1
|
Manso JA, Carabias A, Sárkány Z, de Pereda JM, Pereira PJB, Macedo-Ribeiro S. Pathogen-specific structural features of Candida albicans Ras1 activation complex: uncovering new antifungal drug targets. mBio 2023; 14:e0063823. [PMID: 37526476 PMCID: PMC10470544 DOI: 10.1128/mbio.00638-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/16/2023] [Indexed: 08/02/2023] Open
Abstract
An important feature associated with Candida albicans pathogenicity is its ability to switch between yeast and hyphal forms, a process in which CaRas1 plays a key role. CaRas1 is activated by the guanine nucleotide exchange factor (GEF) CaCdc25, triggering hyphal growth-related signaling pathways through its conserved GTP-binding (G)-domain. An important function in hyphal growth has also been proposed for the long hypervariable region downstream the G-domain, whose unusual content of polyglutamine stretches and Q/N repeats make CaRas1 unique within Ras proteins. Despite its biological importance, both the structure of CaRas1 and the molecular basis of its activation by CaCdc25 remain unexplored. Here, we show that CaRas1 has an elongated shape and limited conformational flexibility and that its hypervariable region contains helical structural elements, likely forming an intramolecular coiled-coil. Functional assays disclosed that CaRas1-activation by CaCdc25 is highly efficient, with activities up to 2,000-fold higher than reported for human GEFs. The crystal structure of the CaCdc25 catalytic region revealed an active conformation for the α-helical hairpin, critical for CaRas1-activation, unveiling a specific region exclusive to CTG-clade species. Structural studies on CaRas1/CaCdc25 complexes also revealed an interaction surface clearly distinct from that of homologous human complexes. Furthermore, we identified an inhibitory synthetic peptide, prompting the proposal of a key regulatory mechanism for CaCdc25. To our knowledge, this is the first report of specific inhibition of the CaRas1-activation via targeting its GEF. This, together with their unique pathogen-structural features, disclose a set of novel strategies to specifically block this important virulence-related mechanism. IMPORTANCE Candida albicans is the main causative agent of candidiasis, the commonest fungal infection in humans. The eukaryotic nature of C. albicans and the rapid emergence of antifungal resistance raise the challenge of identifying novel drug targets to battle this prevalent and life-threatening disease. CaRas1 and CaCdc25 are key players in the activation of signaling pathways triggering multiple virulence traits, including the yeast-to-hypha interconversion. The structural similarity of the conserved G-domain of CaRas1 to those of human homologs and the lack of structural information on CaCdc25 has impeded progress in targeting these proteins. The unique structural and functional features for CaRas1 and CaCdc25 presented here, together with the identification of a synthetic peptide capable of specifically inhibiting the GEF activity of CaCdc25, open new possibilities to uncover new antifungal drug targets against C. albicans virulence.
Collapse
Affiliation(s)
- José A. Manso
- IBMC–Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Arturo Carabias
- Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas-University of Salamanca, Salamanca, Spain
| | - Zsuzsa Sárkány
- IBMC–Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - José M. de Pereda
- Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas-University of Salamanca, Salamanca, Spain
| | - Pedro José Barbosa Pereira
- IBMC–Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Sandra Macedo-Ribeiro
- IBMC–Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| |
Collapse
|
2
|
Ahmed MB, Alghamdi AAA, Islam SU, Lee JS, Lee YS. cAMP Signaling in Cancer: A PKA-CREB and EPAC-Centric Approach. Cells 2022; 11:cells11132020. [PMID: 35805104 PMCID: PMC9266045 DOI: 10.3390/cells11132020] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/17/2022] [Accepted: 06/23/2022] [Indexed: 02/01/2023] Open
Abstract
Cancer is one of the most common causes of death globally. Despite extensive research and considerable advances in cancer therapy, the fundamentals of the disease remain unclear. Understanding the key signaling mechanisms that cause cancer cell malignancy may help to uncover new pharmaco-targets. Cyclic adenosine monophosphate (cAMP) regulates various biological functions, including those in malignant cells. Understanding intracellular second messenger pathways is crucial for identifying downstream proteins involved in cancer growth and development. cAMP regulates cell signaling and a variety of physiological and pathological activities. There may be an impact on gene transcription from protein kinase A (PKA) as well as its downstream effectors, such as cAMP response element-binding protein (CREB). The position of CREB downstream of numerous growth signaling pathways implies its oncogenic potential in tumor cells. Tumor growth is associated with increased CREB expression and activation. PKA can be used as both an onco-drug target and a biomarker to find, identify, and stage tumors. Exploring cAMP effectors and their downstream pathways in cancer has become easier using exchange protein directly activated by cAMP (EPAC) modulators. This signaling system may inhibit or accelerate tumor growth depending on the tumor and its environment. As cAMP and its effectors are critical for cancer development, targeting them may be a useful cancer treatment strategy. Moreover, by reviewing the material from a distinct viewpoint, this review aims to give a knowledge of the impact of the cAMP signaling pathway and the related effectors on cancer incidence and development. These innovative insights seek to encourage the development of novel treatment techniques and new approaches.
