1
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Peruzzi JA, Gunnels TF, Edelstein HI, Lu P, Baker D, Leonard JN, Kamat NP. Enhancing extracellular vesicle cargo loading and functional delivery by engineering protein-lipid interactions. Nat Commun 2024; 15:5618. [PMID: 38965227 PMCID: PMC11224323 DOI: 10.1038/s41467-024-49678-z] [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: 04/29/2023] [Accepted: 06/13/2024] [Indexed: 07/06/2024] Open
Abstract
Naturally generated lipid nanoparticles termed extracellular vesicles (EVs) hold significant promise as engineerable therapeutic delivery vehicles. However, active loading of protein cargo into EVs in a manner that is useful for delivery remains a challenge. Here, we demonstrate that by rationally designing proteins to traffic to the plasma membrane and associate with lipid rafts, we can enhance loading of protein cargo into EVs for a set of structurally diverse transmembrane and peripheral membrane proteins. We then demonstrate the capacity of select lipid tags to mediate increased EV loading and functional delivery of an engineered transcription factor to modulate gene expression in target cells. We envision that this technology could be leveraged to develop new EV-based therapeutics that deliver a wide array of macromolecular cargo.
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Affiliation(s)
- Justin A Peruzzi
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Taylor F Gunnels
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Hailey I Edelstein
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Peilong Lu
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Joshua N Leonard
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA.
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA.
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, 60208, USA.
- Member, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, IL, 60208, USA.
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, 60208, USA.
| | - Neha P Kamat
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA.
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA.
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, 60208, USA.
- Member, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, IL, 60208, USA.
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, 60208, USA.
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2
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Page ML, Aguzzoli Heberle B, Brandon JA, Wadsworth ME, Gordon LA, Nations KA, Ebbert MTW. Surveying the landscape of RNA isoform diversity and expression across 9 GTEx tissues using long-read sequencing data. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.579945. [PMID: 38405825 PMCID: PMC10888753 DOI: 10.1101/2024.02.13.579945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Even though alternative RNA splicing was discovered nearly 50 years ago (1977), we still understand very little about most isoforms arising from a single gene, including in which tissues they are expressed and if their functions differ. Human gene annotations suggest remarkable transcriptional complexity, with approximately 252,798 distinct RNA isoform annotations from 62,710 gene bodies (Ensembl v109; 2023), emphasizing the need to understand their biological effects. For example, 256 gene bodies have ≥50 annotated isoforms and 30 have ≥100, where one protein-coding gene (MAPK10) even has 192 distinct RNA isoform annotations. Whether such isoform diversity results from biological redundancy or spurious alternative splicing (i.e., noise), or whether individual isoforms have specialized functions (even if subtle) remains a mystery for most genes. Recent studies by Aguzzoli-Heberle et al., Leung et al., and Glinos et al. demonstrated long-read RNAseq enables improved RNA isoform quantification for essentially any tissue, cell type, or biological condition (e.g., disease, development, aging, etc.), making it possible to better assess individual isoform expression and function. While each study provided important discoveries related to RNA isoform diversity, deeper exploration is needed. We sought to quantify and characterize real isoform usage across tissues (compared to annotations). We used long-read RNAseq data from 58 GTEx samples across nine tissues (three brain, two heart, muscle, lung, liver, and cultured fibroblasts) generated by Glinos et al. and found considerable isoform diversity within and across tissues. Cerebellar hemisphere was the most transcriptionally complex tissue (22,522 distinct isoforms; 3,726 unique); liver was least diverse (12,435 distinct isoforms; 1,039 unique). We highlight gene clusters exhibiting high tissue-specific isoform diversity per tissue (e.g., TPM1 expresses 19 in heart's atrial appendage). We also validated 447 of the 700 new isoforms discovered by Aguzzoli-Heberle et al. and found that 88 were expressed in all nine tissues, while 58 were specific to a single tissue. This study represents a broad survey of the RNA isoform landscape, demonstrating isoform diversity across nine tissues and emphasizes the need to better understand how individual isoforms from a single gene body contribute to human health and disease.
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Affiliation(s)
- Madeline L. Page
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Bernardo Aguzzoli Heberle
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - J. Anthony Brandon
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Mark E. Wadsworth
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Lacey A. Gordon
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Kayla A. Nations
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Mark T. W. Ebbert
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
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3
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Gimeno-Valiente F, López-Rodas G, Castillo J, Franco L. The Many Roads from Alternative Splicing to Cancer: Molecular Mechanisms Involving Driver Genes. Cancers (Basel) 2024; 16:2123. [PMID: 38893242 PMCID: PMC11171328 DOI: 10.3390/cancers16112123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 05/29/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
Cancer driver genes are either oncogenes or tumour suppressor genes that are classically activated or inactivated, respectively, by driver mutations. Alternative splicing-which produces various mature mRNAs and, eventually, protein variants from a single gene-may also result in driving neoplastic transformation because of the different and often opposed functions of the variants of driver genes. The present review analyses the different alternative splicing events that result in driving neoplastic transformation, with an emphasis on their molecular mechanisms. To do this, we collected a list of 568 gene drivers of cancer and revised the literature to select those involved in the alternative splicing of other genes as well as those in which its pre-mRNA is subject to alternative splicing, with the result, in both cases, of producing an oncogenic isoform. Thirty-one genes fall into the first category, which includes splicing factors and components of the spliceosome and splicing regulators. In the second category, namely that comprising driver genes in which alternative splicing produces the oncogenic isoform, 168 genes were found. Then, we grouped them according to the molecular mechanisms responsible for alternative splicing yielding oncogenic isoforms, namely, mutations in cis splicing-determining elements, other causes involving non-mutated cis elements, changes in splicing factors, and epigenetic and chromatin-related changes. The data given in the present review substantiate the idea that aberrant splicing may regulate the activation of proto-oncogenes or inactivation of tumour suppressor genes and details on the mechanisms involved are given for more than 40 driver genes.
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Affiliation(s)
- Francisco Gimeno-Valiente
- Cancer Evolution and Genome Instability Laboratory, University College London Cancer Institute, London WC1E 6DD, UK;
| | - Gerardo López-Rodas
- Department of Oncology, Institute of Health Research INCLIVA, 46010 Valencia, Spain; (G.L.-R.); (J.C.)
- Department of Biochemistry and Molecular Biology, Universitat de València, 46010 Valencia, Spain
| | - Josefa Castillo
- Department of Oncology, Institute of Health Research INCLIVA, 46010 Valencia, Spain; (G.L.-R.); (J.C.)
- Department of Biochemistry and Molecular Biology, Universitat de València, 46010 Valencia, Spain
- Centro de Investigación Biomédica en Red en Cáncer (CIBERONC), 28029 Madrid, Spain
| | - Luis Franco
- Department of Oncology, Institute of Health Research INCLIVA, 46010 Valencia, Spain; (G.L.-R.); (J.C.)
- Department of Biochemistry and Molecular Biology, Universitat de València, 46010 Valencia, Spain
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4
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Kjer-Hansen P, Weatheritt RJ. The function of alternative splicing in the proteome: rewiring protein interactomes to put old functions into new contexts. Nat Struct Mol Biol 2023; 30:1844-1856. [PMID: 38036695 DOI: 10.1038/s41594-023-01155-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 10/17/2023] [Indexed: 12/02/2023]
Abstract
Alternative splicing affects more than 95% of multi-exon genes in the human genome. These changes affect the proteome in a myriad of ways. Here, we review our understanding of the breadth of these changes from their effect on protein structure to their influence on interactions. These changes encompass effects on nucleic acid binding in the nucleus to protein-carbohydrate interactions in the extracellular milieu, altering interactions involving all major classes of biological molecules. Protein isoforms have profound influences on cellular and tissue physiology, for example, by shaping neuronal connections, enhancing insulin secretion by pancreatic beta cells and allowing for alternative viral defense strategies in stem cells. More broadly, alternative splicing enables repurposing proteins from one context to another and thereby contributes to both the evolution of new traits as well as the creation of disease-specific interactomes that drive pathological phenotypes. In this Review, we highlight this universal character of alternative splicing as a central regulator of protein function with implications for almost every biological process.
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Affiliation(s)
- Peter Kjer-Hansen
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
- St. Vincent Clinical School, University of New South Wales, Darlinghurst, New South Wales, Australia.
| | - Robert J Weatheritt
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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5
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Justyna K, Das R, Lorimer EL, Hu J, Pedersen JS, Sprague-Getsy AM, Schey GL, Sieburg MA, Koehn OJ, Wang YC, Chen YX, Hougland JL, Williams CL, Distefano MD. Synthesis, Enzymatic Peptide Incorporation, and Applications of Diazirine-Containing Isoprenoid Diphosphate Analogues. Org Lett 2023; 25:6767-6772. [PMID: 37669435 PMCID: PMC10755972 DOI: 10.1021/acs.orglett.3c02736] [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] [Indexed: 09/07/2023]
Abstract
Prenylated proteins contain C15 or C20 isoprenoids linked to cysteine residues positioned near their C-termini. Here we describe the preparation of isoprenoid diphosphate analogues incorporating diazirine groups that can be used to probe interactions between prenylated proteins and other proteins that interact with them. Studies using synthetic peptides and whole proteins demonstrate that these diazirine analogues are efficient substrates for prenyltransferases. Photo-cross-linking experiments using peptides incorporating the diazirine-functionalized isoprenoids selectively cross-link to several different proteins. These new isoprenoid analogues should be broadly useful in the studies of protein prenylation.
