DOCSLIB.ORG

Autophosphorylation and Pin1 Binding Coordinate DNA Damage-Induced

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Autophosphorylation and Pin1 binding coordinate DNA PNAS PLUS damage-induced HIPK2 activation and cell death Nadja Bitomskya, Elisa Conrada, Christian Moritzb, Tilman Polonio-Vallona, Dirk Sombroeka, Kathrin Schultheissa, Carolina Glasa, Vera Greinera, Christoph Herbela, Fiamma Mantovanic,d, Giannino del Salc,d, Francesca Perib, and Thomas G. Hofmanna,1 aGerman Cancer Research Center, Cellular Senescence Group, Deutsches Krebsforschungszentrum-Zentrum für Molekulare Biologie der Universität Heidelberg Alliance (DKFZ-ZMBH), 69120 Heidelberg, Germany; bEuropean Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany; cLaboratorio Nazionale del Consorzio Interuniversitario per le Biotecnologie (LNCIB), 34012 Trieste, Italy; and dDipartimento di Scienze della Vita, Università degli Studi di Trieste, 34128 Trieste, Italy Edited by Carol Prives, Columbia University, New York, NY, and approved September 23, 2013 (received for review May 28, 2013) Excessive genome damage activates the apoptosis response. Protein therapeutic drug treatment through different signaling pathways kinase HIPK2 is a key regulator of DNA damage-induced apoptosis. including phosphorylation of p53 at serine 46 and phosphoryla- Here, we deciphered the molecular mechanism of HIPK2 activa- tion-mediated degradation of antiapoptotic molecules such as tion and show its relevance for DNA damage-induced apoptosis corepressor CtBP and transcription factor ΔNp63α (14–20). in cellulo fi and in vivo. HIPK2 autointeracts and site-speci cally Unstressed cells and cells recovering from DNA damage keep autophosphorylates upon DNA damage at Thr880/Ser882. Auto- HIPK2 activity low through targeting the kinase for protea- phosphorylation regulates HIPK2 activity and mutation of the phosphorylation-acceptor sites deregulates p53 Ser46 phosphory- some-dependent degradation by the ubiquitin ligases WSB1 lation and apoptosis in cellulo. Moreover, HIPK2 autophosphory- and Siah-1 (21-23). In response to DNA damage, HIPK2 is lation is conserved between human and zebrafish and is important stabilized through a mechanism involving the DNA damage for DNA damage-induced apoptosis in vivo. Mechanistically, auto- checkpoint kinases ATM and ATR, which facilitate dissociation phosphorylation creates a binding signal for the phospho-specific of the HIPK2–Siah-1 complex, at least in part, by phosphor- isomerase Pin1. Pin1 links HIPK2 activation to its stabilization by ylation of Siah-1 (16, 22). However, the detailed mechanisms CELL BIOLOGY inhibiting HIPK2 polyubiquitination and modulating Siah-1–HIPK2 underlying HIPK2 activation upon genotoxic stress remains interaction. Concordantly, Pin1 is required for DNA damage-induced still unclear. HIPK2 stabilization and p53 Ser46 phosphorylation and is essential In the present study, we investigated the molecular mecha- in cellulo fi for induction of apotosis both and in zebra sh. Our results nism regulating HIPK2 activation in response to DNA damage. identify an evolutionary conserved mechanism regulating DNA We show that HIPK2 activation is facilitated through a mecha- damage-induced apoptosis. nism involving HIPK2 oligomerization and site-specific auto- phosphorylation at Thr880/Ser882. HIPK2 autophosphorylation ctivation of the apoptotic response upon severe genome increases its kinase activity and apoptotic function both in cellulo damage plays a crucial role in suppression of cellular trans- A and in vivo. Mechanistically, we show that phosphorylation at formation and cancer development. In addition, apoptosis is a major mechanism of action underlying the efficacy of widely used Thr880/Ser882 serves as a binding signal for the prolyl-peptidyl DNA-damaging cancer therapies including radiotherapy and cis/trans isomerase Pin1, which links HIPK2 activation to its chemotherapy. To gain insight into the mechanisms underlying stabilization. cancer cell resistance to therapy, detailed knowledge about the molecular players and the regulatory network governing the Significance DNA damage-induced apoptosis response is of fundamental importance. Activation of the cell death (apoptosis) program is a major Tumor suppressor p53 is a master regulator of the DNA principle of DNA-damaging cancer treatments including ion- damage response and drives expression of different sets of target izing radiation and chemotherapeutic drug treatment. The genes that regulate cell fate decisions as DNA repair, senes- protein kinase HIPK2 plays a key role in radiosensitivity and cence, and cell death (1, 2). p53 target gene selection after DNA chemosensitivity. Here, we found that HIPK2 autointeracts damage is controlled in part at the level of its posttranslational and autophosphorylates after DNA damage. HIPK2 auto- modifications, including