Collapse
Affiliation(s)
- Muhammad Bilal Ahmed
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu 41566, Korea; (M.B.A.); (J.-S.L.)
| | | | - Salman Ul Islam
- Department of Pharmacy, Cecos University, Peshawar, Street 1, Sector F 5 Phase 6 Hayatabad, Peshawar 25000, Pakistan;
| | - Joon-Seok Lee
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu 41566, Korea; (M.B.A.); (J.-S.L.)
| | - Young-Sup Lee
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu 41566, Korea; (M.B.A.); (J.-S.L.)
- Correspondence: ; Tel.: +82-53-950-6353; Fax: +82-53-943-2762
| |
Collapse
|
3
|
Han CW, Jeong MS, Jang SB. Understand KRAS and the Quest for Anti-Cancer Drugs. Cells 2021; 10:cells10040842. [PMID: 33917906 PMCID: PMC8068306 DOI: 10.3390/cells10040842] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/06/2021] [Accepted: 04/06/2021] [Indexed: 12/30/2022] Open
Abstract
The KRAS oncogene is mutated in approximately ~30% of human cancers, and the targeting of KRAS has long been highlighted in many studies. Nevertheless, attempts to target KRAS directly have been ineffective. This review provides an overview of the structure of KRAS and its characteristic signaling pathways. Additionally, we examine the problems associated with currently available KRAS inhibitors and discuss promising avenues for drug development.
Collapse
Affiliation(s)
- Chang Woo Han
- Institute of Systems Biology, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 46241, Korea;
| | - Mi Suk Jeong
- Institute for Plastic Information and Energy Materials and Sustainable Utilization of Photovoltaic Energy Research Center, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 46241, Korea
- Correspondence: (M.S.J.); (S.B.J.); Tel.: +82-51-510-2523 (M.S.J. & S.B.J.)
| | - Se Bok Jang
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 46241, Korea
- Correspondence: (M.S.J.); (S.B.J.); Tel.: +82-51-510-2523 (M.S.J. & S.B.J.)
| |
Collapse
|
4
|
Wehbe N, Slika H, Mesmar J, Nasser SA, Pintus G, Baydoun S, Badran A, Kobeissy F, Eid AH, Baydoun E. The Role of Epac in Cancer Progression. Int J Mol Sci 2020; 21:ijms21186489. [PMID: 32899451 PMCID: PMC7555121 DOI: 10.3390/ijms21186489] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/14/2022] Open
Abstract
Cancer continues to be a prime contributor to global mortality. Despite tremendous research efforts and major advances in cancer therapy, much remains to be learned about the underlying molecular mechanisms of this debilitating disease. A better understanding of the key signaling events driving the malignant phenotype of cancer cells may help identify new pharmaco-targets. Cyclic adenosine 3',5'-monophosphate (cAMP) modulates a plethora of biological processes, including those that are characteristic of malignant cells. Over the years, most cAMP-mediated actions were attributed to the activity of its effector protein kinase A (PKA). However, studies have revealed an important role for the exchange protein activated by cAMP (Epac) as another effector mediating the actions of cAMP. In cancer, Epac appears to have a dual role in regulating cellular processes that are essential for carcinogenesis. In addition, the development of Epac modulators offered new routes to further explore the role of this cAMP effector and its downstream pathways in cancer. In this review, the potentials of Epac as an attractive target in the fight against cancer are depicted. Additionally, the role of Epac in cancer progression, namely its effect on cancer cell proliferation, migration/metastasis, and apoptosis, with the possible interaction of reactive oxygen species (ROS) in these phenomena, is discussed with emphasis on the underlying mechanisms and pathways.