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Affiliation(s)
- Katarzyna Justyna
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Riki Das
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ellen L. Lorimer
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226; Cancer Center, Medical College of Wisconsin,Milwaukee, WI 53226, USA
| | - Jiayue Hu
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jodi S. Pedersen
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Garrett L. Schey
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Olivia J. Koehn
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226; Cancer Center, Medical College of Wisconsin,Milwaukee, WI 53226, USA
| | - Yen-Chih Wang
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yong-Xiang Chen
- Department Chemistry, Tsinghua University, Beijing, 100084, China
| | - James L. Hougland
- Department of Chemistry, Syracuse University, Syracuse, NY 13244, USA
| | - Carol L. Williams
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226; Cancer Center, Medical College of Wisconsin,Milwaukee, WI 53226, USA
| | - Mark D. Distefano
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
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6
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Jung D, Bachmann HS. Regulation of protein prenylation. Biomed Pharmacother 2023; 164:114915. [PMID: 37236024 DOI: 10.1016/j.biopha.2023.114915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
Prenyltransferases (PTases) are known to play a role in embryonic development, normal tissue homeostasis and cancer by posttranslationally modifying proteins involved in these processes. They are being discussed as potential drug targets in an increasing number of diseases, ranging from Alzheimer's disease to malaria. Protein prenylation and the development of specific PTase inhibitors (PTIs) have been subject to intense research in recent decades. Recently, the FDA approved lonafarnib, a specific farnesyltransferase inhibitor that acts directly on protein prenylation; and bempedoic acid, an ATP citrate lyase inhibitor that might alter intracellular isoprenoid composition, the relative concentrations of which can exert a decisive influence on protein prenylation. Both drugs represent the first approved agent in their respective substance class. Furthermore, an overwhelming number of processes and proteins that regulate protein prenylation have been identified over the years, many of which have been proposed as molecular targets for pharmacotherapy in their own right. However, certain aspects of protein prenylation, such as the regulation of PTase gene expression or the modulation of PTase activity by phosphorylation, have attracted less attention, despite their reported influence on tumor cell proliferation. Here, we want to summarize the advances regarding our understanding of the regulation of protein prenylation and the potential implications for drug development. Additionally, we want to suggest new lines of investigation that encompass the search for regulatory elements for PTases, especially at the genetic and epigenetic levels.
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Affiliation(s)
- Dominik Jung
- Institute of Pharmacology and Toxicology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Hagen S Bachmann
- Institute of Pharmacology and Toxicology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany.
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7
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Koehn OJ, Lorimer E, Unger B, Harris R, Das AS, Suazo KF, Auger S, Distefano M, Prokop JW, Williams CL. GTPase splice variants RAC1 and RAC1B display isoform-specific differences in localization, prenylation, and interaction with the chaperone protein SmgGDS. J Biol Chem 2023; 299:104698. [PMID: 37059183 DOI: 10.1016/j.jbc.2023.104698] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 04/16/2023] Open
Abstract
Identifying events that regulate the prenylation and localization of small GTPases will help define new strategies for therapeutic targeting of these proteins in disorders such as cancer, cardiovascular disease, and neurological deficits. Splice variants of the chaperone protein SmgGDS (encoded by RAP1GDS1) are known to regulate prenylation and trafficking of small GTPases. The SmgGDS-607 splice variant regulates prenylation by binding pre-prenylated small GTPases, but the effects of SmgGDS binding to the small GTPase RAC1 versus the splice variant RAC1B are not well defined. Here we report unexpected differences in the prenylation and localization of RAC1 and RAC1B, and their binding to SmgGDS. Compared to RAC1, RAC1B more stably associates with SmgGDS-607, is less prenylated, and accumulates more in the nucleus. We show that the small GTPase DIRAS1 inhibits binding of RAC1 and RAC1B to SmgGDS and reduces their prenylation. These results suggest that prenylation of RAC1 and RAC1B is facilitated by binding to SmgGDS-607, but the greater retention of RAC1B by SmgGDS-607 slows RAC1B prenylation. We show that inhibiting RAC1 prenylation by mutating the CAAX motif promotes RAC1 nuclear accumulation, suggesting that differences in prenylation contribute to the different nuclear localization of RAC1 versus RAC1B. Finally, we demonstrate RAC1 and RAC1B that cannot be prenylated bind GTP in cells, indicating that prenylation is not a prerequisite for activation. We report differential expression of RAC1 and RAC1B transcripts in tissues, consistent with these two splice variants having unique functions that might arise in part from their differences in prenylation and localization.
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Affiliation(s)
- Olivia J Koehn
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Ellen Lorimer
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Bethany Unger
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Ra'Mal Harris
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI, 49503, USA
| | - Akansha S Das
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI, 49503, USA
| | - Kiall F Suazo
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USAA
| | - Shelby Auger
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USAA
| | - Mark Distefano
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USAA
| | - Jeremy W Prokop
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI, 49503, USA; Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, 48824, USA
| | - Carol L Williams
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
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8
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Michalak DJ, Unger B, Lorimer E, Grishaev A, Williams CL, Heinrich F, Lösche M. Structural and biophysical properties of farnesylated KRas interacting with the chaperone SmgGDS-558. Biophys J 2022; 121:3684-3697. [PMID: 35614853 PMCID: PMC9617131 DOI: 10.1016/j.bpj.2022.05.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 05/02/2022] [Accepted: 05/19/2022] [Indexed: 11/26/2022] Open
Abstract
KRas is a small GTPase and membrane-bound signaling protein. Newly synthesized KRas is post-translationally modified with a membrane-anchoring prenyl group. KRas chaperones are therapeutic targets in cancer due to their participation in trafficking oncogenic KRas to membranes. SmgGDS splice variants are chaperones for small GTPases with basic residues in their hypervariable domain (HVR), including KRas. SmgGDS-607 escorts pre-prenylated small GTPases, while SmgGDS-558 escorts prenylated small GTPases. We provide a structural description of farnesylated and fully processed KRas (KRas-FMe) in complex with SmgGDS-558 and define biophysical properties of this interaction. Surface plasmon resonance measurements on biomimetic model membranes quantified the thermodynamics of the interaction of SmgGDS with KRas, and small-angle x-ray scattering was used to characterize complexes of SmgGDS-558 and KRas-FMe structurally. Structural models were refined using Monte Carlo and molecular dynamics simulations. Our results indicate that SmgGDS-558 interacts with the HVR and the farnesylated C-terminus of KRas-FMe, but not its G-domain. Therefore, SmgGDS-558 interacts differently with prenylated KRas than prenylated RhoA, whose G-domain was found in close contact with SmgGDS-558 in a recent crystal structure. Using immunoprecipitation assays, we show that SmgGDS-558 binds the GTP-bound, GDP-bound, and nucleotide-free forms of farnesylated and fully processed KRas in cells, consistent with SmgGDS-558 not engaging the G-domain of KRas. We found that the dissociation constant, Kd, for KRas-FMe binding to SmgGDS-558 is comparable with that for the KRas complex with PDEδ, a well-characterized KRas chaperone that also does not interact with the KRas G-domain. These results suggest that KRas interacts in similar ways with the two chaperones SmgGDS-558 and PDEδ. Therapeutic targeting of the SmgGDS-558/KRas complex might prove as useful as targeting the PDEδ/KRas complex in KRas-driven cancers.
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Affiliation(s)
- Dennis J Michalak
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Bethany Unger
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ellen Lorimer
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Alexander Grishaev
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland; Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland
| | - Carol L Williams
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Frank Heinrich
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania; Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland.
| | - Mathias Lösche
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania; Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland
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9
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Jaimon E, Tripathi A, Khurana A, Ghosh D, Sugatha J, Datta S. Binding with heat shock cognate protein HSC70 fine-tunes the Golgi association of the small GTPase ARL5B. J Biol Chem 2021; 297:101422. [PMID: 34798070 PMCID: PMC8661063 DOI: 10.1016/j.jbc.2021.101422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/04/2021] [Accepted: 11/08/2021] [Indexed: 12/30/2022] Open
Abstract
ARL5B, an ARF-like small GTPase localized to the trans-Golgi, is known for regulating endosome-Golgi trafficking and promoting the migration and invasion of breast cancer cells. Although a few interacting partners have been identified, the mechanism of the shuttling of ARL5B between the Golgi membrane and the cytosol is still obscure. Here, using GFP-binding protein (GBP) pull-down followed by mass spectrometry, we identified heat shock cognate protein (HSC70) as an additional interacting partner of ARL5B. Our pull-down and isothermal titration calorimetry (ITC)-based studies suggested that HSC70 binds to ARL5B in an ADP-dependent manner. Additionally, we showed that the N-terminal helix and the nucleotide status of ARL5B contribute to its recognition by HSC70. The confocal microscopy and cell fractionation studies in MDA-MB-231 breast cancer cells revealed that the depletion of HSC70 reduces the localization of ARL5B to the Golgi. Using in vitro reconstitution approach, we provide evidence that HSC70 fine-tunes the association of ARL5B with Golgi membrane. Finally, we demonstrated that the interaction between ARL5B and HSC70 is important for the localization of cation independent mannose-6-phosphate receptor (CIMPR) at Golgi. Collectively, we propose a mechanism by which HSC70, a constitutively expressed chaperone, modulates the Golgi association of ARL5B, which in turn has implications for the Golgi-associated functions of this GTPase.
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Affiliation(s)
- Ebsy Jaimon
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Aashutosh Tripathi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Arohi Khurana
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Dipanjana Ghosh
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Jini Sugatha
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Sunando Datta
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India.
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10
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Campbell SL, Philips MR. Post-translational modification of RAS proteins. Curr Opin Struct Biol 2021; 71:180-192. [PMID: 34365229 DOI: 10.1016/j.sbi.2021.06.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 06/25/2021] [Indexed: 11/26/2022]
Abstract
Mutations of RAS genes drive cancer more frequently than any other oncogene. RAS proteins integrate signals from a wide array of receptors and initiate downstream signaling through pathways that control cellular growth. RAS proteins are fundamentally binary molecular switches in which the off/on state is determined by the binding of GDP or GTP, respectively. As such, the intrinsic and regulated nucleotide-binding and hydrolytic properties of the RAS GTPase were historically believed to account for the entirety of the regulation of RAS signaling. However, it is increasingly clear that RAS proteins are also regulated by a vast array of post-translational modifications (PTMs). The current challenge is to understand what are the functional consequences of these modifications and which are physiologically relevant. Because PTMs are catalyzed by enzymes that may offer targets for drug discovery, the study of RAS PTMs has been a high priority for RAS biologists.
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Affiliation(s)
| | - Mark R Philips
- Perlmutter Cancer Center, NYU Grossman School of Medicine, USA
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11
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Wang WH, Yuan T, Qian MJ, Yan FJ, Yang L, He QJ, Yang B, Lu JJ, Zhu H. Post-translational modification of KRAS: potential targets for cancer therapy. Acta Pharmacol Sin 2021; 42:1201-1211. [PMID: 33087838 PMCID: PMC8285426 DOI: 10.1038/s41401-020-00542-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 09/16/2020] [Indexed: 02/02/2023] Open
Abstract
Aberrant activation of the RAS superfamily is one of the critical factors in carcinogenesis. Among them, KRAS is the most frequently mutated one which has inspired extensive studies for developing approaches to intervention. Although the cognition toward KRAS remains far from complete, mounting evidence suggests that a variety of post-translational modifications regulate its activation and localization. In this review, we summarize the regulatory mode of post-translational modifications on KRAS including prenylation, post-prenylation, palmitoylation, ubiquitination, phosphorylation, SUMOylation, acetylation, nitrosylation, etc. We also highlight the recent studies targeting these modifications having exhibited potent anti-tumor activities.
