1
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Kodiha M, Azad N, Chu S, Crampton N, Stochaj U. Oxidative stress and signaling through EGFR and PKA pathways converge on the nuclear transport factor RanBP1. Eur J Cell Biol 2024; 103:151376. [PMID: 38011756 DOI: 10.1016/j.ejcb.2023.151376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/01/2023] [Accepted: 11/17/2023] [Indexed: 11/29/2023] Open
Abstract
Nuclear protein trafficking requires the soluble transport factor RanBP1. The subcellular distribution of RanBP1 is dynamic, as the protein shuttles between the nucleus and cytoplasm. To date, the signaling pathways regulating RanBP1 subcellular localization are poorly understood. During interphase, RanBP1 resides mostly in the cytoplasm. We show here that oxidative stress concentrates RanBP1 in the nucleus, and our study defines the underlying mechanisms. Specifically, RanBP1's cysteine residues are not essential for its oxidant-induced relocation. Furthermore, our pharmacological approaches uncover that signaling mediated by epidermal growth factor receptor (EGFR) and protein kinase A (PKA) control RanBP1 localization during stress. In particular, pharmacological inhibitors of EGFR or PKA diminish the oxidant-dependent relocation of RanBP1. Mutant analysis identified serine 60 and tyrosine 103 as regulators of RanBP1 nuclear accumulation during oxidant exposure. Taken together, our results define RanBP1 as a target of oxidative stress and a downstream effector of EGFR and PKA signaling routes. This positions RanBP1 at the intersection of important cellular signaling circuits.
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Affiliation(s)
- Mohamed Kodiha
- Department of Physiology McGill University, Montreal H3G 1Y6, Canada
| | - Nabila Azad
- Department of Physiology McGill University, Montreal H3G 1Y6, Canada
| | - Siwei Chu
- Department of Physiology McGill University, Montreal H3G 1Y6, Canada
| | - Noah Crampton
- Department of Physiology McGill University, Montreal H3G 1Y6, Canada
| | - Ursula Stochaj
- Department of Physiology McGill University, Montreal H3G 1Y6, Canada.
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2
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Gerritsen JS, Faraguna JS, Bonavia R, Furnari FB, White FM. Predictive data-driven modeling of C-terminal tyrosine function in the EGFR signaling network. Life Sci Alliance 2023; 6:e202201466. [PMID: 37169593 PMCID: PMC10176108 DOI: 10.26508/lsa.202201466] [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: 03/28/2022] [Revised: 04/30/2023] [Accepted: 05/01/2023] [Indexed: 05/13/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) has been studied extensively because of its critical role in cellular signaling and association with disease. Previous models have elucidated interactions between EGFR and downstream adaptor proteins or showed phenotypes affected by EGFR. However, the link between specific EGFR phosphorylation sites and phenotypic outcomes is still poorly understood. Here, we employed a suite of isogenic cell lines expressing site-specific mutations at each of the EGFR C-terminal phosphorylation sites to interrogate their role in the signaling network and cell biological response to stimulation. Our results demonstrate the resilience of the EGFR network, which was largely similar even in the context of multiple Y-to-F mutations in the EGFR C-terminal tail, while also revealing nodes in the network that have not previously been linked to EGFR signaling. Our data-driven model highlights the signaling network nodes associated with distinct EGF-driven cell responses, including migration, proliferation, and receptor trafficking. Application of this same approach to less-studied RTKs should provide a plethora of novel associations that should lead to an improved understanding of these signaling networks.
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Affiliation(s)
- Jacqueline S Gerritsen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Joseph S Faraguna
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Rudy Bonavia
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
| | - Frank B Furnari
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
- Moores Cancer Center, University of California at San Diego, La Jolla, CA, USA
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Forest M White
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, MA, USA
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3
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Yeo AT, Shah R, Aliazis K, Pal R, Xu T, Zhang P, Rawal S, Rose CM, Varn FS, Appleman VA, Yoon J, Varma H, Gygi SP, Verhaak RG, Boussiotis VA, Charest A. Driver Mutations Dictate the Immunologic Landscape and Response to Checkpoint Immunotherapy of Glioblastoma. Cancer Immunol Res 2023; 11:629-645. [PMID: 36881002 PMCID: PMC10155040 DOI: 10.1158/2326-6066.cir-22-0655] [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: 08/14/2022] [Revised: 12/20/2022] [Accepted: 03/03/2023] [Indexed: 03/08/2023]
Abstract
The composition of the tumor immune microenvironment (TIME) is considered a key determinant of patients' response to immunotherapy. The mechanisms underlying TIME formation and development over time are poorly understood. Glioblastoma (GBM) is a lethal primary brain cancer for which there are no curative treatments. GBMs are immunologically heterogeneous and impervious to checkpoint blockade immunotherapies. Utilizing clinically relevant genetic mouse models of GBM, we identified distinct immune landscapes associated with expression of EGFR wild-type and mutant EGFRvIII cancer driver mutations. Over time, accumulation of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) was more pronounced in EGFRvIII-driven GBMs and was correlated with resistance to PD-1 and CTLA-4 combination checkpoint blockade immunotherapy. We determined that GBM-secreted CXCL1/2/3 and PMN-MDSC-expressed CXCR2 formed an axis regulating output of PMN-MDSCs from the bone marrow leading to systemic increase in these cells in the spleen and GBM tumor-draining lymph nodes. Pharmacologic targeting of this axis induced a systemic decrease in the numbers of PMN-MDSC, facilitated responses to PD-1 and CTLA-4 combination checkpoint blocking immunotherapy, and prolonged survival in mice bearing EGFRvIII-driven GBM. Our results uncover a relationship between cancer driver mutations, TIME composition, and sensitivity to checkpoint blockade in GBM and support the stratification of patients with GBM for checkpoint blockade therapy based on integrated genotypic and immunologic profiles.
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Affiliation(s)
- Alan T. Yeo
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Sackler School of Graduate Studies, Tufts University School of Medicine, Boston, Massachusetts
| | - Rushil Shah
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Konstantinos Aliazis
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Rinku Pal
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Tuoye Xu
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Piyan Zhang
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Shruti Rawal
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | | | - Frederick S. Varn
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut
| | - Vicky A. Appleman
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Joon Yoon
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Hemant Varma
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Steven P. Gygi
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Roel G.W. Verhaak
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut
| | - Vassiliki A. Boussiotis
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Al Charest
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
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4
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Wang BZ, Luo L, Vunjak-Novakovic G. RNA and Protein Delivery by Cell-Secreted and Bioengineered Extracellular Vesicles. Adv Healthc Mater 2022; 11:e2101557. [PMID: 34706168 PMCID: PMC8891029 DOI: 10.1002/adhm.202101557] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/28/2021] [Indexed: 12/22/2022]
Abstract
Extracellular vesicles (EVs) are carriers of biological signals through export and delivery of RNAs and proteins. Of increasing interest is the use of EVs as a platform for delivery of biomolecules. Preclinical studies have effectively used EVs to treat a number of diseases. Uniquely, endogenous machinery within cells can be manipulated in order to produce desirable loading of cargo within secreted EVs. In order to inform the development of such approaches, an understanding of the cellular mechanisms by which cargo is sorted to EVs is required. Here, the current knowledge of cargo sorting within EVs is reviewed. Here is given an overview of recent bioengineering approaches that leverage these advances. Methods of externally manipulating EV cargo are also discussed. Finally, a perspective on the current challenges of EVs as a drug delivery platform is offered. It is proposed that standardized bioengineering methods for therapeutic EV preparation will be required to create a well-defined clinical product.
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Affiliation(s)
- Bryan Z. Wang
- Department of Biomedical Engineering, 622 West 168th Street VC12-234, 10032, U.S.A
- Department of Medicine, 622 West 168th Street VC12-234, 10032, U.S.A
| | - Lori Luo
- Department of Medicine, 622 West 168th Street VC12-234, 10032, U.S.A
| | - Gordana Vunjak-Novakovic
- Department of Biomedical Engineering, 622 West 168th Street VC12-234, 10032, U.S.A
- Department of Medicine, 622 West 168th Street VC12-234, 10032, U.S.A
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5
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Expanding the Disorder-Function Paradigm in the C-Terminal Tails of Erbbs. Biomolecules 2021; 11:biom11111690. [PMID: 34827688 PMCID: PMC8615588 DOI: 10.3390/biom11111690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/03/2021] [Accepted: 11/10/2021] [Indexed: 12/16/2022] Open
Abstract
ErbBs are receptor tyrosine kinases involved not only in development, but also in a wide variety of diseases, particularly cancer. Their extracellular, transmembrane, juxtamembrane, and kinase folded domains were described extensively over the past 20 years, structurally and functionally. However, their whole C-terminal tails (CTs) following the kinase domain were only described at atomic resolution in the last 4 years. They were shown to be intrinsically disordered. The CTs are known to be tyrosine-phosphorylated when the activated homo- or hetero-dimers of ErbBs are formed. Their phosphorylation triggers interaction with phosphotyrosine binding (PTB) or Src Homology 2 (SH2) domains and activates several signaling pathways controling cellular motility, proliferation, adhesion, and apoptosis. Beyond this passive role of phosphorylated domain and site display for partners, recent structural and function studies unveiled active roles in regulation of phosphorylation and interaction: the CT regulates activity of the kinase domain; different phosphorylation states have different compaction levels, potentially modulating the succession of phosphorylation events; and prolines have an important role in structure, dynamics, and possibly regulatory interactions. Here, we review both the canonical role of the disordered CT domains of ErbBs as phosphotyrosine display domains and the recent findings that expand the known range of their regulation functions linked to specific structural and dynamic features.
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6
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Maxwell MJ, Arnold A, Sweeney H, Chen L, Lih TSM, Schnaubelt M, Eberhart CG, Rubens JA, Zhang H, Clark DJ, Raabe EH. Unbiased Proteomic and Phosphoproteomic Analysis Identifies Response Signatures and Novel Susceptibilities After Combined MEK and mTOR Inhibition in BRAF V600E Mutant Glioma. Mol Cell Proteomics 2021; 20:100123. [PMID: 34298159 PMCID: PMC8363840 DOI: 10.1016/j.mcpro.2021.100123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/01/2021] [Accepted: 07/16/2021] [Indexed: 11/24/2022] Open
Abstract
The mitogen-activated protein kinase pathway is one of the most frequently altered pathways in cancer. It is involved in the control of cell proliferation, invasion, and metabolism, and can cause resistance to therapy. A number of aggressive malignancies, including melanoma, colon cancer, and glioma, are driven by a constitutively activating missense mutation (V600E) in the v-Raf murine sarcoma viral oncogene homolog B (BRAF) component of the pathway. Mitogen-activated protein kinase kinase (MEK) inhibition is initially effective in targeting these cancers, but reflexive activation of mammalian target of rapamycin (mTOR) signaling contributes to frequent therapy resistance. We have previously demonstrated that combination treatment with the MEK inhibitor trametinib and the dual mammalian target of rapamycin complex 1/2 inhibitor TAK228 improves survival and decreases vascularization in a BRAFV600E mutant glioma model. To elucidate the mechanism of action of this combination therapy and understand the ensuing tumor response, we performed comprehensive unbiased proteomic and phosphoproteomic characterization of BRAFV600E mutant glioma xenografts after short-course treatment with trametinib and TAK228. We identified 13,313 proteins and 30,928 localized phosphosites, of which 12,526 proteins and 17,444 phosphosites were quantified across all samples (data available via ProteomeXchange; identifier PXD022329). We identified distinct response signatures for each monotherapy and combination therapy and validated that combination treatment inhibited activation of the mitogen-activated protein kinase and mTOR pathways. Combination therapy also increased apoptotic signaling, suppressed angiogenesis signaling, and broadly suppressed the activity of the cyclin-dependent kinases. In response to combination therapy, both epidermal growth factor receptor and class 1 histone deacetylase proteins were activated. This study reports a detailed (phospho)proteomic analysis of the response of BRAFV600E mutant glioma to combined MEK and mTOR pathway inhibition and identifies new targets for the development of rational combination therapies for BRAF-driven tumors.