site-specific phosphorylation and acety- phosphorylation is conserved in evolution and regulates its lation. p53 phosphorylation is mediated by the DNA damage apoptosis-inducing activity by facilitating binding of the checkpoint kinases ATM and ATR as well as their downstream isomerase Pin1. Pin1 couples HIPK2 activation to its stabili- kinases Chk1, Chk2, and HIPK2, which control p53 stability, zation and is essential for DNA damage-induced apoptosis in activity, and target gene selection through a complex signaling cancer cells and in zebrafish. Our findings identify a mecha- network (3, 4). nism linking HIPK2 activation to its stabilization and high- The Ser/Thr protein kinase homeodomain interacting protein light a conserved function of HIPK2 and Pin1 in the DNA kinase 2 (HIPK2) is an evolutionarily conserved regulator of cell damage-induced apoptosis response. death and cell growth during development and in response to Author contributions: N.B. and T.G.H. designed research; N.B., E.C., C.M., T.P.-V., D.S., K.S., cellular stress (5, 6). There is growing evidence that HIPK2 acts C.G., V.G., C.H., and F.M. performed research; G.d.S. and F.P. contributed new reagents/ as a tumor suppressor both in mice and men (7–10) and that the analytic tools; N.B., E.C., C.M., T.P.-V., D.S., K.S., C.G., V.G., C.H., F.M., G.d.S., and T.G.H. kinase is functionally deregulated by cellular and candidate viral analyzed data; and T.G.H. wrote the paper. oncogenes (11). In addition to its role in cancer, HIPK2 dys- The authors declare no conflict of interest. regulation has been linked to pathophysiology including neu- This article is a PNAS Direct Submission. rodegeneration and kidney fibrosis (7, 12, 13). 1To whom correspondence should be addressed. E-mail: [email protected]. HIPK2 channels the apoptotic response upon DNA damage This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10. induced by UV irradiation, ionizing radiation (IR), and chemo- 1073/pnas.1310001110/-/DCSupplemental. www.pnas.org/cgi/doi/10.1073/pnas.1310001110 PNAS Early Edition | 1of10 Downloaded by guest on September 29, 2021 Results phosphorylates at Thr880/Ser882 in vitro and that our antibodies HIPK2 Autophosphorylates at Thr880/Ser882 in Vitro. To determine specifically recognize Thr880/Ser882-phosphorylated HIPK2. whether HIPK2 autophosphorylates, we expressed kinase- To gain insight into the mechanism underlying HIPK2 auto- proficient His-HIPK2 and kinase-deficient His-HIPK2K221A in phosphorylation, we examined whether HIPK2 may autophos- Escherichia coli and purified the proteins by metal-affinity phorylate in trans through an intermolecular mechanism. Thus, chromatography. In vitro kinase assays using [γ-32P]-ATP as a we performed in vitro kinase assays by using bacterially ex- K221A phosphate donor showed that only wild-type HIPK2 protein pressed His-HIPK2 as substrate for Flag-HIPK2 and Flag- K221A autophosphorylated and phosphorylated the substrate myelin HIPK2 . To subsequently separate the autophosphorylated basic protein (MBP) (Fig. 1A). Immunoblot analysis with a Flag-HIPK2 from its substrate His-HIPK2K221A, we purified the pan-phospho-specific Ser/Thr (pSer/pThr) antibody showed His-HIPK2K221A protein from the kinase reaction under dena- strong reactivity with the wild-type form of HIPK2, but not turing conditions by using metal-affinity purification on the His with kinase-deficient HIPK2K221A (Fig. 1B). In addition, pre- tag of the substrate protein. Immunoblot analysis of the His- treatment of HIPK2 with λ-phosphatase abrogated reactivity of HIPK2K221A showed clear phosphorylation at Thr880/Ser882 in the pSer/pThr antibody (Fig. 1C). the presence of wild-type HIPK2, whereas virtually no phos- For mapping of the autophosphorylation sites, we focused on the phorylation was found using HIPK2K221A (Fig. 1E). These results C-terminal regulatory part of HIPK2, which contains an utoinhi- suggest that HIPK2 autophosphorylates in trans through an bitory domain (24). We speculated that phosphorylation in this part intermolecular mechanism. may modulate HIPK2 activity by attenuating the autoinhibitory function of the C terminus. In vitro mapping experiments of the HIPK2 Autophosphorylates at Thr880/Ser882 upon DNA Damage. We HIPK2 autophosphorylation sites using site-directed mutagenesis next investigated whether HIPK2 autophosphorylates in cells. identified Thr880/Ser882 as the main HIPK2 autophosphorylation The pThr880/pSer882 HIPK2 antibody specifically recognized site (Fig. 1D). Additional minor sites of autophosphorylation were ectopically expressed Thr880/Ser882-phosphorylated HIPK2 in detectable that were largely abolished through mutation of addi- cells (Fig. S1A). To investigate whether HIPK2 autophosphor- tional six Ser/Thr residues (S668,
Recommended publications
  • SPEN Induces Mir-4652-3P to Target HIPK2 in Nasopharyngeal Carcinoma