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Affiliation(s)
- Wei-Hua Wang
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Tao Yuan
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Mei-Jia Qian
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Fang-Jie Yan
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Liu Yang
- Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, 310014, China
| | - Qiao-Jun He
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Bo Yang
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Jin-Jian Lu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
| | - Hong Zhu
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China.
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12
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Jbara A, Siegfried Z, Karni R. Splice-switching as cancer therapy. Curr Opin Pharmacol 2021; 59:140-148. [PMID: 34217945 DOI: 10.1016/j.coph.2021.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/26/2022]
Abstract
In light of recent advances in RNA splicing modulation as therapy for specific genetic diseases, there is great optimism that this approach can be applied to treatment of cancer as well. Dysregulation of alternative RNA splicing is a common aberration detected in many cancers and thus, provides an attractive target for therapeutics. Here, we present and compare two promising approaches that are currently being investigated to manipulate alternative splicing and their potential use in therapy. The first strategy makes use of splice-switching oligonucleotides, whereas the second strategy uses CRISPR (clustered regularly interspaced short palindromic repeat Cas (CRISPR-associated) technology. We will discuss both the challenges and limitations of these technologies and progress being made to implement splice-switching as a potential cancer therapy.
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Affiliation(s)
- Amina Jbara
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, 91120, Israel
| | - Zahava Siegfried
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, 91120, Israel
| | - Rotem Karni
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, 91120, Israel.
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13
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Suazo KF, Park KY, Distefano MD. A Not-So-Ancient Grease History: Click Chemistry and Protein Lipid Modifications. Chem Rev 2021; 121:7178-7248. [PMID: 33821625 PMCID: PMC8820976 DOI: 10.1021/acs.chemrev.0c01108] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein lipid modification involves the attachment of hydrophobic groups to proteins via ester, thioester, amide, or thioether linkages. In this review, the specific click chemical reactions that have been employed to study protein lipid modification and their use for specific labeling applications are first described. This is followed by an introduction to the different types of protein lipid modifications that occur in biology. Next, the roles of click chemistry in elucidating specific biological features including the identification of lipid-modified proteins, studies of their regulation, and their role in diseases are presented. A description of the use of protein-lipid modifying enzymes for specific labeling applications including protein immobilization, fluorescent labeling, nanostructure assembly, and the construction of protein-drug conjugates is presented next. Concluding remarks and future directions are presented in the final section.
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Affiliation(s)
- Kiall F. Suazo
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455 USA
| | - Keun-Young Park
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455 USA
| | - Mark D. Distefano
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455 USA
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14
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Brandt AC, Koehn OJ, Williams CL. SmgGDS: An Emerging Master Regulator of Prenylation and Trafficking by Small GTPases in the Ras and Rho Families. Front Mol Biosci 2021; 8:685135. [PMID: 34222337 PMCID: PMC8242357 DOI: 10.3389/fmolb.2021.685135] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/27/2021] [Indexed: 11/17/2022] Open
Abstract
Newly synthesized small GTPases in the Ras and Rho families are prenylated by cytosolic prenyltransferases and then escorted by chaperones to membranes, the nucleus, and other sites where the GTPases participate in a variety of signaling cascades. Understanding how prenylation and trafficking are regulated will help define new therapeutic strategies for cancer and other disorders involving abnormal signaling by these small GTPases. A growing body of evidence indicates that splice variants of SmgGDS (gene name RAP1GDS1) are major regulators of the prenylation, post-prenylation processing, and trafficking of Ras and Rho family members. SmgGDS-607 binds pre-prenylated small GTPases, while SmgGDS-558 binds prenylated small GTPases. This review discusses the history of SmgGDS research and explains our current understanding of how SmgGDS splice variants regulate the prenylation and trafficking of small GTPases. We discuss recent evidence that mutant forms of RabL3 and Rab22a control the release of small GTPases from SmgGDS, and review the inhibitory actions of DiRas1, which competitively blocks the binding of other small GTPases to SmgGDS. We conclude with a discussion of current strategies for therapeutic targeting of SmgGDS in cancer involving splice-switching oligonucleotides and peptide inhibitors.
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Affiliation(s)
- Anthony C Brandt
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Olivia J Koehn
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Carol L Williams
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, United States
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15
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Kelly MR, Kostyrko K, Han K, Mooney NA, Jeng EE, Spees K, Dinh PT, Abbott KL, Gwinn DM, Sweet-Cordero EA, Bassik MC, Jackson PK. Combined Proteomic and Genetic Interaction Mapping Reveals New RAS Effector Pathways and Susceptibilities. Cancer Discov 2020; 10:1950-1967. [PMID: 32727735 PMCID: PMC7710624 DOI: 10.1158/2159-8290.cd-19-1274] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 06/08/2020] [Accepted: 07/24/2020] [Indexed: 11/16/2022]
Abstract
Activating mutations in RAS GTPases drive many cancers, but limited understanding of less-studied RAS interactors, and of the specific roles of different RAS interactor paralogs, continues to limit target discovery. We developed a multistage discovery and screening process to systematically identify genes conferring RAS-related susceptibilities in lung adenocarcinoma. Using affinity purification mass spectrometry, we generated a protein-protein interaction map of RAS interactors and pathway components containing hundreds of interactions. From this network, we constructed a CRISPR dual knockout library targeting 119 RAS-related genes that we screened for KRAS-dependent genetic interactions (GI). This approach identified new RAS effectors, including the adhesion controller RADIL and the endocytosis regulator RIN1, and >250 synthetic lethal GIs, including a potent KRAS-dependent interaction between RAP1GDS1 and RHOA. Many GIs link specific paralogs within and between gene families. These findings illustrate the power of multiomic approaches to uncover synthetic lethal combinations specific for hitherto untreatable cancer genotypes. SIGNIFICANCE: We establish a deep network of protein-protein and genetic interactions in the RAS pathway. Many interactions validated here demonstrate important specificities and redundancies among paralogous RAS regulators and effectors. By comparing synthetic lethal interactions across KRAS-dependent and KRAS-independent cell lines, we identify several new combination therapy targets for RAS-driven cancers.This article is highlighted in the In This Issue feature, p. 1775.
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Affiliation(s)
- Marcus R Kelly
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California.,Program in Cancer Biology, Stanford University School of Medicine, Stanford, California
| | - Kaja Kostyrko
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - Kyuho Han
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Nancie A Mooney
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California
| | - Edwin E Jeng
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Kaitlyn Spees
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Phuong T Dinh
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - Keene L Abbott
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California
| | - Dana M Gwinn
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - E Alejandro Sweet-Cordero
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, San Francisco, California.
| | - Michael C Bassik
- Department of Genetics, Stanford University School of Medicine, Stanford, California. .,Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, Stanford, California
| | - Peter K Jackson
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California. .,Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, Stanford, California.,Department of Pathology, Stanford University School of Medicine, Stanford, California
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16
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Liao D, Zhong L, Yin J, Zeng C, Wang X, Huang X, Chen J, Zhang H, Zhang R, Guan XY, Shuai X, Sui J, Gao S, Deng W, Zeng YX, Shen JN, Chen J, Kang T. Chromosomal translocation-derived aberrant Rab22a drives metastasis of osteosarcoma. Nat Cell Biol 2020; 22:868-881. [PMID: 32483387 DOI: 10.1038/s41556-020-0522-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/16/2020] [Indexed: 01/04/2023]
Abstract
Osteosarcoma is a type of aggressive malignant bone tumour that frequently metastasizes to lungs, resulting in poor prognosis. However, the molecular mechanisms of lung metastasis of osteosarcoma remain poorly understood. Here we identify exon-intron fusion genes in osteosarcoma cell lines and tissues. These fusion genes are derived from chromosomal translocations that juxtapose the coding region for amino acids 1-38 of Rab22a (Rab22a1-38) with multiple inverted introns and untranslated regions of chromosome 20. The resulting translation products, designated Rab22a-NeoFs, acquire the ability to drive lung metastasis of osteosarcoma. The Rab22a1-38 moiety governs the function of Rab22a-NeoFs by binding to SmgGDS-607, a GTP-GDP exchange factor of RhoA. This association facilitates the release of GTP-bound RhoA from SmgGDS-607, which induces increased activity of RhoA and promotes metastasis. Disrupting the interaction between Rab22a-NeoF1 and SmgGDS-607 with a synthetic peptide prevents lung metastasis in an orthotopic model of osteosarcoma. Our findings may provide a promising strategy for a subset of osteosarcoma patients with lung metastases.
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Affiliation(s)
- Dan Liao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Li Zhong
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Junqiang Yin
- Department of Musculoskeletal Oncology, First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Cuiling Zeng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xin Wang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | | | - Jinna Chen
- Department of Clinical Oncology, The University of Hong Kong, Hong Kong, China
| | - Hong Zhang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Ruhua Zhang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xin-Yuan Guan
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Clinical Oncology, The University of Hong Kong, Hong Kong, China
| | - Xintao Shuai
- School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - Jianhua Sui
- National Institute of Biological Sciences, Beijing, China
| | - Song Gao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Wuguo Deng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Yi-Xin Zeng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jing-Nan Shen
- Department of Musculoskeletal Oncology, First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
| | - Jian Chen
- Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, China.
| | - Tiebang Kang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China.