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Affiliation(s)
- Micah J Maxwell
- Division of Pediatric Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
| | - Antje Arnold
- Division of Neuropathology, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Heather Sweeney
- Division of Pediatric Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Lijun Chen
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Tung-Shing M Lih
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael Schnaubelt
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Charles G Eberhart
- Division of Neuropathology, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jeffrey A Rubens
- Division of Pediatric Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hui Zhang
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - David J Clark
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Eric H Raabe
- Division of Pediatric Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Division of Neuropathology, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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7
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Mushtaq U, Bashir M, Nabi S, Khanday FA. Epidermal growth factor receptor and integrins meet redox signaling through P66shc and Rac1. Cytokine 2021; 146:155625. [PMID: 34157521 DOI: 10.1016/j.cyto.2021.155625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 05/23/2021] [Accepted: 06/08/2021] [Indexed: 12/24/2022]
Abstract
This review examines the concerted role of Epidermal Growth Factor Receptor (EGFR) and integrins in regulating Reactive oxygen species (ROS) production through different signaling pathways. ROS as such are not always deleterious to the cells but they also act as signaling molecules, that regulates numerous indespensible physiological fuctions of life. Many adaptor proteins, particularly Shc and Grb2, are involved in mediating the downstream signaling pathways stimulated by EGFR and integrins. Integrin-induced activation of EGFR and subsequent tyrosine phosphorylation of a class of acceptor sites on EGFR leads to alignment and tyrosine phosphorylation of Shc, PLCγ, the p85 subunit of PI-3 K, and Cbl, followed by activation of the downstream targets Erk and Akt/PKB. Functional interactions between these receptors result in the activation of Rac1 via these adaptor proteins, thereby leading to Reactive Oxygen Species. Both GF and integrin activation can produce oxidants independently, however synergistically there is increased ROS generation, suggesting a mutual cooperation between integrins and GFRs for redox signalling. The ROS produced further promotes feed-forward stimulation of redox signaling events such as MAPK activation and gene expression. This relationship has not been reviewed previously. The literature presented here can have multiple implications, ranging from looking at synergistic effects of integrin and EGFR mediated signaling mechanisms of different proteins to possible therapeutic interventions operated by these two receptors. Furthermore, such mutual redox regulation of crosstalk between EGFR and integrins not only add to the established models of pathological oxidative stress, but also can impart new avenues and opportunities for targeted antioxidant based therapeutics.
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Affiliation(s)
- Umar Mushtaq
- Department of Biotechnology, University of Kashmir, Srinagar, JK 190006, India; Department of Biotechnology, Central University of Kashmir, Ganderbal, JK 191201, India
| | - Muneesa Bashir
- Department of Biotechnology, University of Kashmir, Srinagar, JK 190006, India; Department of Higher Education, Government of Jammu & Kashmir, 190001, India
| | - Sumaiya Nabi
- Department of Biochemistry, University of Kashmir, Srinagar, JK 190006, India
| | - Firdous A Khanday
- Department of Biotechnology, University of Kashmir, Srinagar, JK 190006, India.
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8
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Geskovski N, Matevska-Geshkovska N, Dimchevska Sazdovska S, Glavas Dodov M, Mladenovska K, Goracinova K. The impact of molecular tumor profiling on the design strategies for targeting myeloid leukemia and EGFR/CD44-positive solid tumors. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:375-401. [PMID: 33981532 PMCID: PMC8093552 DOI: 10.3762/bjnano.12.31] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 04/12/2021] [Indexed: 05/21/2023]
Abstract
Nanomedicine has emerged as a novel cancer treatment and diagnostic modality, whose design constantly evolves towards increasing the safety and efficacy of the chemotherapeutic and diagnostic protocols. Molecular diagnostics, which create a great amount of data related to the unique molecular signatures of each tumor subtype, have emerged as an important tool for detailed profiling of tumors. They provide an opportunity to develop targeting agents for early detection and diagnosis, and to select the most effective combinatorial treatment options. Alongside, the design of the nanoscale carriers needs to cope with novel trends of molecular screening. Also, multiple targeting ligands needed for robust and specific interactions with the targeted cell populations have to be introduced, which should result in substantial improvements in safety and efficacy of the cancer treatment. This article will focus on novel design strategies for nanoscale drug delivery systems, based on the unique molecular signatures of myeloid leukemia and EGFR/CD44-positive solid tumors, and the impact of novel discoveries in molecular tumor profiles on future chemotherapeutic protocols.
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Affiliation(s)
- Nikola Geskovski
- Institute of Pharmaceutical Technology, Faculty of Pharmacy, University of Ss. Cyril and Methodius in Skopje, Skopje, North Macedonia
| | - Nadica Matevska-Geshkovska
- Center for Pharmaceutical Biomolecular Analyses, Faculty of Pharmacy, University of Ss. Cyril and Methodius in Skopje, Skopje, North Macedonia
| | - Simona Dimchevska Sazdovska
- Institute of Pharmaceutical Technology, Faculty of Pharmacy, University of Ss. Cyril and Methodius in Skopje, Skopje, North Macedonia
- Department of Nanobiotechnology, Institute of Biotechnology, Brandenburg University of Technology Cottbus-Senftenberg, Senftenberg, Germany
| | - Marija Glavas Dodov
- Institute of Pharmaceutical Technology, Faculty of Pharmacy, University of Ss. Cyril and Methodius in Skopje, Skopje, North Macedonia
| | - Kristina Mladenovska
- Institute of Pharmaceutical Technology, Faculty of Pharmacy, University of Ss. Cyril and Methodius in Skopje, Skopje, North Macedonia
| | - Katerina Goracinova
- Institute of Pharmaceutical Technology, Faculty of Pharmacy, University of Ss. Cyril and Methodius in Skopje, Skopje, North Macedonia
- College of Pharmacy, Qatar University, PO Box 2713, Doha, Qatar
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9
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Atukorala I, Mathivanan S. The Role of Post-Translational Modifications in Targeting Protein Cargo to Extracellular Vesicles. Subcell Biochem 2021; 97:45-60. [PMID: 33779913 DOI: 10.1007/978-3-030-67171-6_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Extracellular vesicles (EVs) are naturally occurring nanoparticles that contain proteins and nucleic acids. It is speculated that cells release EVs loaded with a selective cargo of proteins through highly regulated processes. Several proteomic and biochemical studies have highlighted phosphorylated, glycosylated, ubiquitinated, SUMOylated, oxidated and palmitoylated proteins within the EVs. Emerging evidences suggest that post-translational modifications (PTMs) can regulate the sorting of specific proteins into EVs and such proteins with specific PTMs have also been identified in clinical samples. Hence, it has been proposed that EV proteins with PTMs could be used as potential biomarkers of disease conditions. Among the other cellular mechanisms, the endosomal sorting complex required for transport (ESCRT) is also implicated in cargo sorting into EVs. In this chapter, various PTMs that are shown to regulate protein cargo sorting into EVs will be discussed.
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Affiliation(s)
- Ishara Atukorala
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia.
| | - Suresh Mathivanan
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
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10
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Mota STS, Vecchi L, Alves DA, Cordeiro AO, Guimarães GS, Campos-Fernández E, Maia YCP, Dornelas BDC, Bezerra SM, de Andrade VP, Goulart LR, Araújo TG. Annexin A1 promotes the nuclear localization of the epidermal growth factor receptor in castration-resistant prostate cancer. Int J Biochem Cell Biol 2020; 127:105838. [PMID: 32858191 DOI: 10.1016/j.biocel.2020.105838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/30/2020] [Accepted: 08/20/2020] [Indexed: 12/24/2022]
Abstract
Epidermal growth factor receptor is a cancer driver whose nuclear localization has been associated with the progression of prostate cancer to the castration-resistant phenotype. Previous reports indicated a functional interaction between this receptor and the protein Annexin A1, which has also been associated with aggressive tumors. The molecular pathogenesis of castration-resistant prostate cancer remains largely unresolved, and herein we have demonstrated the correlation between the expression levels and localization of the epidermal growth factor receptor and Annexin A1 in prostate cancer samples and cell lines. Interestingly, a higher expression of both proteins was detected in castration-resistant prostate cancer cell lines and the strongest correlation was seen at the nuclear level. We verified that Annexin A1 interacts with the epidermal growth factor receptor, and by using prostate cancer cell lines knocked down for Annexin A1, we succeeded in demonstrating that Annexin A1 promotes the nuclear localization of epidermal growth factor receptor. Finally, we showed that Annexin A1 activates an autocrine signaling in castration-resistant prostate cells through the formyl peptide receptor 1. The inhibition of such signaling by Cyclosporin H inhibits the nuclear localization of epidermal growth factor receptor and its downstream signaling. The present work sheds light on the functional interaction between nuclear epidermal growth factor receptor and nuclear Annexin A1 in castration-resistant prostate cancer. Therefore, strategies to inhibit the nuclear localization of epidermal growth factor receptor through the suppression of the Annexin A1 autocrine loop could represent an important intervention strategy for castration-resistant prostate cancer.
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Affiliation(s)
- Sara Teixeira Soares Mota
- Laboratory of Genetics and Biotechnology, Institute of Biotechnology, Federal University of Uberlandia, Patos de Minas, MG, 387400-128, Brazil; Laboratory of Nanobiotechnology, Institute of Biotechnology, Federal University of Uberlandia, Uberlandia, MG, 38400-902, Brazil.
| | - Lara Vecchi
- Laboratory of Nanobiotechnology, Institute of Biotechnology, Federal University of Uberlandia, Uberlandia, MG, 38400-902, Brazil.
| | - Douglas Alexsander Alves
- Laboratory of Genetics and Biotechnology, Institute of Biotechnology, Federal University of Uberlandia, Patos de Minas, MG, 387400-128, Brazil; Laboratory of Nanobiotechnology, Institute of Biotechnology, Federal University of Uberlandia, Uberlandia, MG, 38400-902, Brazil.
| | - Antonielle Oliveira Cordeiro
- Laboratory of Genetics and Biotechnology, Institute of Biotechnology, Federal University of Uberlandia, Patos de Minas, MG, 387400-128, Brazil; Laboratory of Nanobiotechnology, Institute of Biotechnology, Federal University of Uberlandia, Uberlandia, MG, 38400-902, Brazil.
| | - Gabriela Silva Guimarães
- Laboratory of Genetics and Biotechnology, Institute of Biotechnology, Federal University of Uberlandia, Patos de Minas, MG, 387400-128, Brazil; Laboratory of Nanobiotechnology, Institute of Biotechnology, Federal University of Uberlandia, Uberlandia, MG, 38400-902, Brazil.
| | - Esther Campos-Fernández
- Laboratory of Nanobiotechnology, Institute of Biotechnology, Federal University of Uberlandia, Uberlandia, MG, 38400-902, Brazil.
| | | | - Bruno de Carvalho Dornelas
- Pathology Division, Internal Medicine, University Hospital, Federal University of Uberlandia, Uberlandia, MG, 38400-902, Brazil.
| | | | | | - Luiz Ricardo Goulart
- Laboratory of Genetics and Biotechnology, Institute of Biotechnology, Federal University of Uberlandia, Patos de Minas, MG, 387400-128, Brazil; University of California, Davis, Dept. of Medical Microbiology and Immunology, Davis, CA, 95616, USA.
| | - Thaise Gonçalves Araújo
- Laboratory of Genetics and Biotechnology, Institute of Biotechnology, Federal University of Uberlandia, Patos de Minas, MG, 387400-128, Brazil; Laboratory of Nanobiotechnology, Institute of Biotechnology, Federal University of Uberlandia, Uberlandia, MG, 38400-902, Brazil.