    SPEN Induces Mir-4652-3P to Target HIPK2 in Nasopharyngeal Carcinoma

    Li et al. Cell Death and Disease (2020) 11:509 https://doi.org/10.1038/s41419-020-2699-2 Cell Death & Disease ARTICLE Open Access SPEN induces miR-4652-3p to target HIPK2 in nasopharyngeal carcinoma Yang Li1,YuminLv1, Chao Cheng2,YanHuang3,LiuYang1, Jingjing He1,XingyuTao1, Yingying Hu1,YutingMa1, Yun Su1,LiyangWu1,GuifangYu4, Qingping Jiang5,ShuLiu6,XiongLiu7 and Zhen Liu1 Abstract SPEN family transcriptional repressor (SPEN), also known as the SMART/HDAC1-associated repressor protein (SHARP), has been reported to modulate the malignant phenotypes of breast cancer, colon cancer, and ovarian cancer. However, its role and the detail molecular basis in nasopharyngeal carcinoma (NPC) remain elusive. In this study, the SPEN mRNA and protein expression was found to be increased in NPC cells and tissues compared with nonmalignant nasopharyngeal epithelial cells and tissues. Elevated SPEN protein expression was found to promote the pathogenesis of NPC and lead to poor prognosis. Knockdown of SPEN expression resulted in inactivation ofPI3K/AKT and c-JUN signaling, thereby suppressing NPC migration and invasion. In addition, miR-4652-3p was found to be a downstream inducer of SPEN by targeting the homeodomain interacting protein kinase 2 (HIPK2) gene, a potential tumor suppressor that reduces the activation of epithelial–mesenchymal transition (EMT) signaling, thereby reducing its expression and leading to increased NPC migration, invasion, and metastasis. In addition, SPEN was found to induce miR-4652-3p expression by activating PI3K/AKT/c-JUN signaling to target HIPK2. Our data provided a new molecular mechanism for SPEN as a metastasis promoter through activation of PI3K/AKT signaling, thereby stimulating the c-JUN/miR-4652-3p axis to target HIPK2 in NPC.
  • HIPK2–P53ser46 Damage Response Pathway Is Involved in Temozolomide-Induced Glioblastoma Cell Death Yang He, Wynand P

    HIPK2–P53ser46 Damage Response Pathway Is Involved in Temozolomide-Induced Glioblastoma Cell Death Yang He, Wynand P