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17
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Asiri A, Aloyouni E, Umair M, Alyafee Y, Al Tuwaijri A, Alhamoudi KM, Almuzzaini B, Al Baz A, Alwadaani D, Nashabat M, Alfadhel M. Mutated RAP1GDS1 causes a new syndrome of dysmorphic feature, intellectual disability & speech delay. Ann Clin Transl Neurol 2020; 7:956-964. [PMID: 32431071 PMCID: PMC7318102 DOI: 10.1002/acn3.51059] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 04/01/2020] [Accepted: 04/27/2020] [Indexed: 01/12/2023] Open
Abstract
Background RAP1GDS1 (RAP1, GTP‐GDP dissociation stimulator 1), also known as SmgGDS, is a guanine nucleotide exchange factor (GEF) that regulates small GTPases, including, RHOA, RAC1, and KRAS. RAP1GDS1 was shown to be highly expressed in different tissue types including the brain. However, mutations in the RAP1GDS1 gene associated with human diseases have not previously been reported. Methods We report on four affected individuals, presenting intellectual disability, global developmental delay (GDD), and hypotonia. The probands’ DNA was subjected to whole‐genome sequencing, revealing a homozygous splice acceptor site mutation in the RAP1GDS1 gene (1444‐1G > A). Sanger sequencing was performed to confirm the segregation of the variant in two Saudi families. The possible aberrant splicing in the patients’ RNA was investigated using RT‐PCR and changes in mRNA expression of the patients were confirmed using qRT‐PCR. Results The identified splice variant was found to segregate within the two families. RT‐PCR showed that the mutation affected RAP1GDS1 gene splicing, resulting in the production of aberrant transcripts in the affected individuals. Quantitative gene expression analysis demonstrated that the RAP1GDS1 mRNA expression in all the probands was significantly decreased compared to that of the control, and Sanger sequencing of the probands’ cDNA revealed skipping of exon 13, further strengthening the pathogenicity of this variant. Conclusion We are the first to report the mutation of the RAP1GDS1 gene as a potential cause of GDD and hypotonia. However, further investigations into the molecular mechanisms involved are required to confirm the role of RAP1GDS1 gene in causing GDD and hypotonia.
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Affiliation(s)
- Abdulaziz Asiri
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Essra Aloyouni
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Muhammad Umair
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Yusra Alyafee
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Abeer Al Tuwaijri
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Kheloud M Alhamoudi
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Bader Almuzzaini
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Abeer Al Baz
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Deemah Alwadaani
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Marwan Nashabat
- Division of Genetics, Department of Pediatrics, King Abdullah Specialized Children's Hospital, King Saud Bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Majid Alfadhel
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia.,Division of Genetics, Department of Pediatrics, King Abdullah Specialized Children's Hospital, King Saud Bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Riyadh, Saudi Arabia
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18
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Kotelevets L, Chastre E. Rac1 Signaling: From Intestinal Homeostasis to Colorectal Cancer Metastasis. Cancers (Basel) 2020; 12:cancers12030665. [PMID: 32178475 PMCID: PMC7140047 DOI: 10.3390/cancers12030665] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/06/2020] [Accepted: 03/08/2020] [Indexed: 12/14/2022] Open
Abstract
The small GTPase Rac1 has been implicated in a variety of dynamic cell biological processes, including cell proliferation, cell survival, cell-cell contacts, epithelial mesenchymal transition (EMT), cell motility, and invasiveness. These processes are orchestrated through the fine tuning of Rac1 activity by upstream cell surface receptors and effectors that regulate the cycling Rac1-GDP (off state)/Rac1-GTP (on state), but also through the tuning of Rac1 accumulation, activity, and subcellular localization by post translational modifications or recruitment into molecular scaffolds. Another level of regulation involves Rac1 transcripts stability and splicing. Downstream, Rac1 initiates a series of signaling networks, including regulatory complex of actin cytoskeleton remodeling, activation of protein kinases (PAKs, MAPKs) and transcription factors (NFkB, Wnt/β-catenin/TCF, STAT3, Snail), production of reactive oxygen species (NADPH oxidase holoenzymes, mitochondrial ROS). Thus, this GTPase, its regulators, and effector systems might be involved at different steps of the neoplastic progression from dysplasia to the metastatic cascade. After briefly placing Rac1 and its effector systems in the more general context of intestinal homeostasis and in wound healing after intestinal injury, the present review mainly focuses on the several levels of Rac1 signaling pathway dysregulation in colorectal carcinogenesis, their biological significance, and their clinical impact.
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Affiliation(s)
- Larissa Kotelevets
- Institut National de la Santé et de la Recherche Médicale, UMR S 938, Centre de Recherche Saint-Antoine, 75012 Paris, France
- Sorbonne Université, Hôpital Saint-Antoine, Site Bâtiment Kourilsky, 75012 Paris, France
- Correspondence: (L.K.); (E.C.)
| | - Eric Chastre
- Institut National de la Santé et de la Recherche Médicale, UMR S 938, Centre de Recherche Saint-Antoine, 75012 Paris, France
- Sorbonne Université, Hôpital Saint-Antoine, Site Bâtiment Kourilsky, 75012 Paris, France
- Correspondence: (L.K.); (E.C.)
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19
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P-REX1-Independent, Calcium-Dependent RAC1 Hyperactivation in Prostate Cancer. Cancers (Basel) 2020; 12:cancers12020480. [PMID: 32092966 PMCID: PMC7072377 DOI: 10.3390/cancers12020480] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/07/2020] [Accepted: 02/17/2020] [Indexed: 12/15/2022] Open
Abstract
The GTPase Rac1 is a well-established master regulator of cell motility and invasiveness contributing to cancer metastasis. Dysregulation of the Rac1 signaling pathway, resulting in elevated motile and invasive potential, has been reported in multiple cancers. However, there are limited studies on the regulation of Rac1 in prostate cancer. Here, we demonstrate that aggressive androgen-independent prostate cancer cells display marked hyperactivation of Rac1. This hyperactivation is independent of P-Rex1 activity or its direct activators, the PI3K product PIP3 and Gβγ subunits. Furthermore, we demonstrate that the motility and invasiveness of PC3 prostate cancer cells is independent of P-Rex1, supporting the analysis of publicly available datasets indicating no correlation between high P-Rex1 expression and cancer progression in patients. Rac1 hyperactivation was not related to the presence of activating Rac1 mutations and was insensitive to overexpression of a Rac-GAP or the silencing of specific Rac-GEFs expressed in prostate cancer cells. Interestingly, active Rac1 levels in these cells were markedly reduced by elevations in intracellular calcium or by serum stimulation, suggesting the presence of an alternative means of Rac1 regulation in prostate cancer that does not involve previously established paradigms.
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20
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Splice switching an oncogenic ratio of SmgGDS isoforms as a strategy to diminish malignancy. Proc Natl Acad Sci U S A 2020; 117:3627-3636. [PMID: 32019878 DOI: 10.1073/pnas.1914153117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The chaperone protein SmgGDS promotes cell-cycle progression and tumorigenesis in human breast and nonsmall cell lung cancer. Splice variants of SmgGDS, named SmgGDS-607 and SmgGDS-558, facilitate the activation of oncogenic members of the Ras and Rho families of small GTPases through membrane trafficking via regulation of the prenylation pathway. SmgGDS-607 interacts with newly synthesized preprenylated small GTPases, while SmgGDS-558 interacts with prenylated small GTPases. We determined that cancer cells have a high ratio of SmgGDS-607:SmgGDS-558 (607:558 ratio), and this elevated ratio is associated with reduced survival of breast cancer patients. These discoveries suggest that targeting SmgGDS splicing to lower the 607:558 ratio may be an effective strategy to inhibit the malignant phenotype generated by small GTPases. Here we report the development of a splice-switching oligonucleotide, named SSO Ex5, that lowers the 607:558 ratio by altering exon 5 inclusion in SmgGDS pre-mRNA (messenger RNA). Our results indicate that SSO Ex5 suppresses the prenylation of multiple small GTPases in the Ras, Rho, and Rab families and inhibits ERK activity, resulting in endoplasmic reticulum (ER) stress, the unfolded protein response, and ultimately apoptotic cell death in breast and lung cancer cell lines. Furthermore, intraperitoneal (i.p.) delivery of SSO Ex5 in MMTV-PyMT mice redirects SmgGDS splicing in the mammary gland and slows tumorigenesis in this aggressive model of breast cancer. Taken together, our results suggest that the high 607:558 ratio is required for optimal small GTPase prenylation, and validate this innovative approach of targeting SmgGDS splicing to diminish malignancy in breast and lung cancer.
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21
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Sterk C, Gräber L, Schmitz HP, Heinisch JJ. Analysis of Functional Domains in Rho5, the Yeast Homolog of Human Rac1 GTPase, in Oxidative Stress Response. Int J Mol Sci 2019; 20:ijms20225550. [PMID: 31703278 PMCID: PMC6888954 DOI: 10.3390/ijms20225550] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/03/2019] [Accepted: 11/05/2019] [Indexed: 12/23/2022] Open
Abstract
The small GTPase Rho5 of Saccharomyces cerevisiae is required for proper regulation of different signaling pathways, which includes the response to cell wall, osmotic, nutrient, and oxidative stress. We here show that proper in vivo function and intracellular distribution of Rho5 depends on its hypervariable region at the carboxyterminal end, which includes the CAAX box for lipid modification, a preceding polybasic region (PBR) carrying a serine residue, and a 98 amino acid–specific insertion only present in Rho5 of S. cerevisiae but not in its human homolog Rac1. Results from trapping GFP-Rho5 variants to the mitochondrial surface suggest that the GTPase needs to be activated at the plasma membrane prior to its translocation to mitochondria in order to fulfil its role in oxidative stress response. These findings are supported by heterologous expression of a codon-optimized human RAC1 gene, which can only complement a yeast rho5 deletion in a chimeric fusion with RHO5 sequences that restore the correct spatiotemporal distribution of the encoded protein.