Collapse
Affiliation(s)
- Nadine Wehbe
- Department of Biology, American University of Beirut, P.O. Box 11-0236 Beirut, Lebanon; (N.W.); (J.M.)
| | - Hasan Slika
- Department of Pharmacology and Therapeutics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Beirut, Lebanon;
| | - Joelle Mesmar
- Department of Biology, American University of Beirut, P.O. Box 11-0236 Beirut, Lebanon; (N.W.); (J.M.)
| | - Suzanne A. Nasser
- Department of Pharmacology, Beirut Arab University, P.O. Box 11-5020 Beirut, Lebanon;
| | - Gianfranco Pintus
- Department of Biomedical Sciences, University of Sharjah, P.O. Box 27272 Sharjah, UAE;
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43, 07100 Sassari, Italy
| | - Serine Baydoun
- Department of Radiology, American University of Beirut, P.O. Box 11-0236 Beirut, Lebanon;
| | - Adnan Badran
- Department of Basic Sciences, University of Petra, P.O. Box 961343, Amman 11196, Jordan;
| | - Firas Kobeissy
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon;
| | - Ali H. Eid
- Department of Pharmacology and Therapeutics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Beirut, Lebanon;
- Department of Pharmacology and Therapeutics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon
- Correspondence: (A.H.E.); (E.B.); Tel.: +961-1-350-000 (ext. 4891) (A.H.E. & E.B.)
| | - Elias Baydoun
- Department of Biology, American University of Beirut, P.O. Box 11-0236 Beirut, Lebanon; (N.W.); (J.M.)
- Correspondence: (A.H.E.); (E.B.); Tel.: +961-1-350-000 (ext. 4891) (A.H.E. & E.B.)
| |
Collapse
|
5
|
EPAC in Vascular Smooth Muscle Cells. Int J Mol Sci 2020; 21:ijms21145160. [PMID: 32708284 PMCID: PMC7404248 DOI: 10.3390/ijms21145160] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/09/2020] [Accepted: 07/19/2020] [Indexed: 02/07/2023] Open
Abstract
Vascular smooth muscle cells (VSMCs) are major components of blood vessels. They regulate physiological functions, such as vascular tone and blood flow. Under pathological conditions, VSMCs undergo a remodeling process known as phenotypic switching. During this process, VSMCs lose their contractility and acquire a synthetic phenotype, where they over-proliferate and migrate from the tunica media to the tunica interna, contributing to the occlusion of blood vessels. Since their discovery as effector proteins of cyclic adenosine 3′,5′-monophosphate (cAMP), exchange proteins activated by cAMP (EPACs) have been shown to play vital roles in a plethora of pathways in different cell systems. While extensive research to identify the role of EPAC in the vasculature has been conducted, much remains to be explored to resolve the reported discordance in EPAC’s effects. In this paper, we review the role of EPAC in VSMCs, namely its regulation of the vascular tone and phenotypic switching, with the likely involvement of reactive oxygen species (ROS) in the interplay between EPAC and its targets/effectors.
Collapse
|
6
|
Structural Insights into the Regulation Mechanism of Small GTPases by GEFs. Molecules 2019; 24:molecules24183308. [PMID: 31514408 PMCID: PMC6767298 DOI: 10.3390/molecules24183308] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/12/2022] Open
Abstract
Small GTPases are key regulators of cellular events, and their dysfunction causes many types of cancer. They serve as molecular switches by cycling between inactive guanosine diphosphate (GDP)-bound and active guanosine triphosphate (GTP)-bound states. GTPases are deactivated by GTPase-activating proteins (GAPs) and are activated by guanine-nucleotide exchange factors (GEFs). The intrinsic GTP hydrolysis activity of small GTPases is generally low and is accelerated by GAPs. GEFs promote GDP dissociation from small GTPases to allow for GTP binding, which results in a conformational change of two highly flexible segments, called switch I and switch II, that enables binding of the gamma phosphate and allows small GTPases to interact with downstream effectors. For several decades, crystal structures of many GEFs and GAPs have been reported and have shown tremendous structural diversity. In this review, we focus on the latest structural studies of GEFs. Detailed pictures of the variety of GEF mechanisms at atomic resolution can provide insights into new approaches for drug discovery.
