor BCLAF1. Structure 2019; 27:507-518.e5. [PMID: 30661852 DOI: 10.1016/j.str.2018.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 10/09/2018] [Accepted: 12/03/2018] [Indexed: 01/29/2023]
Abstract
SDS22 is an ancient regulator of protein phosphatase-1 (PP1). Our crystal structure of SDS22 shows that its twelve leucine-rich repeats adopt a banana-shaped fold that is shielded from solvent by capping domains at its extremities. Subsequent modeling and biochemical studies revealed that the concave side of SDS22 likely interacts with PP1 helices α5 and α6, which are distal from the binding sites of many previously described PP1 interactors. Accordingly, we found that SDS22 acts as a "third" subunit of multiple PP1 holoenzymes. The crystal structure of SDS22 also revealed a large basic surface patch that enables binding of a phosphorylated form of splicing factor BCLAF1. Taken together, our data provide insights into the formation of PP1:SDS22 and the recruitment of additional interaction proteins, such as BCLAF1.
Collapse
|
14
|
Ferreira M, Verbinnen I, Fardilha M, Van Eynde A, Bollen M. The deletion of the protein phosphatase 1 regulator NIPP1 in testis causes hyperphosphorylation and degradation of the histone methyltransferase EZH2. J Biol Chem 2018; 293:18031-18039. [PMID: 30305391 DOI: 10.1074/jbc.ac118.005577] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/25/2018] [Indexed: 12/15/2022] Open
Abstract
Germ cell proliferation is epigenetically controlled, mainly through DNA methylation and histone modifications. However, the pivotal epigenetic regulators of germ cell self-renewal and differentiation in postnatal testis are still poorly defined. The histone methyltransferase enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of Polycomb repressive complex 2, represses target genes through trimethylation of histone H3 at Lys-27 (H3K27me3), and interacts (in)directly with both protein phosphatase 1 (PP1) and nuclear inhibitor of PP1 (NIPP1). Here, we report that postnatal, testis-specific ablation of NIPP1 in mice results in loss of EZH2 and reduces H3K27me3 levels. Mechanistically, the NIPP1 deletion abrogated PP1-mediated EZH2 dephosphorylation at two cyclin-dependent kinase sites (Thr-345/487), thereby generating hyperphosphorylated EZH2, which is a substrate for proteolytic degradation. Accordingly, alanine mutation of these residues prolonged the half-life of EZH2 in male germ cells. Our study discloses a key role for the PP1:NIPP1 holoenzyme in stabilizing EZH2 and maintaining the H3K27me3 mark on genes that are important for germ cell development and spermatogenesis.
Collapse
Affiliation(s)
- Mónica Ferreira
- From the Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium and; Institute for Research in Biomedicine (iBiMED), Health Sciences Department, University of Aveiro, 3810 Aveiro, Portugal
| | - Iris Verbinnen
- From the Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium and
| | - Margarida Fardilha
- Institute for Research in Biomedicine (iBiMED), Health Sciences Department, University of Aveiro, 3810 Aveiro, Portugal
| | - Aleyde Van Eynde
- From the Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium and.
| | - Mathieu Bollen
- From the Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium and.
| |
Collapse
|
15
|
Wu D, De Wever V, Derua R, Winkler C, Beullens M, Van Eynde A, Bollen M. A substrate-trapping strategy for protein phosphatase PP1 holoenzymes using hypoactive subunit fusions. J Biol Chem 2018; 293:15152-15162. [PMID: 30115685 DOI: 10.1074/jbc.ra118.004132] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/13/2018] [Indexed: 01/24/2023] Open
Abstract
The protein Ser/Thr phosphatase PP1 catalyzes an important fraction of protein dephosphorylation events and forms highly specific holoenzymes through an association with regulatory interactors of protein phosphatase one (RIPPOs). The functional characterization of individual PP1 holoenzymes is hampered by the lack of straightforward strategies for substrate mapping. Because efficient substrate recruitment often involves binding to both PP1 and its associated RIPPO, here we examined whether PP1-RIPPO fusions can be used to trap substrates for further analysis. Fusions of an hypoactive point mutant of PP1 and either of four tested RIPPOs accumulated in HEK293T cells with their associated substrates and were co-immunoprecipitated for subsequent identification of the substrates by immunoblotting or MS analysis. Hypoactive fusions were also used to study RIPPOs themselves as substrates for associated PP1. In contrast, substrate trapping was barely detected with active PP1-RIPPO fusions or with nonfused PP1 or RIPPO subunits. Our results suggest that hypoactive fusions of PP1 subunits represent an easy-to-use tool for substrate identification of individual holoenzymes.
Collapse
Affiliation(s)
- Dan Wu
- From the Laboratory of Biosignaling and Therapeutics
| | | | - Rita Derua
- the Protein Phosphorylation and Proteomics Lab, KU Leuven Department of Cellular and Molecular Medicine, and.,SyBioMa, University of Leuven, 3000 Leuven, Belgium
| | | | | | | | | |
Collapse
|