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22
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Nogi M, Satoh K, Sunamura S, Kikuchi N, Satoh T, Kurosawa R, Omura J, Elias-Al-Mamun M, Abdul Hai Siddique M, Numano K, Kudo S, Miyata S, Akiyama M, Kumagai K, Kawamoto S, Saiki Y, Shimokawa H. Small GTP-Binding Protein GDP Dissociation Stimulator Prevents Thoracic Aortic Aneurysm Formation and Rupture by Phenotypic Preservation of Aortic Smooth Muscle Cells. Circulation 2019; 138:2413-2433. [PMID: 29921611 DOI: 10.1161/circulationaha.118.035648] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Thoracic aortic aneurysm (TAA) and dissection are fatal diseases that cause aortic rupture and sudden death. The small GTP-binding protein GDP dissociation stimulator (SmgGDS) is a crucial mediator of the pleiotropic effects of statins. Previous studies revealed that reduced force generation in aortic smooth muscle cells (AoSMCs) causes TAA and thoracic aortic dissection. METHODS To examine the role of SmgGDS in TAA formation, we used an angiotensin II (1000 ng·min-1·kg-1, 4 weeks)-induced TAA model. RESULTS We found that 33% of Apoe-/- SmgGDS+/- mice died suddenly as a result of TAA rupture, whereas there was no TAA rupture in Apoe-/- control mice. In contrast, there was no significant difference in the ratio of abdominal aortic aneurysm rupture between the 2 genotypes. We performed ultrasound imaging every week to follow up the serial changes in aortic diameters. The diameter of the ascending aorta progressively increased in Apoe-/- SmgGDS+/- mice compared with Apoe-/- mice, whereas that of the abdominal aorta remained comparable between the 2 genotypes. Histological analysis of Apoe-/- SmgGDS+/- mice showed dissections of major thoracic aorta in the early phase of angiotensin II infusion (day 3 to 5) and more severe elastin degradation compared with Apoe-/- mice. Mechanistically, Apoe-/- SmgGDS+/- mice showed significantly higher levels of oxidative stress, matrix metalloproteinases, and inflammatory cell migration in the ascending aorta compared with Apoe-/- mice. For mechanistic analyses, we primary cultured AoSMCs from the 2 genotypes. After angiotensin II (100 nmol/L) treatment for 24 hours, Apoe-/- SmgGDS+/- AoSMCs showed significantly increased matrix metalloproteinase activity and oxidative stress levels compared with Apoe-/- AoSMCs. In addition, SmgGDS deficiency increased cytokines/chemokines and growth factors in AoSMCs. Moreover, expressions of fibrillin-1 ( FBN1), α-smooth muscle actin ( ACTA2), myosin-11 ( MYH11), MYLLK, and PRKG1, which are force generation genes, were significantly reduced in Apoe-/- SmgGDS+/- AoSMCs compared with Apoe-/- AoSMCs. A similar tendency was noted in AoSMCs from patients with TAA compared with those from control subjects. Finally, local delivery of the SmgGDS gene construct reversed the dilation of the ascending aorta in Apoe-/- SmgGDS+/- mice. CONCLUSIONS These results suggest that SmgGDS is a novel therapeutic target for the prevention and treatment of TAA.
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Affiliation(s)
- Masamichi Nogi
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kimio Satoh
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shinichiro Sunamura
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Nobuhiro Kikuchi
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Taijyu Satoh
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ryo Kurosawa
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Junichi Omura
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Md Elias-Al-Mamun
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Mohammad Abdul Hai Siddique
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kazuhiko Numano
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shun Kudo
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Satoshi Miyata
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Masatoshi Akiyama
- Cardiovascular Surgery (M.A., K.K., S. Kawamoto, Y.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kiichiro Kumagai
- Cardiovascular Surgery (M.A., K.K., S. Kawamoto, Y.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shunsuke Kawamoto
- Cardiovascular Surgery (M.A., K.K., S. Kawamoto, Y.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yoshikatsu Saiki
- Cardiovascular Surgery (M.A., K.K., S. Kawamoto, Y.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroaki Shimokawa
- Departments of Cardiovascular Medicine (M.N., K.S., S.S., N.K., T.S., R.K., J.O., M.E.-A.-M., M.A.H.S., K.N., S. Kudo, S.M., H.S.), Tohoku University Graduate School of Medicine, Sendai, Japan
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23
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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: 33] [Impact Index Per Article: 6.6] [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.
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24
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Nissim S, Leshchiner I, Mancias JD, Greenblatt MB, Maertens O, Cassa CA, Rosenfeld JA, Cox AG, Hedgepeth J, Wucherpfennig JI, Kim AJ, Henderson JE, Gonyo P, Brandt A, Lorimer E, Unger B, Prokop JW, Heidel JR, Wang XX, Ukaegbu CI, Jennings BC, Paulo JA, Gableske S, Fierke CA, Getz G, Sunyaev SR, Wade Harper J, Cichowski K, Kimmelman AC, Houvras Y, Syngal S, Williams C, Goessling W. Mutations in RABL3 alter KRAS prenylation and are associated with hereditary pancreatic cancer. Nat Genet 2019; 51:1308-1314. [PMID: 31406347 DOI: 10.1038/s41588-019-0475-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 07/01/2019] [Indexed: 12/16/2022]
Abstract
Pancreatic ductal adenocarcinoma is an aggressive cancer with limited treatment options1. Approximately 10% of cases exhibit familial predisposition, but causative genes are not known in most families2. We perform whole-genome sequence analysis in a family with multiple cases of pancreatic ductal adenocarcinoma and identify a germline truncating mutation in the member of the RAS oncogene family-like 3 (RABL3) gene. Heterozygous rabl3 mutant zebrafish show increased susceptibility to cancer formation. Transcriptomic and mass spectrometry approaches implicate RABL3 in RAS pathway regulation and identify an interaction with RAP1GDS1 (SmgGDS), a chaperone regulating prenylation of RAS GTPases3. Indeed, the truncated mutant RABL3 protein accelerates KRAS prenylation and requires RAS proteins to promote cell proliferation. Finally, evidence in patient cohorts with developmental disorders implicates germline RABL3 mutations in RASopathy syndromes. Our studies identify RABL3 mutations as a target for genetic testing in cancer families and uncover a mechanism for dysregulated RAS activity in development and cancer.
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Affiliation(s)
- Sahar Nissim
- Gastroenterology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Dana-Farber Cancer Institute, Boston, MA, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Ignaty Leshchiner
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,The Eli and Edythe L. Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Joseph D Mancias
- Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Matthew B Greenblatt
- Department of Pathology and Laboratory Medicine and the Hospital for Special Surgery, Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Ophélia Maertens
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christopher A Cassa
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jill A Rosenfeld
- The Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Andrew G Cox
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia
| | - John Hedgepeth
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Julia I Wucherpfennig
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Andrew J Kim
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jake E Henderson
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Patrick Gonyo
- Cancer Center and Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Anthony Brandt
- Cancer Center and Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ellen Lorimer
- Cancer Center and Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Bethany Unger
- Cancer Center and Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jeremy W Prokop
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Jerry R Heidel
- Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | | | | | | | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | | | - Carol A Fierke
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Gad Getz
- The Eli and Edythe L. Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Cancer Center and Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Shamil R Sunyaev
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Karen Cichowski
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Dana-Farber Cancer Institute, Boston, MA, USA
| | - Alec C Kimmelman
- Department of Radiation Oncology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, USA
| | - Yariv Houvras
- Weill Cornell Medical College and New York Presbyterian Hospital, New York, NY, USA
| | - Sapna Syngal
- Gastroenterology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Dana-Farber Cancer Institute, Boston, MA, USA
| | - Carol Williams
- Cancer Center and Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Wolfram Goessling
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. .,Dana-Farber Cancer Institute, Boston, MA, USA. .,Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA. .,The Eli and Edythe L. Broad Institute of MIT and Harvard, Cambridge, MA, USA. .,Harvard Stem Cell Institute, Cambridge, MA, USA. .,Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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25
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García-Torres D, Fierke CA. The chaperone SmgGDS-607 has a dual role, both activating and inhibiting farnesylation of small GTPases. J Biol Chem 2019; 294:11793-11804. [PMID: 31197034 DOI: 10.1074/jbc.ra119.007438] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 06/12/2019] [Indexed: 11/06/2022] Open
Abstract
Ras family small GTPases undergo prenylation (such as farnesylation) for proper localization to the plasma membrane, where they can initiate oncogenic signaling pathways. Small GTP-binding protein GDP-dissociation stimulator (SmgGDS) proteins are chaperones that bind and traffic small GTPases, although their exact cellular function is unknown. Initially, SmgGDS proteins were classified as guanine nucleotide exchange factors, but recent findings suggest that SmgGDS proteins also regulate prenylation of small GTPases in vivo in a substrate-selective manner. SmgGDS-607 recognizes the polybasic region and the CAAX box of several small GTPases and inhibits prenylation by impeding their entry into the geranylgeranylation pathway. Here, using recombinant and purified enzymes for prenylation and protein-binding assays, we demonstrate that SmgGDS-607 differentially regulates farnesylation of several small GTPases. SmgGDS-607 inhibited farnesylation of some proteins, such as DiRas1, by sequestering the protein and limiting modification catalyzed by protein farnesyltransferase (FTase). We found that the competitive binding affinities of the small GTPase for SmgGDS-607 and FTase dictate the extent of this inhibition. Additionally, we discovered that SmgGDS-607 increases the rate of farnesylation of HRas by enhancing product release from FTase. Our work indicates that SmgGDS-607 binds to a broad range of small GTPases and does not require a PBR for recognition. Together, these results provide mechanistic insight into SmgGDS-607-mediated regulation of farnesylation of small GTPases and suggest that SmgGDS-607 has multiple modes of substrate recognition.
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Affiliation(s)
| | - Carol A Fierke
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109
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26
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Abdrabou A, Wang Z. Post-Translational Modification and Subcellular Distribution of Rac1: An Update. Cells 2018; 7:cells7120263. [PMID: 30544910 PMCID: PMC6316090 DOI: 10.3390/cells7120263] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/06/2018] [Accepted: 12/10/2018] [Indexed: 12/27/2022] Open
Abstract
Rac1 is a small GTPase that belongs to the Rho family. The Rho family of small GTPases is a subfamily of the Ras superfamily. The Rho family of GTPases mediate a plethora of cellular effects, including regulation of cytoarchitecture, cell size, cell adhesion, cell polarity, cell motility, proliferation, apoptosis/survival, and membrane trafficking. The cycling of Rac1 between the GTP (guanosine triphosphate)- and GDP (guanosine diphosphate)-bound states is essential for effective signal flow to elicit downstream biological functions. The cycle between inactive and active forms is controlled by three classes of regulatory proteins: Guanine nucleotide exchange factors (GEFs), GTPase-activating proteins (GAPs), and guanine-nucleotide-dissociation inhibitors (GDIs). Other modifications include RNA splicing and microRNAs; various post-translational modifications have also been shown to regulate the activity and function of Rac1. The reported post-translational modifications include lipidation, ubiquitination, phosphorylation, and adenylylation, which have all been shown to play important roles in the regulation of Rac1 and other Rho GTPases. Moreover, the Rac1 activity and function are regulated by its subcellular distribution and translocation. This review focused on the most recent progress in Rac1 research, especially in the area of post-translational modification and subcellular distribution and translocation.
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Affiliation(s)
- Abdalla Abdrabou
- Department of Medical Genetics, and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| | - Zhixiang Wang
- Department of Medical Genetics, and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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27
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Ahearn I, Zhou M, Philips MR. Posttranslational Modifications of RAS Proteins. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a031484. [PMID: 29311131 DOI: 10.1101/cshperspect.a031484] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The three human RAS genes encode four proteins that play central roles in oncogenesis by acting as binary molecular switches that regulate signaling pathways for growth and differentiation. Each is subject to a set of posttranslational modifications (PTMs) that modify their activity or are required for membrane targeting. The enzymes that catalyze the various PTMs are potential targets for anti-RAS drug discovery. The PTMs of RAS proteins are the focus of this review.