Collapse
|
7
|
Eijkelenboom A, van Schaik FMA, van Es RM, Ten Broek RW, Rinne T, van der Vleuten C, Flucke U, Ligtenberg MJL, Rehmann H. Functional characterisation of a novel class of in-frame insertion variants of KRAS and HRAS. Sci Rep 2019; 9:8239. [PMID: 31160609 PMCID: PMC6547725 DOI: 10.1038/s41598-019-44584-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/17/2019] [Indexed: 12/15/2022] Open
Abstract
Mutations in the RAS genes are identified in a variety of clinical settings, ranging from somatic mutations in oncology to germline mutations in developmental disorders, also known as 'RASopathies', and vascular malformations/overgrowth syndromes. Generally single amino acid substitutions are identified, that result in an increase of the GTP bound fraction of the RAS proteins causing constitutive signalling. Here, a series of 7 in-frame insertions and duplications in HRAS (n = 5) and KRAS (n = 2) is presented, resulting in the insertion of 7-10 amino acids residues in the switch II region. These variants were identified in routine diagnostic screening of 299 samples for somatic mutations in vascular malformations/overgrowth syndromes (n = 6) and in germline analyses for RASopathies (n = 1). Biophysical characterization shows the inability of Guanine Nucleotide Exchange Factors to induce GTP loading and reduced intrinsic and GAP-stimulated GTP hydrolysis. As a consequence of these opposing effects, increased RAS signalling is detected in a cellular model system. Therefore these in-frame insertions represent a new class of weakly activating clinically relevant RAS variants.
Collapse
Affiliation(s)
- Astrid Eijkelenboom
- Department of Pathology, Radboud university medical center, Nijmegen, The Netherlands
| | - Frederik M A van Schaik
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, Utrecht, 3584 CX, The Netherlands
| | - Robert M van Es
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, Utrecht, 3584 CX, The Netherlands
| | - Roel W Ten Broek
- Department of Pathology, Radboud university medical center, Nijmegen, The Netherlands
| | - Tuula Rinne
- Department of Human Genetics, Radboud university medical center, Nijmegen, The Netherlands
| | - Carine van der Vleuten
- Department of Dermatology, Radboudumc Center of Expertise Hecovan, Radboud university medical center, Nijmegen, The Netherlands
| | - Uta Flucke
- Department of Pathology, Radboud university medical center, Nijmegen, The Netherlands
| | - Marjolijn J L Ligtenberg
- Department of Pathology, Radboud university medical center, Nijmegen, The Netherlands.,Department of Human Genetics, Radboud university medical center, Nijmegen, The Netherlands
| | - Holger Rehmann
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, Utrecht, 3584 CX, The Netherlands. .,Expertise Centre for Structural Biology, University Medical Center Utrecht, Utrecht University, Utrecht, 3584 CX, The Netherlands.
| |
Collapse
|
8
|
Bissen D, Foss F, Acker-Palmer A. AMPA receptors and their minions: auxiliary proteins in AMPA receptor trafficking. Cell Mol Life Sci 2019; 76:2133-2169. [PMID: 30937469 PMCID: PMC6502786 DOI: 10.1007/s00018-019-03068-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/12/2019] [Accepted: 03/07/2019] [Indexed: 12/12/2022]
Abstract
To correctly transfer information, neuronal networks need to continuously adjust their synaptic strength to extrinsic stimuli. This ability, termed synaptic plasticity, is at the heart of their function and is, thus, tightly regulated. In glutamatergic neurons, synaptic strength is controlled by the number and function of AMPA receptors at the postsynapse, which mediate most of the fast excitatory transmission in the central nervous system. Their trafficking to, at, and from the synapse, is, therefore, a key mechanism underlying synaptic plasticity. Intensive research over the last 20 years has revealed the increasing importance of interacting proteins, which accompany AMPA receptors throughout their lifetime and help to refine the temporal and spatial modulation of their trafficking and function. In this review, we discuss the current knowledge about the roles of key partners in regulating AMPA receptor trafficking and focus especially on the movement between the intracellular, extrasynaptic, and synaptic pools. We examine their involvement not only in basal synaptic function, but also in Hebbian and homeostatic plasticity. Included in our review are well-established AMPA receptor interactants such as GRIP1 and PICK1, the classical auxiliary subunits TARP and CNIH, and the newest additions to AMPA receptor native complexes.
Collapse
Affiliation(s)
- Diane Bissen
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
- Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438, Frankfurt am Main, Germany
| | - Franziska Foss
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
| | - Amparo Acker-Palmer
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
- Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438, Frankfurt am Main, Germany.