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11
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Rao TC, Ma VPY, Blanchard A, Urner TM, Grandhi S, Salaita K, Mattheyses AL. EGFR activation attenuates the mechanical threshold for integrin tension and focal adhesion formation. J Cell Sci 2020; 133:jcs238840. [PMID: 32546532 PMCID: PMC7358133 DOI: 10.1242/jcs.238840] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 06/04/2020] [Indexed: 02/06/2023] Open
Abstract
Mechanical forces, growth factors and the extracellular matrix all play crucial roles in cell adhesion. To understand how epidermal growth factor receptor (EGFR) impacts the mechanics of adhesion, we employed tension gauge tether (TGT) probes displaying the integrin ligand cRGDfK and quantified integrin tension. EGF exposure significantly increased spread area, cell circularity, integrated integrin tension, mechanical rupture density, radial organization and size of focal adhesions in Cos-7 cells on TGT surfaces. These findings suggest that EGFR regulates integrin tension and the spatial organization of focal adhesions. Additionally, we found that the mechanical tension threshold for outside-in integrin activation is tunable by EGFR. Parallel genetic and pharmacologic strategies demonstrated that these phenotypes are driven by ligand-dependent EGFR signaling. Our results establish a novel mechanism whereby EGFR regulates integrin activation and cell adhesion, providing control over cellular responses to the environment.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | | | - Aaron Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA
| | - Tara M Urner
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Shreya Grandhi
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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12
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Mauthe M, Orhon I, Rocchi C, Zhou X, Luhr M, Hijlkema KJ, Coppes RP, Engedal N, Mari M, Reggiori F. Chloroquine inhibits autophagic flux by decreasing autophagosome-lysosome fusion. Autophagy 2018; 14:1435-1455. [PMID: 29940786 PMCID: PMC6103682 DOI: 10.1080/15548627.2018.1474314] [Citation(s) in RCA: 1194] [Impact Index Per Article: 199.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 02/08/2023] Open
Abstract
Macroautophagy/autophagy is a conserved transport pathway where targeted structures are sequestered by phagophores, which mature into autophagosomes, and then delivered into lysosomes for degradation. Autophagy is involved in the pathophysiology of numerous diseases and its modulation is beneficial for the outcome of numerous specific diseases. Several lysosomal inhibitors such as bafilomycin A1 (BafA1), protease inhibitors and chloroquine (CQ), have been used interchangeably to block autophagy in in vitro experiments assuming that they all primarily block lysosomal degradation. Among them, only CQ and its derivate hydroxychloroquine (HCQ) are FDA-approved drugs and are thus currently the principal compounds used in clinical trials aimed to treat tumors through autophagy inhibition. However, the precise mechanism of how CQ blocks autophagy remains to be firmly demonstrated. In this study, we focus on how CQ inhibits autophagy and directly compare its effects to those of BafA1. We show that CQ mainly inhibits autophagy by impairing autophagosome fusion with lysosomes rather than by affecting the acidity and/or degradative activity of this organelle. Furthermore, CQ induces an autophagy-independent severe disorganization of the Golgi and endo-lysosomal systems, which might contribute to the fusion impairment. Strikingly, HCQ-treated mice also show a Golgi disorganization in kidney and intestinal tissues. Altogether, our data reveal that CQ and HCQ are not bona fide surrogates for other types of late stage lysosomal inhibitors for in vivo experiments. Moreover, the multiple cellular alterations caused by CQ and HCQ call for caution when interpreting results obtained by blocking autophagy with this drug.
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Affiliation(s)
- Mario Mauthe
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Cell Biology, University Medical Center Utrecht, Center for Molecular Medicine, Utrecht, The Netherlands
| | - Idil Orhon
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Cecilia Rocchi
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Xingdong Zhou
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, People’s Republic of China
| | - Morten Luhr
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership for Molecular Medicine, University of Oslo, Oslo, Norway
| | - Kerst-Jan Hijlkema
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Robert P. Coppes
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nikolai Engedal
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership for Molecular Medicine, University of Oslo, Oslo, Norway
| | - Muriel Mari
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Cell Biology, University Medical Center Utrecht, Center for Molecular Medicine, Utrecht, The Netherlands
| | - Fulvio Reggiori
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Cell Biology, University Medical Center Utrecht, Center for Molecular Medicine, Utrecht, The Netherlands
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13
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Gill K, Macdonald-Obermann JL, Pike LJ. Epidermal growth factor receptors containing a single tyrosine in their C-terminal tail bind different effector molecules and are signaling-competent. J Biol Chem 2017; 292:20744-20755. [PMID: 29074618 DOI: 10.1074/jbc.m117.802553] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 10/13/2017] [Indexed: 01/07/2023] Open
Abstract
The EGF receptor is a classic receptor tyrosine kinase. It contains nine tyrosines in its C-terminal tail, many of which are phosphorylated and bind proteins containing SH2 or phosphotyrosine-binding (PTB) domains. To determine how many and which tyrosines are required to enable EGF receptor-mediated signaling, we generated a series of EGF receptors that contained only one tyrosine in their C-terminal tail. Assays of the signaling capabilities of these single-Tyr EGF receptors indicated that they can activate a range of downstream signaling pathways, including MAP kinase and Akt. The ability of the single-Tyr receptors to signal correlated with their ability to bind Gab1 (Grb2-associated binding protein 1). However, Tyr-992 appeared to be almost uniquely required to observe activation of phospholipase Cγ. These results demonstrate that multiply phosphorylated receptors are not required to support most EGF-stimulated signaling but identify Tyr-992 and its binding partners as a unique node within the network. We also studied the binding of the isolated SH2 domain of Grb2 (growth factor receptor-bound protein 2) and the isolated PTB domain of Shc (SHC adaptor protein) to the EGF receptor. Although these adapter proteins bound readily to wild-type EGF receptor, they bound poorly to the single-Tyr EGF receptors, even those that bound full-length Grb2 and Shc well. This suggests that in addition to pTyr-directed associations, secondary interactions between the tail and regions of the adapter proteins outside of the SH2/PTB domains are important for stabilizing the binding of Grb2 and Shc to the single-Tyr EGF receptors.
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Affiliation(s)
- Kamaldeep Gill
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Jennifer L Macdonald-Obermann
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Linda J Pike
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
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14
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Phosphoproteomics Reveals HMGA1, a CK2 Substrate, as a Drug-Resistant Target in Non-Small Cell Lung Cancer. Sci Rep 2017; 7:44021. [PMID: 28290473 PMCID: PMC5349541 DOI: 10.1038/srep44021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 02/03/2017] [Indexed: 12/13/2022] Open
Abstract
Although EGFR tyrosine kinase inhibitors (TKIs) have demonstrated good efficacy in non-small-cell lung cancer (NSCLC) patients harboring EGFR mutations, most patients develop intrinsic and acquired resistance. We quantitatively profiled the phosphoproteome and proteome of drug-sensitive and drug-resistant NSCLC cells under gefitinib treatment. The construction of a dose-dependent responsive kinase-substrate network of 1548 phosphoproteins and 3834 proteins revealed CK2-centric modules as the dominant core network for the potential gefitinib resistance-associated proteins. CK2 knockdown decreased cell survival in gefitinib-resistant NSCLCs. Using motif analysis to identify the CK2 core sub-network, we verified that elevated phosphorylation level of a CK2 substrate, HMGA1 was a critical node contributing to EGFR-TKI resistance in NSCLC cell. Both HMGA1 knockdown or mutation of the CK2 phosphorylation site, S102, of HMGA1 reinforced the efficacy of gefitinib in resistant NSCLC cells through reactivation of the downstream signaling of EGFR. Our results delineate the TKI resistance-associated kinase-substrate network, suggesting a potential therapeutic strategy for overcoming TKI-induced resistance in NSCLC.
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15
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Haake SM, Li J, Bai Y, Kinose F, Fang B, Welsh EA, Zent R, Dhillon J, Pow-Sang JM, Chen YA, Koomen JM, Rathmell WK, Fishman M, Haura EB. Tyrosine Kinase Signaling in Clear Cell and Papillary Renal Cell Carcinoma Revealed by Mass Spectrometry-Based Phosphotyrosine Proteomics. Clin Cancer Res 2016; 22:5605-5616. [PMID: 27220961 DOI: 10.1158/1078-0432.ccr-15-1673] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 04/11/2016] [Accepted: 04/12/2016] [Indexed: 12/29/2022]
Abstract
PURPOSE Targeted therapies in renal cell carcinoma (RCC) are limited by acquired resistance. Novel therapeutic targets are needed to combat resistance and, ideally, target the unique biology of RCC subtypes. EXPERIMENTAL DESIGN Tyrosine kinases provide critical oncogenic signaling and their inhibition has significantly impacted cancer care. To describe a landscape of tyrosine kinase activity in RCC that could inform novel therapeutic strategies, we performed a mass spectrometry-based system-wide survey of tyrosine phosphorylation in 10 RCC cell lines as well as 15 clear cell and 15 papillary RCC human tumors. To prioritize identified tyrosine kinases for further analysis, a 63 tyrosine kinase inhibitor (TKI) drug screen was performed. RESULTS Among the cell lines, 28 unique tyrosine phosphosites were identified across 19 kinases and phosphatases including EGFR, MET, JAK2, and FAK in nearly all samples. Multiple FAK TKIs decreased cell viability by at least 50% and inhibited RCC cell line adhesion, invasion, and proliferation. Among the tumors, 49 unique tyrosine phosphosites were identified across 44 kinases and phosphatases. FAK pY576/7 was found in all tumors and many cell lines, whereas DDR1 pY792/6 was preferentially enriched in the papillary RCC tumors. Both tyrosine kinases are capable of transmitting signals from the extracellular matrix and emerged as novel RCC therapeutic targets. CONCLUSIONS Tyrosine kinase profiling informs novel therapeutic strategies in RCC and highlights the unique biology among kidney cancer subtypes. Clin Cancer Res; 22(22); 5605-16. ©2016 AACR.
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Affiliation(s)
- Scott M Haake
- Division of Hematology & Medical Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
| | - Jiannong Li
- Department of Thoracic Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Yun Bai
- Department of Thoracic Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Fumi Kinose
- Department of Thoracic Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Bin Fang
- Proteomics Core Facility, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Eric A Welsh
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Roy Zent
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee.,Division of Nephrology, Department of Medicine, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Jasreman Dhillon
- Department of Pathology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Julio M Pow-Sang
- Genitourinary Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Y Ann Chen
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - John M Koomen
- Chemical Biology and Molecular Medicine Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida.,Molecular Oncology Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - W Kimryn Rathmell
- Division of Hematology & Medical Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Mayer Fishman
- Genitourinary Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Eric B Haura
- Department of Thoracic Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida.
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16
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Abstract
Despite extensive study of the EGF receptor (EGFR) signaling network, the immediate posttranslational changes that occur in response to growth factor stimulation remain poorly characterized; as a result, the biological mechanisms underlying signaling initiation remain obscured. To address this deficiency, we have used a mass spectrometry-based approach to measure system-wide phosphorylation changes throughout the network with 10-s resolution in the 80 s after stimulation in response to a range of eight growth factor concentrations. Significant changes were observed on proteins far downstream in the network as early as 10 s after stimulation, indicating a system capable of transmitting information quickly. Meanwhile, canonical members of the EGFR signaling network fall into clusters with distinct activation patterns. Src homology 2 domain containing transforming protein (Shc) and phosphoinositol 3-kinase (PI3K) phosphorylation levels increase rapidly, but equilibrate within 20 s, whereas proteins such as Grb2-associated binder-1 (Gab1) and SH2-containing tyrosine phosphatase (SHP2) show slower, sustained increases. Proximity ligation assays reveal that Shc and Gab1 phosphorylation patterns are representative of separate timescales for physical association with the receptor. Inhibition of phosphatases with vanadate reveals site-specific regulatory mechanisms and also uncovers primed activating components in the network, including Src family kinases, whose inhibition affects only a subset of proteins within the network. The results presented highlight the complexity of signaling initiation and provide a window into exploring mechanistic hypotheses about receptor tyrosine kinase (RTK) biology.
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17
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Darr J, Klochendler A, Isaac S, Geiger T, Geiger T, Eden A. Phosphoproteomic analysis reveals Smarcb1 dependent EGFR signaling in Malignant Rhabdoid tumor cells. Mol Cancer 2015; 14:167. [PMID: 26370283 PMCID: PMC4570560 DOI: 10.1186/s12943-015-0439-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 08/31/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The SWI/SNF ATP dependent chromatin remodeling complex is a multi-subunit complex, conserved in eukaryotic evolution that facilitates nucleosomal re-positioning relative to the DNA sequence. In recent years the SWI/SNF complex has emerged to play a role in cancer development as various sub-units of the complex are found to be mutated in a variety of tumors. One core-subunit of the complex, which has been well established as a tumor suppressor gene is SMARCB1 (SNF5/INI1/BAF47). Mutation and inactivation of SMARCB1 have been identified as the underlying mechanism leading to Malignant Rhabdoid Tumors (MRT) and Atypical Teratoid/Rhabdoid Tumors (AT/RT), two highly aggressive forms of pediatric neoplasms. METHODS We present a phosphoproteomic study of Smarcb1 dependent changes in signaling networks. The SILAC (Stable Isotopic Labeling of Amino Acids in Cell Culture) protocol was used to quantify in an unbiased manner any changes in the phosphoproteomic profile of Smarcb1 deficient murine rhabdoid tumor cell lines following Smarcb1 stable re-expression and under different serum conditions. RESULTS This study illustrates broad changes in the regulation of multiple biological networks including cell cycle progression, chromatin remodeling, cytoskeletal regulation and focal adhesion. Specifically, we identify Smarcb1 dependent changes in phosphorylation and expression of the EGF receptor, demonstrate downstream signaling and show that inhibition of EGFR signaling specifically hinders the proliferation of Smarcb1 deficient cells. CONCLUSIONS These results support recent findings regarding the effectivity of EGFR inhibitors in hindering the proliferation of human MRT cells and demonstrate that activation of EGFR signaling in Rhabdoid tumors is SMARCB1 dependent.