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Affiliation(s)
- Ian Ahearn
- Department of Medicine, Perlmutter Cancer Center, New York University School of Medicine, New York, New York 10016
| | - Mo Zhou
- Department of Medicine, Perlmutter Cancer Center, New York University School of Medicine, New York, New York 10016
| | - Mark R Philips
- Department of Medicine, Perlmutter Cancer Center, New York University School of Medicine, New York, New York 10016
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28
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The Many Faces of Rap1 GTPase. Int J Mol Sci 2018; 19:ijms19102848. [PMID: 30241315 PMCID: PMC6212855 DOI: 10.3390/ijms19102848] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 09/16/2018] [Accepted: 09/17/2018] [Indexed: 12/12/2022] Open
Abstract
This review addresses the issue of the numerous roles played by Rap1 GTPase (guanosine triphosphatase) in different cell types, in terms of both physiology and pathology. It is one among a myriad of small G proteins with endogenous GTP-hydrolyzing activity that is considerably stimulated by posttranslational modifications (geranylgeranylation) or guanine nucleotide exchange factors (GEFs), and inhibited by GTPase-activating proteins (GAPs). Rap1 is a ubiquitous protein that plays an essential role in the control of metabolic processes, such as signal transduction from plasma membrane receptors, cytoskeleton rearrangements necessary for cell division, intracellular and substratum adhesion, as well as cell motility, which is needed for extravasation or fusion. We present several examples of how Rap1 affects cells and organs, pointing to possible molecular manipulations that could have application in the therapy of several diseases.
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29
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GEF mechanism revealed by the structure of SmgGDS-558 and farnesylated RhoA complex and its implication for a chaperone mechanism. Proc Natl Acad Sci U S A 2018; 115:9563-9568. [PMID: 30190425 DOI: 10.1073/pnas.1804740115] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
SmgGDS has dual functions in cells and regulates small GTPases as both a guanine nucleotide exchange factor (GEF) for the Rho family and a molecular chaperone for small GTPases possessing a C-terminal polybasic region followed by four C-terminal residues called the CaaX motif, which is posttranslationally prenylated at its cysteine residue. Our recent structural work revealed that SmgGDS folds into tandem copies of armadillo-repeat motifs (ARMs) that are not present in other GEFs. However, the precise mechanism of GEF activity and recognition mechanism for the prenylated CaaX motif remain unknown because SmgGDS does not have a typical GEF catalytic domain and lacks a pocket to accommodate a prenyl group. Here, we aimed to determine the crystal structure of the SmgGDS/farnesylated RhoA complex. We found that SmgGDS induces a significant conformational change in the switch I and II regions that opens up the nucleotide-binding site, with the prenyl group fitting into the cryptic pocket in the N-terminal ARMs. Taken together, our findings could advance the understanding of the role of SmgGDS and enable drug design strategies for targeting SmgGDS and small GTPases.
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30
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Jennings BC, Lawton AJ, Rizk Z, Fierke CA. SmgGDS-607 Regulation of RhoA GTPase Prenylation Is Nucleotide-Dependent. Biochemistry 2018; 57:4289-4298. [PMID: 29940100 DOI: 10.1021/acs.biochem.8b00567] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Protein prenylation involves the attachment of a hydrophobic isoprenoid moiety to the C-terminus of proteins. Several small GTPases, including members of the Ras and Rho subfamilies, require prenylation for their normal and pathological functions. Recent work has suggested that SmgGDS proteins regulate the prenylation of small GTPases in vivo. Using RhoA as a representative small GTPase, we directly test this hypothesis using biochemical assays and present a mechanism describing the mode of prenylation regulation. SmgGDS-607 completely inhibits RhoA prenylation catalyzed by protein geranylgeranyltransferase I (GGTase-I) in an in vitro radiolabel incorporation assay. SmgGDS-607 inhibits prenylation by binding to and blocking access to the C-terminal tail of the small GTPase (substrate sequestration mechanism) rather than via inhibition of the prenyltransferase activity. The reactivity of GGTase-I with RhoA is unaffected by addition of nucleotides. In contrast, the affinity of SmgGDS-607 for RhoA varies with the nucleotide bound to RhoA; SmgGDS-607 has a higher affinity for RhoA-GDP compared to RhoA-GTP. Consequently, the prenylation blocking function of SmgGDS-607 is regulated by the bound nucleotide. This work provides mechanistic insight into a novel pathway for the regulation of small GTPase protein prenylation by SmgGDS-607 and demonstrates that peptides are a good mimic for full-length proteins when measuring GGTase-I activity.
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Affiliation(s)
- Benjamin C Jennings
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Alexis J Lawton
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Zeinab Rizk
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Carol A Fierke
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
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31
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Zhang X, Cao S, Barila G, Edreira MM, Hong K, Wankhede M, Naim N, Buck M, Altschuler DL. Cyclase-associated protein 1 (CAP1) is a prenyl-binding partner of Rap1 GTPase. J Biol Chem 2018; 293:7659-7673. [PMID: 29618512 PMCID: PMC5961064 DOI: 10.1074/jbc.ra118.001779] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 02/22/2018] [Indexed: 12/20/2022] Open
Abstract
Rap1 proteins are members of the Ras subfamily of small GTPases involved in many biological responses, including adhesion, cell proliferation, and differentiation. Like all small GTPases, they work as molecular allosteric units that are active in signaling only when associated with the proper membrane compartment. Prenylation, occurring in the cytosol, is an enzymatic posttranslational event that anchors small GTPases at the membrane, and prenyl-binding proteins are needed to mask the cytoplasm-exposed lipid during transit to the target membrane. However, several of these proteins still await discovery. In this study, we report that cyclase-associated protein 1 (CAP1) binds Rap1. We found that this binding is GTP-independent, does not involve Rap1's effector domain, and is fully contained in its C-terminal hypervariable region (HVR). Furthermore, Rap1 prenylation was required for high-affinity interactions with CAP1 in a geranylgeranyl-specific manner. The prenyl binding specifically involved CAP1's C-terminal hydrophobic β-sheet domain. We present a combination of experimental and computational approaches, yielding a model whereby the high-affinity binding between Rap1 and CAP1 involves electrostatic and nonpolar side-chain interactions between Rap1's HVR residues, lipid, and CAP1 β-sheet domain. The binding was stabilized by the lipid insertion into the β-solenoid whose interior was occupied by nonpolar side chains. This model was reminiscent of the recently solved structure of the PDEδ-K-Ras complex; accordingly, disruptors of this complex, e.g. deltarasin, blocked the Rap1-CAP1 interaction. These findings indicate that CAP1 is a geranylgeranyl-binding partner of Rap1.
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Affiliation(s)
- Xuefeng Zhang
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 and
| | - Shufen Cao
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44116
| | - Guillermo Barila
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 and
| | - Martin M Edreira
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 and
| | - Kyoungja Hong
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 and
| | - Mamta Wankhede
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 and
| | - Nyla Naim
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 and
| | - Matthias Buck
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44116
| | - Daniel L Altschuler
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 and
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32
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Jiang H, Zhang X, Chen X, Aramsangtienchai P, Tong Z, Lin H. Protein Lipidation: Occurrence, Mechanisms, Biological Functions, and Enabling Technologies. Chem Rev 2018; 118:919-988. [PMID: 29292991 DOI: 10.1021/acs.chemrev.6b00750] [Citation(s) in RCA: 286] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Protein lipidation, including cysteine prenylation, N-terminal glycine myristoylation, cysteine palmitoylation, and serine and lysine fatty acylation, occurs in many proteins in eukaryotic cells and regulates numerous biological pathways, such as membrane trafficking, protein secretion, signal transduction, and apoptosis. We provide a comprehensive review of protein lipidation, including descriptions of proteins known to be modified and the functions of the modifications, the enzymes that control them, and the tools and technologies developed to study them. We also highlight key questions about protein lipidation that remain to be answered, the challenges associated with answering such questions, and possible solutions to overcome these challenges.
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Affiliation(s)
- Hong Jiang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiaoyu Zhang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiao Chen
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Pornpun Aramsangtienchai
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Zhen Tong
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
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33
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Lau HY, Wang M. Small change, big effect: Taking RAS by the tail through suppression of post-prenylation carboxylmethylation. Small GTPases 2017; 11:271-279. [PMID: 29261009 DOI: 10.1080/21541248.2017.1415637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mutant RAS isoforms are the most common oncogenes affecting human cancers. After decades of effort in developing drugs targeting oncogenic RAS-driven cancers, we are still charting an unclear path. Despite recent developments exemplified by KRAS (G12C) inhibitors, direct targeting of mutant RAS remains a difficult endeavor. Inhibiting RAS function by targeting its post-translational prenylation processing has remained an important approach, especially with recent progress on the study of isoprenylcysteine carboxylmethyltransferase (ICMT), the unique enzyme for the last step of prenylation processing of RAS isoforms and other substrates. Inhibition of ICMT has shown efficacy both in vitro and in vivo in RAS-mutant cancer models. We will discuss the roles of RAS family of proteins in human cancers and the impact of post-prenylation carboxylmethylation on RAS driven tumorigenesis. In addition, we will review what is known of the molecular and cellular impact of ICMT inhibition on cancer cells that underlie its anti-proliferative and pro-apoptosis efficacy.