    Published OnlineFirst February 22, 2019; DOI: 10.1158/1541-7786.MCR-18-1306 Cell Fate Decisions Molecular Cancer Research The SIAH1–HIPK2–p53ser46 Damage Response Pathway is Involved in Temozolomide-Induced Glioblastoma Cell Death Yang He, Wynand P. Roos, Qianchao Wu, Thomas G. Hofmann, and Bernd Kaina Abstract Patients suffering from glioblastoma have a dismal prog- in chromatin-immunoprecipitation experiments, in which nosis, indicating the need for new therapeutic targets. Here p-p53ser46 binding to the Fas promotor was regulated by we provide evidence that the DNA damage kinase HIPK2 HIPK2. Other pro-apoptotic proteins such as PUMA, and its negative regulatory E3-ubiquitin ligase SIAH1 are NOXA, BAX, and PTEN were not affected in HIPK2kd, and critical factors controlling temozolomide-induced cell also double-strand breaks following temozolomide remain- death. We show that HIPK2 downregulation (HIPK2kd) ed unaffected. We further show that downregulation of significantly reduces the level of apoptosis. This was not the HIPK2 inactivator SIAH1 significantly ameliorates the case in glioblastoma cells expressing the repair protein temozolomide-induced apoptosis, suggesting that the MGMT, suggesting that the primary DNA lesion responsible ATM/ATR target SIAH1 together with HIPK2 plays a pro- 6 for triggering HIPK2-mediated apoptosis is O -methylguanine. apoptotic role in glioma cells exhibiting p53wt status. A Upon temozolomide treatment, p53 becomes phosphory- database analysis revealed that SIAH1, but not SIAH2, is lated whereby HIPK2kd had impact exclusively on ser46, significantly overexpressed in glioblastomas. but not ser15. Searching for the transcriptional target of p-p53ser46, we identified the death receptor FAS (CD95, Implications: The identification of a novel apoptotic APO-1) being involved.
  • Updates on HIPK2: a Resourceful Oncosuppressor for Clearing Cancer Gabriella D’Orazi1,2*, Cinzia Rinaldo2,3 and Silvia Soddu2*

    Updates on HIPK2: a Resourceful Oncosuppressor for Clearing Cancer Gabriella D’Orazi1,2*, Cinzia Rinaldo2,3 and Silvia Soddu2*

    D’Orazi et al. Journal of Experimental & Clinical Cancer Research 2012, 31:63 http://www.jeccr.com/content/31/1/63 REVIEW Open Access Updates on HIPK2: a resourceful oncosuppressor for clearing cancer Gabriella D’Orazi1,2*, Cinzia Rinaldo2,3 and Silvia Soddu2* Abstract Homeodomain-interacting protein kinase 2 (HIPK2) is a multitalented protein that exploits its kinase activity to modulate key molecular pathways in cancer to restrain tumor growth and induce response to therapies. HIPK2 phosphorylates oncosuppressor p53 for apoptotic activation. In addition, also p53-independent apoptotic pathways are regulated by HIPK2 and can be exploited for anticancer purpose too. Therefore, HIPK2 activity is considered a central switch in targeting tumor cells toward apoptosis upon genotoxic damage and the preservation and/or restoration of HIPK2 function is crucial for an efficient tumor response to therapies. As a proof of principle, HIPK2 knockdown impairs p53 function, induces chemoresistance, angiogenesis, and tumor growth in vivo,onthe contrary, HIPK2 overexpression activates apoptotic pathways, counteracts hypoxia, inhibits angiogenesis, and induces chemosensitivity both in p53-dependent and -independent ways. The role of HIPK2 in restraining tumor development was also confirmed by studies with HIPK2 knockout mice. Recent findings demonstrated that HIPK2 inhibitions do exist in tumors and depend by several mechanisms including HIPK2 cytoplasmic localization, protein degradation, and loss of heterozygosity (LOH), recapitulating the biological outcome obtained by RNA interference studies in tumor cells, such as p53 inactivation, resistance to therapies, apoptosis inhibition, and tumor progression. These findings may lead to new diagnostic and therapeutic approaches for treating cancer patients. This review will focus on the last updates about HIPK2 contribution in tumorigenesis and cancer treatment.
  • Mithramycin Represses Basal and Cigarette Smoke–Induced Expression of ABCG2 and Inhibits Stem Cell Signaling in Lung and Esophageal Cancer Cells

    Mithramycin Represses Basal and Cigarette Smoke–Induced Expression of ABCG2 and Inhibits Stem Cell Signaling in Lung and Esophageal Cancer Cells