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Affiliation(s)
- Jonatan Darr
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Agnes Klochendler
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Sara Isaac
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Tamar Geiger
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Tami Geiger
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Amir Eden
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
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18
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Zahari MS, Wu X, Blair BG, Pinto SM, Nirujogi RS, Jelinek CA, Malhotra R, Kim MS, Park BH, Pandey A. Activating Mutations in PIK3CA Lead to Widespread Modulation of the Tyrosine Phosphoproteome. J Proteome Res 2015; 14:3882-3891. [DOI: 10.1021/acs.jproteome.5b00302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Muhammad Saddiq Zahari
- McKusick-Nathans
Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway Street, Baltimore, Maryland 21205, United States
| | - Xinyan Wu
- McKusick-Nathans
Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway Street, Baltimore, Maryland 21205, United States
| | - Brian G. Blair
- The
Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University School of Medicine, 401 North Broadway Street, Baltimore, Maryland 21231, United States
| | - Sneha M. Pinto
- Institute of Bioinformatics, International
Tech Park, Bangalore, 560066 India
| | - Raja S. Nirujogi
- Institute of Bioinformatics, International
Tech Park, Bangalore, 560066 India
| | - Christine A. Jelinek
- McKusick-Nathans
Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway Street, Baltimore, Maryland 21205, United States
| | - Radhika Malhotra
- College
of Arts and Sciences, University of Delaware, 4 Kent Way, Newark, Delaware 19716, United States
| | - Min-Sik Kim
- McKusick-Nathans
Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway Street, Baltimore, Maryland 21205, United States
| | - Ben Ho Park
- The
Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University School of Medicine, 401 North Broadway Street, Baltimore, Maryland 21231, United States
| | - Akhilesh Pandey
- McKusick-Nathans
Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway Street, Baltimore, Maryland 21205, United States
- Departments
of Oncology and Pathology, Johns Hopkins University School of Medicine, 401 North Broadway Street, Baltimore, Maryland 21231, United States
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19
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Lin C, Ear J, Midde K, Lopez-Sanchez I, Aznar N, Garcia-Marcos M, Kufareva I, Abagyan R, Ghosh P. Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin. Mol Biol Cell 2014; 25:3654-71. [PMID: 25187647 PMCID: PMC4230624 DOI: 10.1091/mbc.e14-05-0978] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
GIV, a guanidine exchange factor for trimeric Gi, contains a unique domain that functions like a SH2 domain. GIV's SH2-like domain binds autophosphorylated RTKs. Binding of GIV's SH2 to RTKs enables the receptors to activate trimeric Gi. Inhibition of GIV:RTK interaction abolishes GIV-dependent Akt enhancement downstream of RTKs. A long-standing issue in the field of signal transduction is to understand the cross-talk between receptor tyrosine kinases (RTKs) and heterotrimeric G proteins, two major and distinct signaling hubs that control eukaryotic cell behavior. Although stimulation of many RTKs leads to activation of trimeric G proteins, the molecular mechanisms behind this phenomenon remain elusive. We discovered a unifying mechanism that allows GIV/Girdin, a bona fide metastasis-related protein and a guanine-nucleotide exchange factor (GEF) for Gαi, to serve as a direct platform for multiple RTKs to activate Gαi proteins. Using a combination of homology modeling, protein–protein interaction, and kinase assays, we demonstrate that a stretch of ∼110 amino acids within GIV C-terminus displays structural plasticity that allows folding into a SH2-like domain in the presence of phosphotyrosine ligands. Using protein–protein interaction assays, we demonstrated that both SH2 and GEF domains of GIV are required for the formation of a ligand-activated ternary complex between GIV, Gαi, and growth factor receptors and for activation of Gαi after growth factor stimulation. Expression of a SH2-deficient GIV mutant (Arg 1745→Leu) that cannot bind RTKs impaired all previously demonstrated functions of GIV—Akt enhancement, actin remodeling, and cell migration. The mechanistic and structural insights gained here shed light on the long-standing questions surrounding RTK/G protein cross-talk, set a novel paradigm, and characterize a unique pharmacological target for uncoupling GIV-dependent signaling downstream of multiple oncogenic RTKs.
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Affiliation(s)
- Changsheng Lin
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| | - Jason Ear
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| | - Krishna Midde
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| | | | - Nicolas Aznar
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| | - Mikel Garcia-Marcos
- Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, CA 92093
| | - Irina Kufareva
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Ruben Abagyan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Pradipta Ghosh
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
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20
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Singla S, Pippin JA, Drebin JA. Dual ErbB1 and ErbB2 receptor tyrosine kinase inhibition exerts synergistic effect with conventional chemotherapy in pancreatic cancer. Oncol Rep 2012; 28:2211-6. [PMID: 23007710 DOI: 10.3892/or.2012.2053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 07/09/2012] [Indexed: 11/05/2022] Open
Abstract
Patient survival in pancreatic cancer remains poor with gemcitabine (GEM)-based regimens. The target specific molecular agent lapatinib, a dual ErbB1 and ErbB2 receptor tyrosine kinase inhibitor, has shown significant activity against ErbB1 and ErbB2-expressing tumors. Since pancreatic tumors frequently overexpress these proteins, we investigated its effects, both alone and in conjunction with 5-FU or GEM. The pancreatic cancer cell lines PANC-1 and AsPC were treated with varying doses of lapatinib in vitro. The effects on ErbB1/ErbB2 protein phosphorylation and on the cell survival protein survivin were determined by western blotting. Cytotoxicity was determined by MTT assay and apoptosis was measured using the caspase-3 colorimetric assay. Similar dose-response lapatinib experiments were conducted with varying concentrations of 5-FU or GEM and isobolograms were constructed to evaluate therapeutic synergy. Lapatinib inhibited protein phosphorylation in the range of 4-16 µM, a clinically achievable concentration. The lapatinib-treated cells showed a dose-dependent inhibition of cell proliferation and induction of apoptosis at the same concentrations that blocked ErbB1/ErbB2 phosphorylation. The addition of 5-FU or GEM to these cells resulted in synergistic effects. The lapatinib-treated cells also demonstrated downregulation of survivin. Simultaneous dual ErbB1 and ErbB2 receptor tyrosine kinase inhibition with lapatinib results in significant reduction of pancreatic cancer cell growth and proliferation. These effects occur at clinically achievable concentrations and are synergistic with the effects of 5-FU or GEM. These findings support the potential role of lapatinib in the treatment of pancreatic cancer.
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Affiliation(s)
- Smit Singla
- Department of Surgery, Temple University Hospital, Philadelphia, PA 19104, USA.
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21
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Pokorski JK, Hovlid ML, Finn MG. Cell targeting with hybrid Qβ virus-like particles displaying epidermal growth factor. Chembiochem 2011; 12:2441-7. [PMID: 21956837 DOI: 10.1002/cbic.201100469] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Indexed: 11/06/2022]
Abstract
Structurally uniform protein nanoparticles derived from the self-assembly of viral capsid proteins are attractive platforms for the multivalent display of cell-targeting motifs for use in nanomedicine. Virus-based nanoparticles are of particular interest because the scaffold can be manipulated both genetically and chemically to simultaneously display targeting groups and carry a functional payload. Here, we displayed the human epidermal growth factor (EGF) on the exterior surface of bacteriophage Qβ as a C-terminal genetic fusion to the Qβ capsid protein. The co-assembly of wild-type Qβ and EGF-modified subunits resulted in structurally homogeneous nanoparticles displaying between 5 and 12 copies of EGF on their exterior surface. The particles were found to be amenable to bioconjugation by standard methods as well as the high-fidelity copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC). Such chemical derivatization did not impair the ability of the particles to specifically interact with the EGF receptor. Additionally, the particle-displayed EGF remained biologically active promoting autophosphorylation of the EGF receptor and apoptosis of A431 cells. These results suggest that hybrid Qβ-EGF nanoparticles could be useful vehicles for targeted delivery of imaging and/or therapeutic agents.
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Affiliation(s)
- Jonathan K Pokorski
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
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22
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Yamaoka T, Frey MR, Dise RS, Bernard JK, Polk DB. Specific epidermal growth factor receptor autophosphorylation sites promote mouse colon epithelial cell chemotaxis and restitution. Am J Physiol Gastrointest Liver Physiol 2011; 301:G368-76. [PMID: 21617115 PMCID: PMC3154598 DOI: 10.1152/ajpgi.00327.2010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Upon ligand binding, epidermal growth factor (EGF) receptor (R) autophosphorylates on COOH-terminal tyrosines, generating docking sites for signaling partners that stimulate proliferation, restitution, and chemotaxis. Specificity for individual EGFR tyrosines in cellular responses has been hypothesized but not well documented. Here we tested the requirement for particular tyrosines, and associated downstream pathways, in mouse colon epithelial cell chemotactic migration. We compared these requirements to those for the phenotypically distinct restitution (wound healing) migration. Wild-type, Y992/1173F, Y1045F, Y1068F, and Y1086F EGFR constructs were expressed in EGFR(-/-) cells; EGF-induced chemotaxis or restitution were determined by Boyden chamber or modified scratch wound assay, respectively. Pharmacological inhibitors of p38, phospholipase C (PLC), Src, MEK, JNK/SAPK, phosphatidylinositol 3-kinase (PI 3-kinase), and protein kinase C (PKC) were used to block EGF-stimulated signaling. Pathway activation was determined by immunoblot analysis. Unlike wild-type EGFR, Y992/1173F and Y1086F EGFR did not stimulate colon epithelial cell chemotaxis toward EGF; Y1045F and Y1068F EGFR partially stimulated chemotaxis. Only wild-type EGFR promoted colonocyte restitution. Inhibition of p38, PLC, and Src, or Grb2 knockdown, blocked chemotaxis; JNK, PI 3-kinase, and PKC inhibitors or c-Cbl knockdown blocked restitution but not chemotaxis. All four EGFR mutants stimulated downstream signaling in response to EGF, but Y992/1173F EGFR was partially defective in PLCγ activation whereas both Y1068F and Y1086F EGFR failed to activate Src. We conclude that specific EGFR tyrosines play key roles in determining cellular responses to ligand. Chemotaxis and restitution, which have different migration phenotypes and physiological consequences, have overlapping but not identical EGFR signaling requirements.