- Cardio-Pulmonary Institute (CPI), Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
| |
Collapse
|
9
|
Stefanini L, Bergmeier W. RAP GTPases and platelet integrin signaling. Platelets 2018; 30:41-47. [PMID: 29863951 PMCID: PMC6312509 DOI: 10.1080/09537104.2018.1476681] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 12/31/2022]
Abstract
Platelets are highly specialized cells that continuously patrol the vasculature to ensure its integrity (hemostasis). At sites of vascular injury, they are able to respond to trace amounts of agonists and to rapidly transition from an anti-adhesive/patrolling to an adhesive state (integrin inside-out activation) required for hemostatic plug formation. Pathological conditions that disturb the balance in the underlying signaling processes can lead to unwanted platelet activation (thrombosis) or to an increased bleeding risk. The small GTPases of the RAP subfamily, highly expressed in platelets, are critical regulators of cell adhesion, cytoskeleton remodeling, and MAP kinase signaling. Studies by our group and others demonstrate that RAP GTPases, in particular RAP1A and RAP1B, are the key molecular switches that turn on platelet activation/adhesiveness at sites of injury. In this review, we will summarize major findings on the role of RAP GTPases in platelet biology with a focus on the signaling pathways leading to the conversion of integrins to a high-affinity state.
Collapse
Affiliation(s)
- Lucia Stefanini
- Department of Internal Medicine and Medical Specialties, Sapienza University of Rome, Rome, Italy
| | - Wolfgang Bergmeier
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill (NC), USA
- McAllister Heart Institute, University of North Carolina at Chapel Hill (NC), USA
| |
Collapse
|
10
|
Nakhaei-Rad S, Haghighi F, Nouri P, Rezaei Adariani S, Lissy J, Kazemein Jasemi NS, Dvorsky R, Ahmadian MR. Structural fingerprints, interactions, and signaling networks of RAS family proteins beyond RAS isoforms. Crit Rev Biochem Mol Biol 2018; 53:130-156. [PMID: 29457927 DOI: 10.1080/10409238.2018.1431605] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Saeideh Nakhaei-Rad
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Fereshteh Haghighi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Parivash Nouri
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Soheila Rezaei Adariani
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Jana Lissy
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Neda S Kazemein Jasemi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Radovan Dvorsky
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Mohammad Reza Ahmadian
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| |
Collapse
|
11
|
Rehmann H. Interaction of Epac with Non-canonical Cyclic Nucleotides. Handb Exp Pharmacol 2017; 238:135-147. [PMID: 27900608 DOI: 10.1007/164_2015_37] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epac1 and Epac2 are cyclic nucleotide-binding (CNB) domain containing proteins, which were originally identified as cAMP-regulated guanine nucleotide exchange factors (GEFs) for the small G-protein Rap. Therefore, Epac proteins founded next to protein kinase A (PKA) and cyclic nucleotide-regulated ion channels the third group of cAMP-responsive proteins in higher organisms. Epac proteins are involved in the regulation of several physiological processes. In particular Epac1 mediates the regulation of molecular processes underlying cell adhesion and mobility. In the pancreas activation of Epac2 potentiates the release of glucose-induced insulin secretion and received attention as a putative target for antidiabetic treatment. While the regulation of Epac by cAMP has been analysed in structural and biochemical detail, less is known on the interaction of Epac with non-canonical cyclic nucleotides. This chapter will discuss to what extent other cyclic purines than cAMP or cyclic pyrimidine could act as Epac agonists or antagonists. The focus will be on the biophysical analysis of the interaction between Epac and these cyclic nucleotides.
Collapse
Affiliation(s)
- Holger Rehmann
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands.
| |
Collapse
|
12
|
Vercoulen Y, Kondo Y, Iwig JS, Janssen AB, White KA, Amini M, Barber DL, Kuriyan J, Roose JP. A Histidine pH sensor regulates activation of the Ras-specific guanine nucleotide exchange factor RasGRP1. eLife 2017; 6:29002. [PMID: 28952923 PMCID: PMC5643099 DOI: 10.7554/elife.29002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 09/05/2017] [Indexed: 02/04/2023] Open
Abstract
RasGRPs are guanine nucleotide exchange factors that are specific for Ras or Rap, and are important regulators of cellular signaling. Aberrant expression or mutation of RasGRPs results in disease. An analysis of RasGRP1 SNP variants led to the conclusion that the charge of His 212 in RasGRP1 alters signaling activity and plasma membrane recruitment, indicating that His 212 is a pH sensor that alters the balance between the inactive and active forms of RasGRP1. To understand the structural basis for this effect we compared the structure of autoinhibited RasGRP1, determined previously, to those of active RasGRP4:H-Ras and RasGRP2:Rap1b complexes. The transition from the autoinhibited to the active form of RasGRP1 involves the rearrangement of an inter-domain linker that displaces inhibitory inter-domain interactions. His 212 is located at the fulcrum of these conformational changes, and structural features in its vicinity are consistent with its function as a pH-dependent switch.