    Cancer Therapeutics, Targets, and Chemical Biology Research Mithramycin Represses Basal and Cigarette Smoke–Induced Expression of ABCG2 and Inhibits Stem Cell Signaling in Lung and Esophageal Cancer Cells Mary Zhang1, Aarti Mathur1, Yuwei Zhang1, Sichuan Xi1, Scott Atay1, Julie A. Hong1, Nicole Datrice1, Trevor Upham1, Clinton D. Kemp1, R. Taylor Ripley1, Gordon Wiegand2, Itzak Avital2, Patricia Fetsch3, Haresh Mani6, Daniel Zlott4, Robert Robey5, Susan E. Bates5, Xinmin Li7, Mahadev Rao1, and David S. Schrump1 Abstract Cigarette smoking at diagnosis or during therapy correlates with poor outcome in patients with lung and esophageal cancers, yet the underlying mechanisms remain unknown. In this study, we observed that exposure of esophageal cancer cells to cigarette smoke condensate (CSC) led to upregulation of the xenobiotic pump ABCG2, which is expressed in cancer stem cells and confers treatment resistance in lung and esophageal carcinomas. Furthermore, CSC increased the side population of lung cancer cells containing cancer stem cells. Upregulation of ABCG2 coincided with increased occupancy of aryl hydrocarbon receptor, Sp1, and Nrf2 within the ABCG2 promoter, and deletion of xenobiotic response elements and/or Sp1 sites markedly attenuated ABCG2 induction. Under conditions potentially achievable in clinical settings, mithramycin diminished basal as well as CSC- mediated increases in AhR, Sp1, and Nrf2 levels within the ABCG2 promoter, markedly downregulated ABCG2, and inhibited proliferation and tumorigenicity of lung and esophageal cancer cells. Microarray analyses revealed that mithramycin targeted multiple stem cell–related pathways in vitro and in vivo. Collectively, our findings provide a potential mechanistic link between smoking status and outcome of patients with lung and esophageal cancers, and support clinical use of mithramycin for repressing ABCG2 and inhibiting stem cell signaling in thoracic malignancies.
  • HER2 Stabilizes EGFR and Itself by Altering Autophosphorylation Patterns in a Manner That Overcomes Regulatory Mechanisms and Pr

    HER2 Stabilizes EGFR and Itself by Altering Autophosphorylation Patterns in a Manner That Overcomes Regulatory Mechanisms and Pr

    Oncogene (2013) 32, 4169–4180 & 2013 Macmillan Publishers Limited All rights reserved 0950-9232/13 www.nature.com/onc ORIGINAL ARTICLE HER2 stabilizes EGFR and itself by altering autophosphorylation patterns in a manner that overcomes regulatory mechanisms and promotes proliferative and transformation signaling Z Hartman1, H Zhao1 and YM Agazie1,2 One of the causes of breast cancer is overexpression of the human epidermal growth factor receptor 2 (HER2). Enhanced receptor autophosphorylation and resistance to activation-induced downregulation have been suggested as mechanisms for HER2-induced sustained signaling and cell transformation. However, the molecular mechanisms underlying these possibilities remain incompletely understood. In the current report, we present evidence that show that HER2 overexpression does not lead to receptor hyper-autophosphorylation, but alters patterns in a manner that favors receptor stability and sustained signaling. Specifically, HER2 overexpression blocks epidermal growth factor receptor (EGFR) tyrosine phosphorylation on Y1045 and Y1068, the known docking sites of c-Cbl and Grb2, respectively, whereas promoting phosphorylation on Y1173, the known docking site of the Gab adaptor proteins and phospholipase C gamma. Under these conditions, HER2 itself is phosphorylated on Y1221/1222, with no known role, and on Y1248 that corresponds to Y1173 of EGFR. Interestingly, suppressed EGFR autophosphorylation on the Grb2 and c-Cbl-binding sites correlated with receptor stability and sustained signaling, suggesting that HER2 accomplishes these tasks by altering autophosphorylation patterns. In conformity with these findings, mutation of the Grb2-binding site on EGFR (Y1068F–EGFR) conferred resistance to ligand-induced degradation, which in turn induced sustained signaling, and increased cell proliferation and transformation.
  • Inside Lab Invest