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Affiliation(s)
- Toshimitsu Yamaoka
- 1Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition and
| | - Mark R. Frey
- 3Department of Pediatrics, Division of Gastroenterology and Nutrition and ,4Department of Biochemistry and Molecular Biology, University of Southern California Keck School of Medicine and The Saban Research Institute of Children's Hospital Los Angeles, Los Angeles, California
| | - Rebecca S. Dise
- 2Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Jessica K. Bernard
- 3Department of Pediatrics, Division of Gastroenterology and Nutrition and
| | - D. Brent Polk
- 1Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition and ,2Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee; and ,3Department of Pediatrics, Division of Gastroenterology and Nutrition and ,4Department of Biochemistry and Molecular Biology, University of Southern California Keck School of Medicine and The Saban Research Institute of Children's Hospital Los Angeles, Los Angeles, California
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23
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Astrocytic transactivation by α2A-adrenergic and 5-HT2B serotonergic signaling. Neurochem Int 2010; 57:421-31. [DOI: 10.1016/j.neuint.2010.04.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 03/24/2010] [Accepted: 04/28/2010] [Indexed: 12/11/2022]
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Du T, Li B, Li H, Li M, Hertz L, Peng L. Signaling pathways of isoproterenol-induced ERK1/2 phosphorylation in primary cultures of astrocytes are concentration-dependent. J Neurochem 2010; 115:1007-23. [PMID: 20831657 DOI: 10.1111/j.1471-4159.2010.06995.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Stimulation of β-adrenoceptors activates the canonical adenylate cyclase pathway (via G(s) protein) but can also evoke phosphorylation of extracellular-regulated kinases 1 and 2 (ERK(1/2) ) via G(s)/G(i) switching or β-arrestin-mediated recruitment of Src. In primary cultures of mouse astrocytes, activation of the former of these pathways required micromolar concentrations of the β(1)/β(2) -adrenergic agonist isoproterenol, that acted on β(1)-adrenoceptors, whereas the latter was activated already by nanomolar concentrations, acting on β(2) receptors. Protein kinase A activity was required for G(s)/G(i) switching, which was followed by Ca(2+) release from intracellular stores and G(iα)- and metalloproteinase-dependent transactivation of the epidermal growth factor receptor (EGFR; at its Y1173 phophorylation site), via its receptor-tyrosine kinase, β-arrestin 1/2 recruitment, and MAPK/ERK kinase-dependent ERK(1/2) phosphorylation. ERK(1/2) phosphorylation by Src activation depended on β-arrestin 2, but not β-arrestin 1, was accompanied by Src/EGFR co-precipitation and phosphorylation of the EGFR at the Src-phosphorylated Y845 site and the Y1045 autophosphorylation site; it was independent of transactivation but dependent on MAPK/ERK kinase activity, suggesting EGFR phosphorylation independently of the receptor-tyrosine kinase or activation of Ras or Raf directly from Src. Most astrocytic consequences of activating either pathway (or both) are unknown, but morphological differentiation and increase in glial fibrillary acidic protein in response to dibutyryl cAMP-mediated increase in cAMP depend on G(s)/G(i) switching and transactivation.
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Affiliation(s)
- Ting Du
- Department of Clinical Pharmacology, China Medical University, Shenyang, China
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Mäusbacher N, Schreiber TB, Daub H. Glycoprotein capture and quantitative phosphoproteomics indicate coordinated regulation of cell migration upon lysophosphatidic acid stimulation. Mol Cell Proteomics 2010; 9:2337-53. [PMID: 20639409 DOI: 10.1074/mcp.m110.000737] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The lipid mediator lysophosphatidic acid (LPA) is a serum component that regulates cellular functions such as proliferation, migration, and survival via specific G protein-coupled receptors. The underlying signaling mechanisms are still incompletely understood, including those that operate at the plasma membrane to modulate cell-cell and cell-matrix interactions in LPA-promoted cell migration. To explore LPA-evoked phosphoregulation with a focus on cell surface proteins, we combined glycoproteome enrichment by immobilized lectins with SILAC-based quantitative phosphoproteomics. We performed biological replicate analyses in SCC-9 squamous cell carcinoma cells and repeatedly quantified the effect of 1.5- and 5-min LPA treatment on more than 700 distinct phosphorylations in lectin-purified proteins. We detected many regulated phosphorylation events on various types of plasma membrane proteins such as cell adhesion molecules constituting adherens junctions, desmosomes, and hemidesmosomes. Several of these LPA-regulated phosphorylation sites have been characterized in a biological context other than G protein-coupled receptor signaling, and the transfer of this functional information suggests coordinated and multifactorial cell adhesion control in LPA-induced cell migration. Additionally, we identified LPA-mediated activation loop phosphorylation of the serine/threonine kinase Wnk1 and verified a role of Wnk1 for LPA-induced cell migration in knock-down experiments. In conclusion, the glycoproteome phosphoproteomics strategy described here sheds light on incompletely understood mechanisms in LPA-induced cell migratory behavior.
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Affiliation(s)
- Nina Mäusbacher
- Project Group Cell Signaling, Department of Molecular Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Germany
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26
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Frosi Y, Anastasi S, Ballarò C, Varsano G, Castellani L, Maspero E, Polo S, Alemà S, Segatto O. A two-tiered mechanism of EGFR inhibition by RALT/MIG6 via kinase suppression and receptor degradation. ACTA ACUST UNITED AC 2010; 189:557-71. [PMID: 20421427 PMCID: PMC2867293 DOI: 10.1083/jcb.201002032] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The EGFR kinase inhibitor RALT/MIG6 also functions as an endocytic adaptor to promote receptor internalization by scaffolding AP-2 and intersectins. Signaling by epidermal growth factor receptor (EGFR) must be controlled tightly because aberrant EGFR activity may cause cell transformation. Receptor-associated late transducer (RALT) is a feedback inhibitor of EGFR whose genetic ablation in the mouse causes phenotypes due to EGFR-driven excess cell proliferation. RALT inhibits EGFR catalytic activation by docking onto EGFR kinase domain. We report here an additional mechanism of EGFR suppression mediated by RALT, demonstrating that RALT-bound EGF receptors undergo endocytosis and eventual degradation into lysosomes. Moreover, RALT rescues the endocytic deficit of EGFR mutants unable to undergo either endocytosis (Dc214) or degradation (Y1045F) and mediates endocytosis via a domain distinct from that responsible for EGFR catalytic suppression. Consistent with providing a scaffolding function for endocytic proteins, RALT drives EGFR endocytosis by binding to AP-2 and Intersectins. These data suggest a model in which binding of RALT to EGFR integrates suppression of EGFR kinase with receptor endocytosis and degradation, leading to durable repression of EGFR signaling.
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Oliveira S, Schiffelers RM, van der Veeken J, van der Meel R, Vongpromek R, van Bergen En Henegouwen PMP, Storm G, Roovers RC. Downregulation of EGFR by a novel multivalent nanobody-liposome platform. J Control Release 2010; 145:165-75. [PMID: 20362020 DOI: 10.1016/j.jconrel.2010.03.020] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 03/18/2010] [Accepted: 03/24/2010] [Indexed: 10/19/2022]
Abstract
The epidermal growth factor receptor (EGFR) is a recognized target for tumor therapy and monoclonal antibodies (mAbs, e.g. cetuximab) have been developed to inhibit receptor activation. Besides blocking ligand (e.g. EGF) binding to the receptor, reports have shown that mAbs promote slow receptor internalization and degradation in lysosomes, i.e. downregulation. The efficacy of receptor downregulation was recently shown to depend on the size of receptor clusters formed at the cell surface. In this study, a multivalent platform is presented, consisting of nanobodies recognizing the ectodomain of EGFR (EGa1) coupled to PEG-liposomes, and the in vitro and in vivo effects of this system on EGFR internalization and downregulation were investigated. Nanobodies are the smallest functional antigen-binding immunoglobulin fragments and the EGa1 nanobody has been described as an EGFR-antagonist. EGa1-liposomes (EGa1-L) induced a more than 90% removal of EGFR from the cell surface, as a result of receptor internalization. Furthermore, this massive sequestration of EGFR mediated by EGa1-L lead to receptor degradation, while no degradation was detected with the monovalent nanobody. The downregulatory capacity here reported was found to be independent of the epitope on EGFR recognized by the grafted nanobody, and exclusive to the nanobody-liposomes, as anti-EGFR single chain variable fragments (scFv) coupled to liposomes were unable to induce this effect. Importantly, EGa1-L induced a significant inhibition of tumor cell proliferation, in vitro, an effect likely mediated by the combination of receptor downregulation and receptor antagonism. Also in vivo, EGFR downregulation was observed in tumors of mice intravenously injected with EGa1-L, indicating that this multivalent platform blocks ligand binding to the receptor and simultaneously induces the downregulation of EGFR.
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Affiliation(s)
- Sabrina Oliveira
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands
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28
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Angiopoietin-1-induced ubiquitylation of Tie2 by c-Cbl is required for internalization and degradation. Biochem J 2009; 423:375-80. [DOI: 10.1042/bj20091010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tie2 [where ‘Tie’ is an acronym from tyrosine kinase with Ig and EGF (epidermal growth factor) homology domains] is a receptor tyrosine kinase expressed predominantly on the surface of endothelial cells. Activated by its ligands, the angiopoietins, Tie2 initiates signalling pathways that modulate vascular stability and angiogenesis. Deletion of either the Tie2 or Ang1 (angiopoietin-1) gene in mice results in lethal vascular defects, signifying their importance in vascular development. The mechanism employed by the Tie2 signalling machinery to attenuate or cause receptor trafficking is not well defined. Stimulation of Tie2-expressing cells with Ang1 results in its ubiquitylation, suggesting that this may provide the necessary signal for receptor turnover. Using a candidate molecule approach, we demonstrate that Tie2 co-immunoprecipitates with c-Cbl in an Ang1-dependent manner and its ubiquitylation can be inhibited by the dominant-interfering molecule v-Cbl (a viral form of c-Cbl that contains only the tyrosine kinase-binding domain region). Inhibition of the Tie2–Cbl interaction by overexpression of v-Cbl blocks ligand-induced Tie2 internalization and degradation. In summary, our results illustrate that c-Cbl interacts with the Tie2 signalling complex in a stimulation-dependent manner, and that this interaction is required for Tie2 ubiquitylation, internalization and degradation.
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29
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Chong PK, Lee H, Kong JWF, Loh MCS, Wong CH, Lim YP. Phosphoproteomics, oncogenic signaling and cancer research. Proteomics 2008; 8:4370-82. [PMID: 18814326 DOI: 10.1002/pmic.200800051] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The past 5 years have seen an explosion of phosphoproteomics methods development. In this review, using epidermal growth-factor signaling as a model, we will discuss how phosphoproteomics, along with bioinformatics and computational modeling, have impacted key aspects of oncogenic signaling such as in the temporal fine mapping of phosphorylation events, and the identification of novel tyrosine kinase substrates and phosphorylation sites. We submit that the next decade will see considerable exploitation of phosphoproteomics in cancer research. Such a phenomenon is already happening as exemplified by its use in promoting the understanding of the molecular etiology of cancer and target-directed therapeutics.
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Affiliation(s)
- Poh-Kuan Chong
- Oncology Research Institute, Yong Loo Lin School of Medicine, Singapore
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30
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Busti S, Sacco E, Martegani E, Vanoni M. Functional coupling of the mammalian EGF receptor to the Ras/cAMP pathway in the yeast Saccharomyces cerevisiae. Curr Genet 2008; 53:153-62. [PMID: 18183397 DOI: 10.1007/s00294-007-0173-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2007] [Revised: 12/14/2007] [Accepted: 12/15/2007] [Indexed: 01/15/2023]
Abstract
Autophosphorylation of tyrosine residues on the cytoplasmic tail of the epidermal growth factor receptor (EGFR) upon ligand binding leads to recruitment of the Grb2/Sos complex to the activated receptor and to activation of the Ras pathway. The major aim of this study was to ascertain to which extent the EGFR module (receptor, Grb2, hSos1) could work in a lower eukaryote, completely devoid of tyrosine kinase receptors but possessing hortologues to mammalian Ras proteins. We show that the EGFR module can be functionally linked to the Ras/cAMP pathway in a Saccharomyces cerevisiae cdc25 ( ts ) strain, as monitored by several independent biological readouts, including drop of budding index, decrease of cAMP level and acquisition of thermotolerance. Autophosphorylation of the receptor is a necessary step for RTK-dependent activation of the yeast Ras pathway, since genetic and pharmacological downregulation of the EGFR catalytic activity abolish coupling with the Ras/cAMP pathway. Thus, our results newly indicate that a RTK-based signal transduction module can be functionally coupled to the yeast Ras/cAMP pathway and that our system can be a valuable tool for the screen of drugs inhibiting the kinase activity of the receptor.
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Affiliation(s)
- Stefano Busti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
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31
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Wang Q, Zhu F, Wang Z. Identification of EGF receptor C-terminal sequences 1005–1017 and di-leucine motif 1010LL1011 as essential in EGF receptor endocytosis. Exp Cell Res 2007; 313:3349-63. [PMID: 17643422 DOI: 10.1016/j.yexcr.2007.06.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 06/15/2007] [Accepted: 06/19/2007] [Indexed: 11/15/2022]
Abstract
Most studies regarding the role of epidermal growth factor (EGF) receptor (EGFR) C-terminal domain in EGFR internalization are done in the context of EGFR kinase activation. We recently showed that EGF-induced EGFR internalization is directly controlled by receptor dimerization, rather than kinase activation. Here we studied the role of EGFR C-terminus in EGF-induced EGFR internalization with or without EGFR kinase activation. We showed that graduate truncation of EGFR from C-terminus to 1044 did not affect EGF-induced EGFR endocytosis with or without kinase activation. However, truncation to 991 or further completely inhibited EGFR endocytosis. Graduate truncation within 991-1044 progressively lower EGF-induced EGFR endocytosis with most significant effects observed for residues 1005-1017. The endocytosis patterns of mutant EGFRs are independent of EGFR kinase activation. The residues 1005-1017 were also required for EGFR internalization triggered by non-ligand-induced receptor dimerization. This indicates that residues 1005-1017 function as an internalization motif, rather than a dimerization motif, to mediate EGFR internalization. Furthermore, we showed that the di-leucine motif 1010LL1011 within this region is essential in mediating EGF-induced rapid EGFR internalization independent of kinase activation. We conclude that EGFR C-terminal sequences 1005-1017 and the 1010LL1011 motif are essential for EGF-induced EGFR endoytosis independent of EGFR kinase activation and autophosphorylation.