Collapse
Affiliation(s)
- Yvonne Vercoulen
- Department of Anatomy, University of California, San Francisco, San Francisco, United States.,Molecular Cancer Research, Center for Molecular Medicine, UMC Utrecht, Utrecht University, Utrecht, Netherlands
| | - Yasushi Kondo
- Department of Molecular and Cell Biology and Chemistry, University of California, Berkeley, United States.,California Institute for Quantitative Biosciences, University of California, Berkeley, United States
| | - Jeffrey S Iwig
- Department of Molecular and Cell Biology and Chemistry, University of California, Berkeley, United States.,California Institute for Quantitative Biosciences, University of California, Berkeley, United States
| | - Axel B Janssen
- Department of Anatomy, University of California, San Francisco, San Francisco, United States
| | - Katharine A White
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - Mojtaba Amini
- Molecular Cancer Research, Center for Molecular Medicine, UMC Utrecht, Utrecht University, Utrecht, Netherlands
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - John Kuriyan
- Department of Molecular and Cell Biology and Chemistry, University of California, Berkeley, United States.,California Institute for Quantitative Biosciences, University of California, Berkeley, United States.,Howard Hughes Medical Institute, University of California, Berkeley, United States.,Department of Chemistry, University of California, Berkeley, United States.,Divisions of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, United States
| | - Jeroen P Roose
- Department of Anatomy, University of California, San Francisco, San Francisco, United States
| |
Collapse
|
13
|
Ren J, Cook AA, Bergmeier W, Sondek J. A negative-feedback loop regulating ERK1/2 activation and mediated by RasGPR2 phosphorylation. Biochem Biophys Res Commun 2016; 474:193-198. [PMID: 27107697 DOI: 10.1016/j.bbrc.2016.04.100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 04/19/2016] [Indexed: 10/21/2022]
Abstract
The dynamic regulation of ERK1 and -2 (ERK1/2) is required for precise signal transduction controlling cell proliferation, differentiation, and survival. However, the underlying mechanisms regulating the activation of ERK1/2 are not completely understood. In this study, we show that phosphorylation of RasGRP2, a guanine nucleotide exchange factor (GEF), inhibits its ability to activate the small GTPase Rap1 that ultimately leads to decreased activation of ERK1/2 in cells. ERK2 phosphorylates RasGRP2 at Ser394 located in the linker region implicated in its autoinhibition. These studies identify RasGRP2 as a novel substrate of ERK1/2 and define a negative-feedback loop that regulates the BRaf-MEK-ERK signaling cascade. This negative-feedback loop determines the amplitude and duration of active ERK1/2.
Collapse
Affiliation(s)
- Jinqi Ren
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| | - Aaron A Cook
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| | - Wolfgang Bergmeier
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| | - John Sondek
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599.,Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599.,Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| |
Collapse
|
14
|
Popovic M, Schouten A, Rensen-de Leeuw M, Rehmann H. The structure of the Guanine Nucleotide Exchange Factor Rlf in complex with the small G-protein Ral identifies conformational intermediates of the exchange reaction and the basis for the selectivity. J Struct Biol 2016; 193:106-14. [DOI: 10.1016/j.jsb.2015.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 12/04/2015] [Accepted: 12/11/2015] [Indexed: 11/28/2022]
|
15
|
Mechanisms of isoform specific Rap2 signaling during enterocytic brush border formation. PLoS One 2014; 9:e106687. [PMID: 25203140 PMCID: PMC4159233 DOI: 10.1371/journal.pone.0106687] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/08/2014] [Indexed: 01/01/2023] Open
Abstract
Brush border formation during polarity establishment of intestinal epithelial cells is uniquely governed by the Rap2A GTPase, despite expression of the other highly similar Rap2 isoforms (Rap2B and Rap2C). We investigated the mechanisms of this remarkable specificity and found that Rap2C is spatially segregated from Rap2A signaling as it is not enriched at the apical membrane after polarization. In contrast, both Rap2A and Rap2B are similarly located at Rab11 positive apical recycling endosomes and inside the brush border. However, although Rap2B localizes similarly it is not equally activated as Rap2A during brush border formation. We reveal that the C-terminal hypervariable region allows selective activation of Rap2A, yet this selectivity does not originate from the known differential lipid modifications of this region. In conclusion, we demonstrate that Rap2 specificity during brush border formation is determined by two distinct mechanisms involving segregated localization and selective activation.
Collapse
|