    Inside Lab Invest

    Laboratory Investigation (2012) 0092, 000-000800-801 © 2012 USCAP, Inc All rights reserved 0023-6837/060023-6837/12 $30.00$32.00 INSIDE LLII doi:10.1038/labinvest.2012.82 New gastric carcinoma forestomach and the glandular epithelium advantage of the Akita−/− mouse model of mouse model of the lesser curvature. These changes type 1 diabetes to examine the effects of were not observed at the junction of the uncontrolled hyperglycemia on oral health. See page 883 forestomach and the greater curvature. The investigators demonstrated Furthermore, no histological changes that, although teeth develop normally were observed in heterozygous Smad3+/− in these mice, they exhibit significant heterozygotes or age-matched wild- oral pathology after birth. Beginning type littermate controls. At 10 months, at 4 weeks after birth, the mice began metaplastic lesions in Smad−/− mice to show increased wearing of enamel progressed to high-grade dysplasia. characterized by a modest reduction of Interestingly, there was also an association enamel and dentin. Hypomineralization between the areas of metaplasia and and enamel attrition were accompanied gastritis cystica profunda, which the by microabscesses that progressed to authors interpreted as invading glands, significant tooth destruction and bone although the relationship to gastric loss around the roots of affected teeth. carcinoma was unclear. In summary, the Mechanistically, Akita−/− mice were found authors have developed a novel Smad to have impaired saliva production, knockout mouse model in which to study probably due to a neurologic defect. the pathogenesis of adenocarcinoma of Cell culture experiments using pulp cells the proximal stomach. showed that high glucose inhibited both proliferation and differentiation.
  • Critical Function of Siah2 in Tumorigenesis

    Critical Function of Siah2 in Tumorigenesis

    AIMS Molecular Science, 4(4): 415-423 DOI: 10.3934/molsci.2017.4.415 Received 31 July 2017, Accepted 21 September 2017, Published 11 October 2017 http://www.aimspress.com/journal/Molecular Review Critical function of Siah2 in tumorigenesis Kazunobu Baba, Tadaaki Miyazaki* Department of Probiotics Immunology, Institute for Genetic Medicine, Hokkaido University, North 15 West 7, Kita-ku, Sapporo City, Hokkaido, Japan * Correspondence: Email: [email protected]; Tel: 81-011-706-8095. Abstract: The seven in absentia homolog (Siah) family proteins are components of E3 RING zinc finger ubiquitin ligase complexes that catalyze the ubiquitination of proteins. Siah proteins target their substrates for proteasomal degradation. Evidence is growing that Siah proteins are implicated in the progression of various cancer cells and play a critical role in angiogenesis and tumorigenesis, particularly through Ras, p53, estrogen, and hypoxia inducible factor (HIF)-mediated signaling pathways in response to DNA damage or hypoxia. Keywords: Siah2; Nrf2; ROS metabolism; Hypoxia 1. Introduction The seven in absentia (Sina) gene was initially identified to be critical for photoreceptor cell development in Drosophila [1]. As its mammalian orthologs, murine and human homologs of the Sina gene have also been identified. In Xenopus and mice, Sina homologs (Siahs) were isolated as three Siah proteins, Siah1a, Siah1b, and Siah2, which are encoded by different genes [2]. In contrast, the human Siah proteins consist of two homologs, Siah1 and Siah2, which are encoded by the SIAH1 and SIAH2 genes, respectively [3]. Siah1 and Siah2 have the high sequence similarity of their N-terminal RING finger domain, central cysteine-rich domain, and C-terminal substrate binding domain (SBD); however, Siah1 and Siah2 apparently have distinct but overlapping functions as proteins of a tumor suppressor gene and a proto-oncogene, respectively (Figure 1) [4].
  • Understanding and Exploiting Post-Translational Modifications for Plant Disease Resistance

    Understanding and Exploiting Post-Translational Modifications for Plant Disease Resistance