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Affiliation(s)
- Qian Wang
- Department of Cell Biology and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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32
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Li N, Lorinczi M, Ireton K, Elferink LA. Specific Grb2-mediated interactions regulate clathrin-dependent endocytosis of the cMet-tyrosine kinase. J Biol Chem 2007; 282:16764-75. [PMID: 17449471 DOI: 10.1074/jbc.m610835200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lysosomal degradation of the receptor-tyrosine kinase cMet requires receptor ubiquitination by the E3 ubiquitin ligase Cbl followed by clathrin-dependent internalization. A role for Cbl as an adaptor for cMet internalization has been previously reported. However, the requirement for Cbl ubiquitin ligase activity in this process and its mode of recruitment to cMet has yet to be determined. Cbl can directly bind cMet at phosphotyrosine 1003 or indirectly via Grb2 to phosphotyrosine 1356 in the multisubstrate binding domain of cMet. The direct binding of Cbl with cMet is critical for receptor degradation and not receptor internalization. Here we show a strict requirement for Grb2 and the ubiquitin ligase activity of Cbl for cMet endocytosis. Receptor internalization was impaired by small interfering RNA depletion of Grb2, overexpression of dominant negative Grb2 mutants, and point mutations in the cMet multisubstrate docking site that inhibits the direct association of Grb2 with cMet. The requirement for Grb2 was specific and did not involve the multiadaptor Gab1. cMet internalization was impaired in cells expressing an ubiquitin ligase-deficient Cbl mutant or conjugation-deficient ubiquitin but was unaffected in cells expressing a Cbl mutant that is unable to bind cMet directly. Expression of a Cbl-Grb2 chimera rescued impaired cMet endocytosis in cells depleted of endogenous Grb2. These results indicate that the ubiquitin ligase activity of Cbl is critical for clathrin-dependent cMet internalization and suggest a role for Grb2 as an intermediary linking Cbl ubiquitin ligase activity to this process.
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Affiliation(s)
- Ning Li
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555-1074, USA
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33
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Merritt R, Hayman MJ, Agazie YM. Mutation of Thr466 in SHP2 abolishes its phosphatase activity, but provides a new substrate-trapping mutant. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2005; 1763:45-56. [PMID: 16413071 DOI: 10.1016/j.bbamcr.2005.11.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 11/08/2005] [Accepted: 11/11/2005] [Indexed: 11/21/2022]
Abstract
Most classical phosphotyrosyl phosphatases (PTPs), including the Src homology phosphotyrosyl phosphatase 2 (SHP2) possess a Thr or a Ser residue immediately C-terminal to the invariant Arg in the active site consensus motif (H/V-C-X5-R-S/T), also known as the "signature motif". SHP2 has a Thr (Thr466) at this position, but its importance in catalysis has not been investigated. By employing site-directed mutagenesis, phosphatase assays and substrate-trapping studies, we demonstrate that Thr466 is critical for the catalytic activity of SHP2. Its mutation to Ala abolishes phosphatase activity, but provides a new substrate-trapping mutant. We further show that the nucleophilic Cys459 is not involved in substrate trapping by Thr466Ala-SHP2 (T/A-SHP2). Mutation of Thr466 does not cause significant structural changes in the active site as revealed by the trapping of the epidermal growth factor receptor (EGFR), the physiological substrate of SHP2, and by orthovanadate competition experiments. Based on these results and previous other works, we propose that the role of Thr466 in the catalytic process of SHP2 could be stabilizing the sulfhydryl group of Cys459 in its reduced state, a state that enables nucleophilic attack on the phosphate moiety of the substrate. The T/A-SHP2 harbors a single mutation and specifically interacts with the EGFR. Since the nucleophilic Cys459 and the proton donor Asp425 are intact in the T/A-SAHP2, it offers an excellent starting material for solving the structure of SHP2 in complex with its physiological substrate.
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Affiliation(s)
- Rebecca Merritt
- Department of Biochemistry and Molecular Pharmacology and The Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506-9142, USA
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Thelemann A, Petti F, Griffin G, Iwata K, Hunt T, Settinari T, Fenyo D, Gibson N, Haley JD. Phosphotyrosine Signaling Networks in Epidermal Growth Factor Receptor Overexpressing Squamous Carcinoma Cells. Mol Cell Proteomics 2005; 4:356-76. [PMID: 15657067 DOI: 10.1074/mcp.m400118-mcp200] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Overexpression and enhanced activation of the epidermal growth factor (EGF) receptor are frequent events in human cancers that correlate with poor prognosis. Anti-phosphotyrosine and anti-EGFr affinity chromatography, isotope-coded muLC-MS/MS, and immunoblot methods were combined to describe and measure signaling networks associated with EGF receptor activation and pharmacological inhibition. The squamous carcinoma cell line HN5, which overexpresses EGF receptor and displays sustained receptor kinase activation, was used as a model system, where pharmacological inhibition of EGF receptor kinase by erlotinib markedly reduced auto and substrate phosphorylation, Src family phosphorylation at EGFR Y845, while increasing total EGF receptor protein. Diverse sets of known and poorly described functional protein classes were unequivocally identified by affinity selection, comprising either proteins tyrosine phosphorylated or complexed therewith, predominantly through EGF receptor and Src family kinases, principally 1) immediate EGF receptor signaling complexes (18%); 2) complexes involved in adhesion and cell-cell contacts (34%); and 3) receptor internalization and degradation signals. Novel and known phosphorylation sites could be located despite the complexity of the peptide mixtures. In addition to interactions with multiple signaling adaptors Grb2, SHC, SCK, and NSP2, EGF receptors in HN5 cells were shown to form direct or indirect physical interactions with additional kinases including ACK1, focal adhesion kinase (FAK), Pyk2, Yes, EphA2, and EphB4. Pharmacological inhibition of EGF receptor kinase activity by erlotinib resulted in reduced phosphorylation of downstream signaling, for example through Cbl/Cbl-B, phospholipase Cgamma (PLCgamma), Erk1/2, PI-3 kinase, and STAT3/5. Focal adhesion proteins, FAK, Pyk2, paxillin, ARF/GIT1, and plakophillin were down-regulated by transient EGF stimulation suggesting a complex balance between growth factor induced kinase and phosphatase activities in the control of cell adhesion complexes. The functional interactions between IGF-1 receptor, lysophosphatidic acid (LPA) signaling, and EGF receptor were observed, both direct and/or indirectly on phospho-Akt, phospho-Erk1/2, and phospho-ribosomal S6.
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Singh AJ, Meyer RD, Band H, Rahimi N. The carboxyl terminus of VEGFR-2 is required for PKC-mediated down-regulation. Mol Biol Cell 2005; 16:2106-18. [PMID: 15673613 PMCID: PMC1073687 DOI: 10.1091/mbc.e04-08-0749] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Vascular endothelial growth factor receptor-2 (VEGFR-2/Flk-1) is a receptor tyrosine kinase (RTK) whose activation regulates angiogenesis. The regulatory mechanisms that attenuate VEGFR-2 signal relay are largely unknown. Our study shows that VEGFR-2 promotes phosphorylation of c-Cbl, but activation, ubiquitylation, and down-regulation of VEGFR-2 are not influenced by c-Cbl activity. A structure-function analysis of VEGFR-2 and pharmacological approach revealed that down-regulation of VEGFR-2 is mediated by a distinct mechanism involving PKC. A tyrosine mutant VEGFR-2, defective in PLC-gamma1 activation underwent down-regulation efficiently in response to ligand stimulation, suggesting that activation of classical PKCs are not involved in VEGFR-2 down-regulation. Further studies showed that the ectodomain of VEGFR-2 is dispensable for PKC-dependent down-regulation. Progressive deletion of the carboxyl-terminal domain showed that at least 39 amino acids within the carboxyl-terminal domain, immediately C-terminal to the kinase domain, is required for efficient PKC-mediated down-regulation of VEGFR-2. Mutation of serine sites at 1188 and 1191, within this 39 amino acid region, compromised the ability of VEGFR-2 to undergo efficient ligand-dependent down-regulation. Altogether the results show that the regulatory mechanisms involved in the attenuation of VEGFR-2 activation is mediated by nonclassical PKCs and the presence of serine sites in the carboxyl terminal of VEGFR-2.
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Affiliation(s)
- Amrik J Singh
- Department of Ophthalmology, Boston University School of Medicine, MA 02118, USA
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Purdom S, Chen QM. Epidermal Growth Factor Receptor-Dependent and -Independent Pathways in Hydrogen Peroxide-Induced Mitogen-Activated Protein Kinase Activation in Cardiomyocytes and Heart Fibroblasts. J Pharmacol Exp Ther 2004; 312:1179-86. [PMID: 15574683 DOI: 10.1124/jpet.104.077057] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Mild doses of oxidative stress in the heart correlate with the induction of apoptosis or hypertrophy in cardiomyocytes (CMCs) and fibrosis or proliferation of fibroblasts. Three branches of mitogen-activated protein kinases (MAPKs), i.e., c-Jun N-terminal kinases (JNKs), extracellular signal-related kinases 1 and 2 (ERK1/2), and p38, are activated by oxidants in a variety of cell types, including CMCs. However, the initiation process of these signaling pathways remains unsolved. We explored the role of the epidermal growth factor (EGF) receptor in H(2)O(2)-induced MAPK activation using two different cell types from the same organ: CMCs and heart fibroblasts (HFs). Pretreatment of each cell type with EGF revealed differences in how CMCs and HFs responded to subsequent treatment with H(2)O(2): in CMCs, the second treatment resulted in little further activation of JNKs and ERK1/2, whereas HFs retained the full response of JNKs and ERK1/2 activation by H(2)O(2) regardless of EGF pretreatment. AG-1478 [4-(3'-chloroanilino)-6,7-dimethoxy-quinazoline], a pharmacologic inhibitor of the EGF receptor tyrosine kinase, inhibited JNK and ERK1/2 activations but not p38 in both cell types. The data using the Src inhibitor PP2 [4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine] resemble those found when using AG-1478 in either cell type. Pharmacologic inhibitors of matrix metalloproteinases (MMPs) further illustrated the difference between the two cell types. In HFs, MMP inhibitors GM6001 [N-[(2R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl]-l-tryptophan methylamide] and BB2516 [[2S-[N4(R(*)),2R(*),3S(*)]]-N4-[2,2-dimethyl-1-[(methylamino)carbonyl]propyl]-N1,2-dihydroxy-3-(2-methylpropyl)butanediamide, marimastat] inhibited JNKs and ERK1/2 activation without affecting p38 activation by H(2)O(2) inhibitors. In contrast, these MMP failed to significantly inhibit the activation of JNKs, ERKs, or p38 in CMCs. These data suggest the complexity of the cell type-dependent signaling web initiated by oxidants in the heart.