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Affiliation(s)
- Hiu Yeung Lau
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School , Singapore
| | - Mei Wang
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School , Singapore.,Department of Biochemistry, National University of Singapore , Singapore
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34
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Wang S, Yin Z, Zhao B, Qi Y, Liu J, Rahimi SA, Lee LY, Li S. Microgravity simulation activates Cdc42 via Rap1GDS1 to promote vascular branch morphogenesis during vasculogenesis. Stem Cell Res 2017; 25:157-165. [PMID: 29145128 DOI: 10.1016/j.scr.2017.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/15/2017] [Accepted: 11/03/2017] [Indexed: 12/12/2022] Open
Abstract
Gravity plays an important role in normal tissue maintenance. The ability of stem cells to repair tissue loss in space through regeneration and differentiation remains largely unknown. To investigate the impact of microgravity on blood vessel formation from pluripotent stem cells, we employed the embryoid body (EB) model for vasculogenesis and simulated microgravity by clinorotation. We first differentiated mouse embryonic stem cells into cystic EBs containing two germ layers and then analyzed vessel formation under clinorotation. We observed that endothelial cell differentiation was slightly reduced under clinorotation, whereas vascular branch morphogenesis was markedly enhanced. EB-derived endothelial cells migrated faster, displayed multiple cellular processes, and had higher Cdc42 and Rac1 activity when subjected to clinorotation. Genetic analysis and rescue experiments demonstrated that Cdc42 but not Rac1 is required for microgravity-induced vascular branch morphogenesis. Furthermore, affinity pull-down assay and mass spectrometry identified Rap1GDS1 to be a Cdc42 guanine nucleotide exchange factor, which was upregulated by clinorotation. shRNA-mediated knockdown of Rap1GDS1 selectively suppressed Cdc42 activation and inhibited both baseline and microgravity-induced vasculogenesis. This was rescued by ectopic expression of constitutively active Cdc42. Taken together, these results support the notion that simulated microgravity activates Cdc42 via Rap1GDS1 to promote vascular branch morphogenesis.
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Affiliation(s)
- Shouli Wang
- Department of Cardiology, Beijing 306 Hospital, Beijing 100101, China.
| | - Zhao Yin
- Department of Cardiology, Beijing 306 Hospital, Beijing 100101, China
| | - Bei Zhao
- Department of Cardiology, Beijing 306 Hospital, Beijing 100101, China
| | - Yanmei Qi
- Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08903, USA
| | - Jie Liu
- Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08903, USA
| | - Saum A Rahimi
- Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08903, USA
| | - Leonard Y Lee
- Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08903, USA
| | - Shaohua Li
- Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08903, USA.
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35
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Kargapolova Y, Levin M, Lackner K, Danckwardt S. sCLIP-an integrated platform to study RNA-protein interactomes in biomedical research: identification of CSTF2tau in alternative processing of small nuclear RNAs. Nucleic Acids Res 2017; 45:6074-6086. [PMID: 28334977 PMCID: PMC5449641 DOI: 10.1093/nar/gkx152] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 02/23/2017] [Indexed: 11/13/2022] Open
Abstract
RNA-binding proteins (RBPs) are central for gene expression by controlling the RNA fate from birth to decay. Various disorders arising from perturbations of RNA-protein interactions document their critical function. However, deciphering their function is complex, limiting the general functional elucidation of this growing class of proteins and their contribution to (patho)physiology. Here, we present sCLIP, a simplified and robust platform for genome-wide interrogation of RNA-protein interactomes based on crosslinking-immunoprecipitation and high-throughput sequencing. sCLIP exploits linear amplification of the immunoprecipitated RNA improving the complexity of the sequencing-library despite significantly reducing the amount of input material and omitting several purification steps. Additionally, it permits a radiolabel-free visualization of immunoprecipitated RNA. In a proof of concept, we identify that CSTF2tau binds many previously not recognized RNAs including histone, snoRNA and snRNAs. CSTF2tau-binding is associated with internal oligoadenylation resulting in shortened snRNA isoforms subjected to rapid degradation. We provide evidence for a new mechanism whereby CSTF2tau controls the abundance of snRNAs resulting in alternative splicing of several RNAs including ANK2 with critical roles in tumorigenesis and cardiac function. Combined with a bioinformatic pipeline sCLIP thus uncovers new functions for established RBPs and fosters the illumination of RBP-protein interaction landscapes in health and disease.
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Affiliation(s)
- Yulia Kargapolova
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Germany.,Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Germany
| | - Michal Levin
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Germany.,Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Germany
| | - Karl Lackner
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Germany.,German Center for Cardiovascular Research (DZHK), Germany
| | - Sven Danckwardt
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Germany.,Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Germany.,German Center for Cardiovascular Research (DZHK), Germany
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36
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Gonyo P, Bergom C, Brandt AC, Tsaih SW, Sun Y, Bigley TM, Lorimer EL, Terhune SS, Rui H, Flister MJ, Long RM, Williams CL. SmgGDS is a transient nucleolar protein that protects cells from nucleolar stress and promotes the cell cycle by regulating DREAM complex gene expression. Oncogene 2017; 36:6873-6883. [PMID: 28806394 PMCID: PMC5730474 DOI: 10.1038/onc.2017.280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/07/2017] [Accepted: 07/03/2017] [Indexed: 12/19/2022]
Abstract
The chaperone protein and guanine nucleotide exchange factor SmgGDS (RAP1GDS1) is a key promoter of cancer cell proliferation and tumorigenesis. SmgGDS undergoes nucleocytoplasmic shuttling, suggesting that it has both cytoplasmic and nuclear functions that promote cancer. Previous studies indicate that SmgGDS binds cytoplasmic small GTPases and promotes their trafficking to the plasma membrane. In contrast, little is known about the functions of SmgGDS in the nucleus, or how these nuclear functions might benefit cancer cells. Here we show unique nuclear localization and regulation of gene transcription pathways by SmgGDS. Strikingly, SmgGDS depletion significantly reduces expression of over 600 gene products that are targets of the DREAM complex, which is a transcription factor complex that regulates expression of proteins controlling the cell cycle. The cell cycle regulators E2F1, MYC, MYBL2 (B-Myb) and FOXM1 are among the DREAM targets that are diminished by SmgGDS depletion. E2F1 is well known to promote G1 cell cycle progression, and the loss of E2F1 in SmgGDS-depleted cells provides an explanation for previous reports that SmgGDS depletion characteristically causes a G1 cell cycle arrest. We show that SmgGDS localizes in nucleoli, and that RNAi-mediated depletion of SmgGDS in cancer cells disrupts nucleolar morphology, signifying nucleolar stress. We show that nucleolar SmgGDS interacts with the RNA polymerase I transcription factor upstream binding factor (UBF). The RNAi-mediated depletion of UBF diminishes nucleolar localization of SmgGDS and promotes proteasome-mediated degradation of SmgGDS, indicating that nucleolar sequestration of SmgGDS by UBF stabilizes SmgGDS protein. The ability of SmgGDS to interact with UBF and localize in the nucleolus is diminished by expressing DiRas1 or DiRas2, which are small GTPases that bind SmgGDS and act as tumor suppressors. Taken together, our results support a novel nuclear role for SmgGDS in protecting malignant cells from nucleolar stress, thus promoting cell cycle progression and tumorigenesis.
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Affiliation(s)
- P Gonyo
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - C Bergom
- Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - A C Brandt
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - S-W Tsaih
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Y Sun
- Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - T M Bigley
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pediatrics, Washington University in St Louis, St Louis, MO, USA
| | - E L Lorimer
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - S S Terhune
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA.,Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - H Rui
- Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - M J Flister
- Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - R M Long
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA.,Medical College of Wisconsin Central Wisconsin Campus, Wausau, WI, USA
| | - C L Williams
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
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37
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Shimizu H, Toma-Fukai S, Saijo S, Shimizu N, Kontani K, Katada T, Shimizu T. Structure-based analysis of the guanine nucleotide exchange factor SmgGDS reveals armadillo-repeat motifs and key regions for activity and GTPase binding. J Biol Chem 2017; 292:13441-13448. [PMID: 28630045 PMCID: PMC5555202 DOI: 10.1074/jbc.m117.792556] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/14/2017] [Indexed: 01/15/2023] Open
Abstract
Small GTPases are molecular switches that have critical biological roles and are controlled by GTPase-activating proteins and guanine nucleotide exchange factors (GEFs). The smg GDP dissociation stimulator (SmgGDS) protein functions as a GEF for the RhoA and RhoC small GTPases. SmgGDS has various regulatory roles, including small GTPase trafficking and localization and as a molecular chaperone, and interacts with many small GTPases possessing polybasic regions. Two SmgGDS splice variants, SmgGDS-558 and SmgGDS-607, differ in GEF activity and binding affinity for RhoA depending on the lipidation state, but the reasons for these differences are unclear. Here we determined the crystal structure of SmgGDS-558, revealing a fold containing tandem copies of armadillo repeats not present in other GEFs. We also observed that SmgGDS harbors distinct positively and negatively charged regions, both of which play critical roles in binding to RhoA and GEF activity. This is the first report demonstrating a relationship between the molecular function and atomic structure of SmgGDS. Our findings indicate that the two SmgGDS isoforms differ in GTPase binding and GEF activity, depending on the lipidation state, thus providing useful information about the cellular functions of SmgGDS in cells.
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Affiliation(s)
- Hikaru Shimizu
- From the Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Sachiko Toma-Fukai
- From the Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shinya Saijo
- the Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan, and
| | - Nobutaka Shimizu
- the Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan, and
| | - Kenji Kontani
- the Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose-shi, Tokyo 204-8588, Japan
| | - Toshiaki Katada
- From the Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiyuki Shimizu
- From the Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan,
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38
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Chen JJ, Boehning D. Protein Lipidation As a Regulator of Apoptotic Calcium Release: Relevance to Cancer. Front Oncol 2017; 7:138. [PMID: 28706877 PMCID: PMC5489567 DOI: 10.3389/fonc.2017.00138] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 06/16/2017] [Indexed: 12/16/2022] Open
Abstract
Calcium is a critical regulator of cell death pathways. One of the most proximal events leading to cell death is activation of plasma membrane and endoplasmic reticulum-resident calcium channels. A large body of evidence indicates that defects in this pathway contribute to cancer development. Although we have a thorough understanding of how downstream elevations in cytosolic and mitochondrial calcium contribute to cell death, it is much less clear how calcium channels are activated upstream of the apoptotic stimulus. Recently, it has been shown that protein lipidation is a potent regulator of apoptotic signaling. Although classically thought of as a static modification, rapid and reversible protein acylation has emerged as a new signaling paradigm relevant to many pathways, including calcium release and cell death. In this review, we will discuss the role of protein lipidation in regulating apoptotic calcium signaling with direct therapeutic relevance to cancer.