    biomolecules Review Understanding and Exploiting Post-Translational Modifications for Plant Disease Resistance Catherine Gough and Ari Sadanandom * Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK; [email protected] * Correspondence: [email protected]; Tel.: +44-1913341263 Abstract: Plants are constantly threatened by pathogens, so have evolved complex defence signalling networks to overcome pathogen attacks. Post-translational modifications (PTMs) are fundamental to plant immunity, allowing rapid and dynamic responses at the appropriate time. PTM regulation is essential; pathogen effectors often disrupt PTMs in an attempt to evade immune responses. Here, we cover the mechanisms of disease resistance to pathogens, and how growth is balanced with defence, with a focus on the essential roles of PTMs. Alteration of defence-related PTMs has the potential to fine-tune molecular interactions to produce disease-resistant crops, without trade-offs in growth and fitness. Keywords: post-translational modifications; plant immunity; phosphorylation; ubiquitination; SUMOylation; defence Citation: Gough, C.; Sadanandom, A. 1. Introduction Understanding and Exploiting Plant growth and survival are constantly threatened by biotic stress, including plant Post-Translational Modifications for pathogens consisting of viruses, bacteria, fungi, and chromista. In the context of agriculture, Plant Disease Resistance. Biomolecules crop yield losses due to pathogens are estimated to be around 20% worldwide in staple 2021, 11, 1122. https://doi.org/ crops [1]. The spread of pests and diseases into new environments is increasing: more 10.3390/biom11081122 extreme weather events associated with climate change create favourable environments for food- and water-borne pathogens [2,3]. Academic Editors: Giovanna Serino The significant estimates of crop losses from pathogens highlight the need to de- and Daisuke Todaka velop crops with disease-resistance traits against current and emerging pathogens.
  • Is Glyceraldehyde-3-Phosphate Dehydrogenase a Central Redox Mediator?

    Is Glyceraldehyde-3-Phosphate Dehydrogenase a Central Redox Mediator?

    1 Is glyceraldehyde-3-phosphate dehydrogenase a central redox mediator? 2 Grace Russell, David Veal, John T. Hancock* 3 Department of Applied Sciences, University of the West of England, Bristol, 4 UK. 5 *Correspondence: 6 Prof. John T. Hancock 7 Faculty of Health and Applied Sciences, 8 University of the West of England, Bristol, BS16 1QY, UK. 9 [email protected] 10 11 SHORT TITLE | Redox and GAPDH 12 13 ABSTRACT 14 D-Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an immensely important 15 enzyme carrying out a vital step in glycolysis and is found in all living organisms. 16 Although there are several isoforms identified in many species, it is now recognized 17 that cytosolic GAPDH has numerous moonlighting roles and is found in a variety of 18 intracellular locations, but also is associated with external membranes and the 19 extracellular environment. The switch of GAPDH function, from what would be 20 considered as its main metabolic role, to its alternate activities, is often under the 21 influence of redox active compounds. Reactive oxygen species (ROS), such as 22 hydrogen peroxide, along with reactive nitrogen species (RNS), such as nitric oxide, 23 are produced by a variety of mechanisms in cells, including from metabolic 24 processes, with their accumulation in cells being dramatically increased under stress 25 conditions. Overall, such reactive compounds contribute to the redox signaling of the 26 cell. Commonly redox signaling leads to post-translational modification of proteins, 27 often on the thiol groups of cysteine residues. In GAPDH the active site cysteine can 28 be modified in a variety of ways, but of pertinence, can be altered by both ROS and 29 RNS, as well as hydrogen sulfide and glutathione.
  • Molecular Basis of Tank-Binding Kinase 1 Activation by Transautophosphorylation

    Molecular Basis of Tank-Binding Kinase 1 Activation by Transautophosphorylation

    Molecular basis of Tank-binding kinase 1 activation by transautophosphorylation Xiaolei Maa,1, Elizabeth Helgasonb,1, Qui T. Phungc, Clifford L. Quanb, Rekha S. Iyera, Michelle W. Leec, Krista K. Bowmana, Melissa A. Starovasnika, and Erin C. Dueberb,2 Departments of aStructural Biology, bEarly Discovery Biochemistry, and cProtein Chemistry, Genentech, South San Francisco, CA 94080 Edited by Tony Hunter, Salk Institute for Biological Studies, La Jolla, CA, and approved April 25, 2012 (received for review December 30, 2011) Tank-binding kinase (TBK)1 plays a central role in innate immunity: it the C-terminal scaffolding/dimerization domain (SDD), a do- serves as an integrator of multiple signals induced by receptor- main arrangement that appears to be shared among the IKK mediated pathogen detection and as a modulator of IFN levels. family of kinases (3). Deletion or mutation of the ULD in TBK1 Efforts to better understand the biology of this key immunological or IKKε severely impairs kinase activation and substrate phos- factor have intensified recently as growing evidence implicates phorylation in cells (22, 23). Furthermore, the integrity of the aberrant TBK1 activity in a variety of autoimmune diseases and ULD in IKKβ is not only required for kinase activity (24) but was fi cancers. Nevertheless, key molecular details of TBK1 regulation and shown also to confer substrate speci city in conjunction with the β substrate selection remain unanswered. Here, structures of phos- adjacent SDD (25). Recent crystal structures of the IKK phorylated and unphosphorylated human TBK1 kinase and ubiq- homodimer demonstrate that the ULD and SDD form a joint, uitin-like domains, combined with biochemical studies, indicate three-way interface with the KD within each protomer of the a molecular mechanism of activation via transautophosphorylation.
  • Siah - a Promising Anti-Cancer Target