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Affiliation(s)
- Sally Purdom
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Ave., Tucson, AZ 85724, USA
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Dong J, Ramachandiran S, Tikoo K, Jia Z, Lau SS, Monks TJ. EGFR-independent activation of p38 MAPK and EGFR-dependent activation of ERK1/2 are required for ROS-induced renal cell death. Am J Physiol Renal Physiol 2004; 287:F1049-58. [PMID: 15226155 DOI: 10.1152/ajprenal.00132.2004] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
2,3,5-Tris-(glutathion-S-yl)hydroquinone (TGHQ), a reactive metabolite of the nephrotoxicant hydroquinone, induces the ROS-dependent activation of MAPKs, followed by histone H3 phosphorylation and oncotic cell death in renal proximal tubule epithelial cells (LLC-PK(1)). Cell death and histone H3 phosphorylation are attenuated by pharmacological inhibition of p38 MAPK or ERK1/2 pathways. Because TGHQ, but not epidermal growth factor (EGF), induces histone H3 phosphorylation and cell death in LLC-PK(1) cells, we hypothesized that there are differences in the mechanisms by which TGHQ and EGF induce activation of the EGF receptor (EGFR). We therefore compared the relative ability of TGHQ, H(2)O(2), and EGF to activate EGFR and MAPKs and found that p38 MAPK activation is EGFR independent, whereas ERK1/2 activation occurs mainly through EGFR activation. TGHQ, H(2)O(2), and EGF induce different EGFR tyrosine phosphorylation profiles that likely influence the subsequent differential kinetics of MAPK activation. We next transfected LLC-PK(1) cells with a dominant negative p38 MAPK-expressing plasmid (pcDNA3-DNp38). TGHQ failed to induce phosphorylation of p38 MAPK and its substrate, MK-2, in pcDNA3-DNp38-transfected cells, indicating loss of function of p38 MAPK. In untransfected, pcDNA3 or pcDNA3-p38 (native)-transfected LLC-PK(1) cells, Hsp27 was intensively phosphorylated after TGHQ treatment, whereas in pcDNA3-DNp38-transfected cells, TGHQ failed to induce Hsp27 phosphorylation. Thus EGFR-independent p38 MAPK and EGFR-dependent ERK1/2 activation by TGHQ lead to the activation of two downstream signaling factors, i.e., histone H3 and Hsp27 phosphorylation, which have in common the potential ability to remodel chromatin.
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Affiliation(s)
- Jing Dong
- Dept. of Pharmacology and Toxicology, College of Pharmacy, University of Arizona Health Sciences Center, Tucson, AZ 85721, USA
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Stoorvogel W, Kerstens S, Fritzsche I, den Hartigh JC, Oud R, van der Heyden MAG, Voortman J, van Bergen en Henegouwen PMP. Sorting of ligand-activated epidermal growth factor receptor to lysosomes requires its actin-binding domain. J Biol Chem 2003; 279:11562-9. [PMID: 14702346 DOI: 10.1074/jbc.m308449200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ligand-induced down-regulation of the epidermal growth factor receptor (EGFR) comprises activation of two sequential transport steps. The first involves endocytic uptake by clathrin-coated vesicles, the second transfer of endocytosed EGFR from endosomes to lysosomes. Here we demonstrate that the second transport step requires a domain of the EGFR that encompasses residues 985-996 and was previously found to interact with actin. Deletion of domain 989-994 (Delta989-994 EGFR) did not interfere with EGFR uptake but completely abrogated its degradation. In contrast, both uptake and degradation were affected for K721A EGFR, a kinase-deficient EGFR mutant. To measure intracellular EGFR sorting, we developed a novel cell fractionation assay toward which cells were co-transfected for chicken hepatic lectin, a receptor for agialoglycoproteins. These cells were incubated with agialofetuin-coupled colloidal gold, which was targeted to lysosomes after receptor-mediated endocytosis. Compartments within the lysosomal pathway gained buoyant density because of the presence of colloidal gold and could be isolated from cell homogenates by ultracentrifugation through a high-density sucrose cushion. In contrast to endocytosed wild type EGFR, both Delta989-994 EGFR and K721A EGFR were largely not retrieved in gold-containing endocytic compartments. These results are supported with morphological data. We conclude that sorting of endocytosed EGFR into the degradation pathway requires both its kinase activity and actin-binding domain.
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Affiliation(s)
- Willem Stoorvogel
- Department of Cell Biology at the University Medical Center, Utrecht University, The Netherlands.
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39
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Serresi M, Piccinini G, Pierpaoli E, Fazioli F. A ligand-inducible anaplastic lymphoma kinase chimera is endocytosis impaired. Oncogene 2003; 23:1098-108. [PMID: 14691459 DOI: 10.1038/sj.onc.1207227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ligand-induced membrane trafficking of the anaplastic lymphoma kinase (ALK) was studied using a chimeric receptor in which the extracellular and transmembrane domain of ALK was substituted for the corresponding regions of epidermal growth factor receptor (EGFR). Wild-type EGFR, EGFR/ALK and an EGFR/ALK kinase negative mutant were independently expressed in mouse NR6 fibroblasts. The capacity of EGFR/ALK to mediate [125I]-EGF internalization, receptor degradation and downregulation, which has never been previously described, was assayed. The rate of [125I]-EGF-induced internalization mediated by the cytoplasmic domain of ALK was reduced several fold compared with the wild-type EGFR. The low rate of EGF internalization promoted by EGFR/ALK correlated with an impaired degradation and downregulation of the receptor and indicate that ALK is not subject to traditional mechanisms used to regulate receptor tyrosine kinase function. Accordingly, ALK-activated intracellular domain does not associate in vivo with c-cbl and does not undergo ligand-mediated ubiquitination. The current study provides new insight into the function and regulation of ALK suggesting that the relative long membrane residence of activated ALK might confers a more potent and prolonged signaling activity. Indeed NR6-EGFR/ALK cells exhibited a approximately 3-fold increase in a maximal mitogenic response than NR6-EGFR.
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Affiliation(s)
- Michela Serresi
- Laboratory of Cellular and Molecular Biology, Institute of Clinical Medicine, University of Ancona, Via Tronto 10/A, 60020 Ancona, Italy
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40
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Oksvold MP, Thien CBF, Widerberg J, Chantry A, Huitfeldt HS, Langdon WY. Serine mutations that abrogate ligand-induced ubiquitination and internalization of the EGF receptor do not affect c-Cbl association with the receptor. Oncogene 2003; 22:8509-18. [PMID: 14627991 DOI: 10.1038/sj.onc.1207117] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the present study, we examined EGF-induced internalization, degradation and trafficking of the epidermal growth factor receptor (EGFR) mutated at serines 1046, 1047, 1057 and 1142 located in its cytoplasmic carboxy-terminal region. We found the serine-mutated EGFR to be inhibited in EGF-induced internalization and degradation in NIH3T3 cells. We therefore tested the hypothesis that these mutations affect ligand-induced c-Cbl association with the receptor, leading to inhibited receptor ubiquitination. EGF was unable to induce ubiquitination of the serine-mutated EGFR, yet EGF-induced phosphorylation of the c-Cbl-binding site at tyrosine 1045, and c-Cbl-EGFR association, was unaffected. To compare the relevance of these serine residues with tyrosine 1045 in their regulation of c-Cbl binding and receptor ubiquitination, we analysed an EGFR mutated at tyrosine 1045 (Y1045F). EGF-induced c-Cbl-EGFR binding was partially inhibited, and receptor ubiquitination was abrogated in cells expressing Y1045F-EGFR. In contrast, ligand-induced internalization and degradation of the Y1045F mutant was similar to that of wild-type EGFR. Together, our data indicate that the serine residues and tyrosine 1045 are essential for EGF-induced receptor ubiquitination, but only the serine residues are critical for EGFR internalization and degradation.
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Affiliation(s)
- Morten P Oksvold
- Department of Pathology, University of Western Australia, Queen Elizabeth II Medical Center, Nedlands, Western Australia 6009, Australia.
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41
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Abstract
A variety of receptors have been analyzed in sufficient detail to identify sorting motifs. Initial studies focused on the identification of sequences in the cytoplasmic tails of the LDL and transferrin receptors that mediated their internalization. These motifs have since been found in the cytoplasmic domains of a wide variety of receptors and provide for numerous sorting functions. This review will outline the early studies on LDL and transferrin receptors and will then focus on two classes of signaling receptors, receptor tyrosine kinases (EGF and the insulin receptors) and heterotrimeric G-protein coupled receptors (beta2-adrenergic receptors). The identification of sorting motifs and proteins that bind these motifs will be discussed. Importantly, the studies identify a variety of potential targets for modulating the sorting and hence activity of these medically important receptors.
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MESH Headings
- Amino Acid Motifs
- Animals
- Endocytosis/physiology
- ErbB Receptors/metabolism
- ErbB Receptors/physiology
- Humans
- Protein Sorting Signals/physiology
- Receptor, Insulin/metabolism
- Receptor, Insulin/physiology
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-2/physiology
- Receptors, Cell Surface/metabolism
- Receptors, Cell Surface/physiology
- Receptors, LDL/metabolism
- Receptors, LDL/physiology
- Receptors, Transferrin/metabolism
- Receptors, Transferrin/physiology
- Signal Transduction
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Affiliation(s)
- Richard C Kurten
- Department Physiology and Biophysics, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72005, USA.
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42
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Agazie YM, Hayman MJ. Molecular mechanism for a role of SHP2 in epidermal growth factor receptor signaling. Mol Cell Biol 2003; 23:7875-86. [PMID: 14560030 PMCID: PMC207628 DOI: 10.1128/mcb.23.21.7875-7886.2003] [Citation(s) in RCA: 226] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2003] [Revised: 06/16/2003] [Accepted: 07/29/2003] [Indexed: 11/20/2022] Open
Abstract
The Src homology 2-containing phosphotyrosine phosphatase (SHP2) is primarily a positive effector of receptor tyrosine kinase signaling. However, the molecular mechanism by which SHP2 effects its biological function is unknown. In this report, we provide evidence that defines the molecular mechanism and site of action of SHP2 in the epidermal growth factor-induced mitogenic pathway. We demonstrate that SHP2 acts upstream of Ras and functions by increasing the half-life of activated Ras (GTP-Ras) in the cell by interfering with the process of Ras inactivation catalyzed by Ras GTPase-activating protein (RasGAP). It does so by inhibition of tyrosine phosphorylation-dependent translocation of RasGAP to the plasma membrane, to its substrate (GTP-Ras) microdomain. Inhibition is achieved through the dephosphorylation of RasGAP binding sites at the level of the plasma membrane. We have identified Tyr992 of the epidermal growth factor receptor (EGFR) to be one such site, since its mutation to Phe renders the EGFR refractory to the effect of dominant-negative SHP2. To our knowledge, this is the first report to outline the site and molecular mechanism of action of SHP2 in EGFR signaling, which may also serve as a model to describe its role in other receptor tyrosine kinase signaling pathways.
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Affiliation(s)
- Yehenew M Agazie
- Department of Molecular Genetics and Microbiology, Health Sciences Center, Stony Brook University, Stony Brook, New York 11794-5222, USA
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43
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Draper BK, Komurasaki T, Davidson MK, Nanney LB. Epiregulin is more potent than EGF or TGFalpha in promoting in vitro wound closure due to enhanced ERK/MAPK activation. J Cell Biochem 2003; 89:1126-37. [PMID: 12898511 DOI: 10.1002/jcb.10584] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Epiregulin (EPR) is a broad specificity EGF family member that activates ErbB1 and ErbB4 homodimers and all possible heterodimeric ErbB complexes. We have previously shown that topical EPR enhances the repair of murine excisional wounds. The purpose of this study was to determine whether EPR was more effective than EGF or TGFalpha in promoting in vitro wound closure and to compare the EPR induced signal transduction pathways with those activated by EGF and TGFalpha. Normal human epidermal keratinocytes or A431 cells were scratch wounded and treated for 24 h with varying doses of EPR, EGF or TGFalpha. Five-fold lower doses of EPR were significantly better than EGF or TGFalpha in stimulating in vitro wound closure. Mitomycin-c reduced EPR induced wound closure by 59%, versus a 9% and 25% decrease in EGF and TGFalpha induced closure. The ERK/MAPK inhibitor PD-98059 decreased EPR induced wound closure by 88%. By contrast, the PLC inhibitor U-73122, only reduced the EPR induced response by 21%. Immunoblot analysis revealed that 2 nM EPR stimulated a six-fold increase in p-ERK1/2, whereas 10 nM EGF or TGFalpha stimulated only a 3- and 2.5-fold increase in p-ERK1/2. When compared with EGF or TGFalpha, EPR is a more potent and more effective inducer of in vitro wound closure due to its ability to promote significantly greater ERK/MAPK activation.