    Siah - a Promising Anti-Cancer Target

    Author Manuscript Published OnlineFirst on March 1, 2013; DOI: 10.1158/0008-5472.CAN-12-4348 Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited. Siah - a promising anti-cancer target Christina SF Wong1 and Andreas Möller1 1 Tumour Microenvironment Laboratory, Queensland Institute of Medical Research, 300 Herston Road, Herston, Queensland 4006, Australia. Corresponding Author: Andreas Möller ([email protected]) Running title: Siah and Cancer Keywords: Siah1, Siah2, E3 Ubiquitin ligases, Cancer Potential conflict of interest: The authors declare no conflict of interest. Word count: Abstract: 100 words; Text: 2590 words; Number of Figures: 1; Number of Tables: 1 1 Downloaded from cancerres.aacrjournals.org on September 29, 2021. © 2013 American Association for Cancer Research. Author Manuscript Published OnlineFirst on March 1, 2013; DOI: 10.1158/0008-5472.CAN-12-4348 Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited. Abstract: Siah ubiquitin ligases play important roles in a number of signaling pathways involved in the progression and spread of cancer in cell-based models but their role in tumor progression remains controversial. Siah proteins have been described to be both oncogenic as well as tumor-suppressive in a variety of patient cohort studies and animal cancer models. This review collates the current knowledge of Siah in cancer progression and identifies potential methods of translation of these findings into the clinic. Furthermore, key experiments needed to close the gaps in our understanding of the role Siah proteins play in tumor progression are suggested. 2 Downloaded from cancerres.aacrjournals.org on September 29, 2021.
  • Cysteine-179 of Iκb Kinase Β Plays a Critical Role in Enzyme Activation by Promoting Phosphorylation of Activation Loop Serines

    Cysteine-179 of Iκb Kinase Β Plays a Critical Role in Enzyme Activation by Promoting Phosphorylation of Activation Loop Serines

    EXPERIMENTAL and MOLECULAR MEDICINE, Vol. 38, No. 5, 546-552, October 2006 Cysteine-179 of IκB kinase β plays a critical role in enzyme activation by promoting phosphorylation of activation loop serines Mi-Sun Byun, Jin Choi and interaction with ATP. Dae-Myung Jue1 Keywords: cysteine; IκB kinase; NF-κB; phosphor- Department of Biochemistry, College of Medicine ylation; protein serine-threonine kinases The Catholic University of Korea Seoul 137-701, Korea 1Corresponding author: Tel, 82-2-590-1177; Introduction Fax, 82-2-596-4435; E-mail, [email protected] Nuclear factor-κB (NF-κB) is a transcription factor that regulates expression of a wide range of cellular Accepted 20 September 2006 and viral genes that play pivotal roles in immune and 12-14 inflammatory responses (Barnes and Karin, 1997). Abbreviations: 15dPGJ2, 15-deoxy-∆ -PGJ2; GST, glutathione In unstimulated cells, NF-κB is associated with S-transferase; HA, hemagglutinin; IKK, IκB kinase; MAPKKK, mito- inhibitory IκB proteins that inhibit nuclear localization gen-activated protein kinase kinase kinase; MEKK, MAPK/ and DNA binding of NF-κB. In response to stimuli extracellular signal-regulated kinase kinase; NIK, NF-κB-inducing including TNF, IL-1, LPS, or viruses, the IκBs are kinase phosphorylated and subsequently degraded, releasing NF-κB to bind DNA and induce expression of specific Abstract target genes. Phosphorylation of IκB is one of the primary IκB kinase β (IKKβ) subunit of IKK complex is points of regulation in NF-κB activation pathway, and essential for the activation of NF-κB in response to occurs by IκB kinase (IKK). IKK is present as a various proinflammatory signals.