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Affiliation(s)
- Bradley K Draper
- Department of Medicine (Dermatology), Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
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44
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Jiang X, Sorkin A. Epidermal growth factor receptor internalization through clathrin-coated pits requires Cbl RING finger and proline-rich domains but not receptor polyubiquitylation. Traffic 2003; 4:529-43. [PMID: 12839496 DOI: 10.1034/j.1600-0854.2003.t01-1-00109.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cbl proteins have been implicated in the regulation of endocytic trafficking of epidermal growth factor receptor. However, the precise role of Cbl in epidermal growth factor receptor endocytosis is not defined. To directly visualize Cbl in cells and perform structure-function analysis of Cbl's role in epidermal growth factor receptor internalization, a yellow fluorescent protein-fusion of c-Cbl was constructed. Upon epidermal growth factor receptor activation, Cbl-yellow fluorescent protein moved with epidermal growth factor receptor to clathrin-coated pits and endosomes. Localization of Cbl-yellow fluorescent protein to these endocytic organelles was dependent on a proline-rich domain of c-Cbl that interacts with Grb2 as shown by fluorescence resonance energy transfer microscopy. In contrast, direct binding of Cbl to phosphotyrosine 1045 of the epidermal growth factor receptor was required for epidermal growth factor receptor polyubiquitination, but was not essential for Cbl-yellow fluorescent protein localization in epidermal growth factor receptor-containing compartments. These data suggest that the binding of Cbl to epidermal growth factor receptor through Grb2 is necessary and sufficient for Cbl function during clathrin-mediated endocytosis. Overexpression of c-Cbl mutants that are capable of Grb2 binding but defective in linker/RING finger domain function severely inhibited epidermal growth factor receptor internalization. The same dominant-negative mutants of Cbl did not block epidermal growth factor receptor recruitment into coated pits but retained receptors in coated pits, thus preventing receptor endocytosis and transport to endosomes. These data suggest that the linker and RING finger domain of Cbl may function during late steps of coated vesicle formation. We propose that the RING domain of Cbl facilitates endocytosis either by epidermal growth factor receptor monoubiquitylation or by ubiquitylation of proteins associated with the receptor.
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Affiliation(s)
- Xuejun Jiang
- Department of Pharmacology, University of Colorado Health Sciences Center, Denver, Colorado 80111, USA
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45
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Draper BK, Komurasaki T, Davidson MK, Nanney LB. Topical epiregulin enhances repair of murine excisional wounds. Wound Repair Regen 2003; 11:188-97. [PMID: 12753600 DOI: 10.1046/j.1524-475x.2003.11307.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Epiregulin is a broad specificity epidermal growth factor family member that activates ErbB1 and ErbB4 homodimers and all possible heterodimeric ErbB complexes. Our objective was to determine whether topical epiregulin enhanced repair of murine excisional wounds. Wounds were treated on days 0-4 with either topical epiregulin (1 micro g/ml), epidermal growth factor (10 micro g/ml), or vehicle. At day 5 postinjury, wounds receiving epiregulin were significantly smaller than those treated with epidermal growth factor or vehicle. Treatment with epiregulin promoted greater epidermal proliferation and thickening than epidermal growth factor or vehicle due to an expansion of the proliferative compartment of keratinocytes. Dermal thickness was also increased in epiregulin-treated wounds as compared to those treated with epidermal growth factor or vehicle. In day 5 wounds, matrix metalloproteinase-3 (stromelysin-1) mRNA levels were significantly lower in epiregulin- or epidermal growth factor-treated wounds than in vehicle-treated controls, suggesting that growth factor-treated wounds were more mature and required less ongoing proteolytic activity than their same-day vehicle-treated counterparts. This is the first report that topical epiregulin accelerates repair of full-thickness murine excisional wounds as compared to vehicle or epidermal growth factor. Furthermore, epiregulin is more potent and more effective than epidermal growth factor in promoting proliferation and maturation of the epidermis as well as enhancement of the neodermis.
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Affiliation(s)
- Bradley K Draper
- Department of Medicine (Dermatology), Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
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46
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Jiang X, Huang F, Marusyk A, Sorkin A. Grb2 regulates internalization of EGF receptors through clathrin-coated pits. Mol Biol Cell 2003; 14:858-70. [PMID: 12631709 PMCID: PMC151565 DOI: 10.1091/mbc.e02-08-0532] [Citation(s) in RCA: 243] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The molecular mechanisms of clathrin-dependent internalization of epidermal growth factor receptor (EGFR) are not well understood and, in particular, the sequence motifs that mediate EGFR interactions with coated pits have not been mapped. We generated a panel of EGFR mutants and stably expressed these mutants in porcine aortic endothelial (PAE) cells. Interestingly, mutations of tyrosine phosphorylation sites 1068 and 1086 that interact with growth-factor-receptor-binding protein Grb2 completely abolished receptor internalization in PAE cells. Quantitative analysis of colocalization of EGF-rhodamine conjugate and coated pits labeled with yellow-fluorescent-protein-tagged beta2 subunit of clathrin adaptor complex AP-2 revealed that EGFR mutants lacking Grb2 binding sites do not efficiently enter coated pits. The depletion of Grb2 from PAE as well as HeLa cells expressing endogenous EGFRs by RNA interference substantially reduced the rate of EGFR internalization through clathrin-dependent pathway, thus providing the direct evidence for the important role of Grb2 in this process. Overexpression of Grb2 mutants, in which the SH3 domains were either deleted or inactivated by point mutations, significantly inhibited EGFR internalization in both PAE and HeLa cells. These findings indicate that Grb2, in addition to its key function in signaling through Ras, has a major regulatory role at the initial steps of EGFR internalization through clathrin-coated pits. Furthermore, the EGFR mutant lacking Grb2 binding sites did not efficiently recruit c-Cbl and was not polyubiquitinated. The data are consistent with the model whereby Grb2 participates in EGFR internalization through the recruitment of Cbl to the receptor, thus allowing proper ubiquitylation of EGFR and/or associated proteins at the plasma membrane.
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Affiliation(s)
- Xuejun Jiang
- Department of Pharmacology, University of Colorado Health Sciences Center, Denver 80111, USA
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47
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Bayatti N, Engele J. Cyclic AMP differentially regulates the expression of fibroblast growth factor and epidermal growth factor receptors in cultured cortical astroglia. Neuroscience 2002; 114:81-9. [PMID: 12207956 DOI: 10.1016/s0306-4522(02)00222-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Fibroblast growth factor (FGF)-2 and transforming growth factor alpha (TGFalpha) promote astroglial proliferation during brain development and reactive processes. The mitogenic potential of both growth factors is attenuated by increasing intracellular cAMP levels, an effect currently assumed to depend on the inhibition of the mitogen-activated protein kinase cascade. In the present study, we sought to determine whether cAMP interferes with the mitogenic potential of FGF-2 and TGFalpha on astroglia by affecting the expression of respective growth factor receptors. Treatment of highly enriched cultures of cortical astrocytes with dibutyryl cAMP accelerated the TGFalpha-induced internalization and subsequent functional inactivation of epidermal growth factor (EGF) receptor by transiently inhibiting EGF receptor mRNA synthesis. In apparent contrast, both short- and long-term activation of cAMP-dependent signaling pathways robustly promoted the expression of FGF receptors 1 and 2, whereas expression levels of FGF receptor 3 remained unaffected. Moreover, elevation of intracellular cAMP levels did not prevent translocation of FGF receptor 1 to the cell nucleus, a mechanism thought to be essential for FGF-2-induced cell proliferation. We propose that cAMP controls the mitogenic effects of TGFalpha and FGF-2 on astroglial cells by distinctly different mechanisms. Whereas cAMP seems to interfere with the mitogenic effects of TGFalpha on astroglial cells by affecting both the expression level and signaling of the EGF receptor, the modulatory effects of cAMP on FGF-2-induced astroglial proliferation seem to solely result from an inhibition of FGF receptor-activated signaling pathways.
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Affiliation(s)
- N Bayatti
- Anatomie und Zellbiologie, Universität Ulm, 89069 Ulm, Germany
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48
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Sorkina T, Huang F, Beguinot L, Sorkin A. Effect of tyrosine kinase inhibitors on clathrin-coated pit recruitment and internalization of epidermal growth factor receptor. J Biol Chem 2002; 277:27433-41. [PMID: 12021271 DOI: 10.1074/jbc.m201595200] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Several inhibitors of epidermal growth factor receptor (EGFR) kinase and Src family kinases (SFK) were employed to study the role of these kinases in EGFR internalization through clathrin-coated pits. The EGFR kinase-specific compound PD158780 substantially diminished EGFR internalization. PP2, an inhibitor of SFK, had a moderate effect on EGFR internalization in several types of cells, including cells lacking SFK, indicating that the inhibition of endocytosis by PP2 is mediated by kinases other than SFK. In contrast, SU6656, a more specific inhibitor of SFK, did not affect EGFR internalization. To examine what stage of internalization requires receptor kinase activity, we established a quantitative assay based on three-dimensional fluorescence microscopy that measures co-localization of an EGF-rhodamine conjugate and a fluorescently tagged clathrin adaptor protein complex, AP-2. Interestingly, recruitment of EGFR into coated pits did not require physiological temperature because the maximal accumulation of EGFR in coated pits was observed at 4 degrees C. Pretreatment of the cells with PD158780 prevented EGFR recruitment into coated pits, whereas the inhibitor did not block the internalization of receptors that had first been allowed to enter the coated pits at 4 degrees C. These data demonstrate that the activation of receptor kinase is essential for the initial, coated pit recruitment step of endocytosis.
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Affiliation(s)
- Tatiana Sorkina
- Department of Pharmacology, University of Colorado Health Sciences Center, 4200 E Ninth Avenue, Denver, CO 80111, USA
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49
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Hackel PO, Gishizky M, Ullrich A. Mig-6 is a negative regulator of the epidermal growth factor receptor signal. Biol Chem 2001; 382:1649-62. [PMID: 11843178 DOI: 10.1515/bc.2001.200] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In contrast to signal generation and transmission, the mechanisms and molecules that negatively regulate receptor tyrosine kinase (RTK) signaling are poorly understood. Here we characterize Mig-6 as a novel negative feedback regulator of the epidermal growth factor receptor (EGFR) and potential tumor suppressor. Mig-6 was identified in a yeast two-hybrid screen with the kinase active domain of the EGFR as bait. Upon EGF stimulation Mig-6 binds to the EGFR involving a highly acidic region between amino acids 985-995. This interaction is kinase activity-dependent, but independent of tyrosine 992. Mig-6 overexpression results in reduced activation of the mitogenactivated protein kinase ERK2 in response to EGF, but not FGF or PDGF, stimulation and in enhanced receptor internalization without affecting the rate of degradation. The induction of Mig-6 mRNA expression in response to EGF, but not FGF, indicates the existence of a negative regulatory feedback loop. Consistent with these findings, a possible role as tumor suppressor is indicated by Mig-6-mediated inhibition of EGFR overexpression-induced transformation of Rati cells.
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Affiliation(s)
- P O Hackel
- Department of Molecular Biology, Max-Planck-Institute of Biochemistry, Martinsried, Germany
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50
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Kim I, Mogford JE, Chao JD, Mustoe TA. Wound epithelialization deficits in the transforming growth factor-alpha knockout mouse. Wound Repair Regen 2001; 9:386-90. [PMID: 11896982 DOI: 10.1046/j.1524-475x.2001.00386.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In vitro, transforming growth factor-alpha is an important factor controlling epithelial cell proliferation and migration. However, the transforming growth factor-alpha knockout mouse has shown no wound epithelialization defect in tail amputation and full-thickness back wounds. To resolve this disparity, we combined a full-thickness head wound and a partial-thickness ear wound on the transforming growth factor-alpha knockout mouse for analysis of wound epithelialization with or without granulation tissue formation. Three-millimeter ear wounds were made on the transforming growth factor-alpha knockout and heterozygous control mice. Full-thickness head wounds were made using a 6-mm trephine on the crown of the skull. In the ear model, transforming growth factor-alpha knockout mice had significantly larger epithelial gaps versus control at post-operative day 3 and 5. Epithelial thickness at the wound edge of transforming growth factor-alpha deficient mice was also depressed at post-operative day 3 and post-operative day 5 compared to control mice. On post-operative day 8, most wounds of both groups were epithelialized. In contrast, no difference in epithelial gap or new granulation tissue was found in the head model. The data support the concept that transforming growth factor-alpha plays a significant early role in wound epithelialization in vivo but its deficit is compensated if accompanied by granulation tissue formation. The data further show the importance of appropriate wound models to address the role of vulnerary factors.
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Affiliation(s)
- I Kim
- Wound Healing Research Laboratory, Division of Plastic & Reconstructive Surgery, Northwestern University Medical School, Chicago, Illinois 60611, USA
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