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Affiliation(s)
- Jessica J Chen
- Department of Biochemistry and Molecular Biology, McGovern Medical School, UTHealth, Houston, TX, United States
| | - Darren Boehning
- Department of Biochemistry and Molecular Biology, McGovern Medical School, UTHealth, Houston, TX, United States
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39
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Shah B, Püschel AW. Regulation of Rap GTPases in mammalian neurons. Biol Chem 2017; 397:1055-69. [PMID: 27186679 DOI: 10.1515/hsz-2016-0165] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 05/06/2016] [Indexed: 12/15/2022]
Abstract
Small GTPases are central regulators of many cellular processes. The highly conserved Rap GTPases perform essential functions in the mammalian nervous system during development and in mature neurons. During neocortical development, Rap1 is required to regulate cadherin- and integrin-mediated adhesion. In the adult nervous system Rap1 and Rap2 regulate the maturation and plasticity of dendritic spine and synapses. Although genetic studies have revealed important roles of Rap GTPases in neurons, their regulation by guanine nucleotide exchange factors (GEFs) that activate them and GTPase activating proteins (GAPs) that inactivate them by stimulating their intrinsic GTPase activity is just beginning to be explored in vivo. Here we review how GEFs and GAPs regulate Rap GTPases in the nervous system with a focus on their in vivo function.
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40
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Wilson JM, Prokop JW, Lorimer E, Ntantie E, Williams CL. Differences in the Phosphorylation-Dependent Regulation of Prenylation of Rap1A and Rap1B. J Mol Biol 2016; 428:4929-4945. [PMID: 27760305 DOI: 10.1016/j.jmb.2016.10.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 09/24/2016] [Accepted: 10/10/2016] [Indexed: 12/20/2022]
Abstract
Two isoforms of the small GTPase Rap1, Rap1A and Rap1B, participate in cell adhesion; Rap1A promotes steady state adhesion, while Rap1B regulates dynamic changes in cell adhesion. These events depend on the prenylation of Rap1, which promotes its membrane localization. Here, we identify previously unsuspected differences in the regulation of prenylation of Rap1A versus Rap1B, due in part to their different phosphorylation-dependent interactions with the chaperone protein SmgGDS-607. Previous studies indicate that the activation of Gαs protein-coupled receptors (GPCRs) phosphorylates S-179 and S-180 in the polybasic region (PBR) of Rap1B, which inhibits Rap1B binding to SmgGDS-607 and diminishes Rap1B prenylation and membrane localization. In this study, we investigate how phosphorylation in the PBR of multiple small GTPases, including K-Ras4B, RhoA, Rap1A, and Rap1B, affects their binding to SmgGDS, with emphasis on differences between Rap1A and Rap1B. We identify the amino acids in SmgGDS-607 necessary for binding of Rap1A and Rap1B, and present homology models examining the binding between Rap1A or Rap1B and SmgGDS-607. Unlike Rap1B, phosphorylation in the PBR of Rap1A does not detectably inhibit its prenylation or its binding to SmgGDS-607. Activation of GPCRs suppresses Rap1A prenylation, but unlike this effect on Rap1B, the GPCR-mediated suppression of Rap1A prenylation can occur independently of Rap1A phosphorylation and does not detectably diminish Rap1A membrane localization. These data demonstrate unexpected evolutionarily conserved differences in the ability of GPCRs to regulate the prenylation of Rap1B compared to Rap1A.
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Affiliation(s)
- Jessica M Wilson
- Department of Pharmacology and Toxicology, Cancer Center and Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Jeremy W Prokop
- HudsonAlpha Institute for Biotechnology, 601 Genome Way NW, Huntsville, AL 35806, USA
| | - Ellen Lorimer
- Department of Pharmacology and Toxicology, Cancer Center and Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Elizabeth Ntantie
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, 1415 South Martin Luther King Jr. Boulevard, Tallahassee, FL 32307, USA
| | - Carol L Williams
- Department of Pharmacology and Toxicology, Cancer Center and Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
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41
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Zhou M, Wiener H, Su W, Zhou Y, Liot C, Ahearn I, Hancock JF, Philips MR. VPS35 binds farnesylated N-Ras in the cytosol to regulate N-Ras trafficking. J Cell Biol 2016; 214:445-58. [PMID: 27502489 PMCID: PMC4987297 DOI: 10.1083/jcb.201604061] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/19/2016] [Indexed: 12/28/2022] Open
Abstract
Ras guanosine triphosphatases (GTPases) regulate signaling pathways only when associated with cellular membranes through their C-terminal prenylated regions. Ras proteins move between membrane compartments in part via diffusion-limited, fluid phase transfer through the cytosol, suggesting that chaperones sequester the polyisoprene lipid from the aqueous environment. In this study, we analyze the nature of the pool of endogenous Ras proteins found in the cytosol. The majority of the pool consists of farnesylated, but not palmitoylated, N-Ras that is associated with a high molecular weight (HMW) complex. Affinity purification and mass spectrographic identification revealed that among the proteins found in the HMW fraction is VPS35, a latent cytosolic component of the retromer coat. VPS35 bound to N-Ras in a farnesyl-dependent, but neither palmitoyl- nor guanosine triphosphate (GTP)-dependent, fashion. Silencing VPS35 increased N-Ras's association with cytoplasmic vesicles, diminished GTP loading of Ras, and inhibited mitogen-activated protein kinase signaling and growth of N-Ras-dependent melanoma cells.
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Affiliation(s)
- Mo Zhou
- Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Heidi Wiener
- Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Wenjuan Su
- Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Caroline Liot
- Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Ian Ahearn
- Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Mark R Philips
- Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
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42
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Abstract
Rho GTPases regulate cytoskeletal and cell adhesion dynamics and thereby coordinate a wide range of cellular processes, including cell migration, cell polarity and cell cycle progression. Most Rho GTPases cycle between a GTP-bound active conformation and a GDP-bound inactive conformation to regulate their ability to activate effector proteins and to elicit cellular responses. However, it has become apparent that Rho GTPases are regulated by post-translational modifications and the formation of specific protein complexes, in addition to GTP-GDP cycling. The canonical regulators of Rho GTPases - guanine nucleotide exchange factors, GTPase-activating proteins and guanine nucleotide dissociation inhibitors - are regulated similarly, creating a complex network of interactions to determine the precise spatiotemporal activation of Rho GTPases.
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Affiliation(s)
- Richard G Hodge
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Anne J Ridley
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
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43
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Tsetsos F, Padmanabhuni SS, Alexander J, Karagiannidis I, Tsifintaris M, Topaloudi A, Mantzaris D, Georgitsi M, Drineas P, Paschou P. Meta-Analysis of Tourette Syndrome and Attention Deficit Hyperactivity Disorder Provides Support for a Shared Genetic Basis. Front Neurosci 2016; 10:340. [PMID: 27499730 PMCID: PMC4956656 DOI: 10.3389/fnins.2016.00340] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/06/2016] [Indexed: 12/21/2022] Open
Abstract
Gilles de la Tourette Sydrome (TS) is a childhood onset neurodevelopmental disorder, characterized phenotypically by the presence of multiple motor and vocal tics. It is often accompanied by multiple psychiatric comorbidities, with Attention Deficit/Hyperactivity Disorder (ADHD) among the most common. The extensive co-occurrence of the two disorders suggests a shared genetic background. A major step toward the elucidation of the genetic architecture of TS was undertaken by the first TS Genome-wide Association Study (GWAS) reporting 552 SNPs that were moderately associated with TS (p < 1E-3). Similarly, initial ADHD GWAS attempts and meta-analysis were not able to produce genome-wide significant findings, but have provided insight to the genetic basis of the disorder. Here, we examine the common genetic background of the two neuropsychiatric phenotypes, by meta-analyzing the 552 top hits in the TS GWAS with the results of ADHD first GWASs. We identify 19 significant SNPs, with the top four implicated genes being TBC1D7, GUCY1A3, RAP1GDS1, and CHST11. TBCD17 harbors the top scoring SNP, rs1866863 (p:3.23E-07), located in a regulatory region downstream of the gene, and the third best-scoring SNP, rs2458304 (p:2.54E-06), located within an intron of the gene. Both variants were in linkage disequilibrium with eQTL rs499818, indicating a role in the expression levels of the gene. TBC1D7 is the third subunit of the TSC1/TSC2 complex, an inhibitor of the mTOR signaling pathway, with a central role in cell growth and autophagy. The top genes implicated by our study indicate a complex and intricate interplay between them, warranting further investigation into a possibly shared etiological mechanism for TS and ADHD.
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Affiliation(s)
- Fotis Tsetsos
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
| | - Shanmukha S. Padmanabhuni
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
| | - John Alexander
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
| | - Iordanis Karagiannidis
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
| | - Margaritis Tsifintaris
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
| | - Apostolia Topaloudi
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
| | - Dimitrios Mantzaris
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
| | - Marianthi Georgitsi
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
- Laboratory of General Biology, Department of Medicine, Aristotle University of ThessalonikiThessaloniki, Greece
| | - Petros Drineas
- Computer Science Department, Rensselaer Polytechnic InstituteTroy, NY, USA
| | - Peristera Paschou
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlexandroupolis, Greece
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Patel A, Williams-Perez S, Peyton N, Reicks A, Buzick J, Farley J, Shirar S, Ellerbroek SM. Arg188 drives RhoC membrane binding. Small GTPases 2016; 8:114-121. [PMID: 27355867 DOI: 10.1080/21541248.2016.1205334] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
RhoA and RhoC GTPases are 92% identical but demonstrate unique regulation and function. Phosphorylation of Ser188 has widely been reported to inhibit RhoA activity. RhoC possesses Arg188 in place of Ser188 but retains a canonical upstream PKA recognition sequence. We report here that RhoC-R188S was a PKA substrate in vitro and exhibited less GTP loading compared to wild-type RhoC when expressed in cells. Transiently expressed RhoC was found to be significantly more membrane associated than RhoA. Membrane association of RhoC-R188S and RhoC-R188A were similar to each other and wild-type RhoA, suggesting that Arg188 directly promotes RhoC membrane binding. The positive influence of Arg188 on RhoC membrane association was evident in a constitutively active (Q63L) background. In accordance, RhoA-S188R was significantly more membrane associated than either RhoA or RhoA-S188A. Altogether, these data suggest that swapping residue 188 identity effectively flips the membrane binding profile of wild-type RhoA and RhoC through positive arginine contribution rather than negative phosphoserine regulation.
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Affiliation(s)
- Aditi Patel
- a Department of BCES , Wartburg College , Waverly , IA , USA
| | | | - Nicole Peyton
- a Department of BCES , Wartburg College , Waverly , IA , USA
| | - Amy Reicks
- a Department of BCES , Wartburg College , Waverly , IA , USA
| | - Justin Buzick
- a Department of BCES , Wartburg College , Waverly , IA , USA
| | - Janean Farley
- a Department of BCES , Wartburg College , Waverly , IA , USA
| | - Sarah Shirar
- a Department of BCES , Wartburg College , Waverly , IA , USA
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Bergom C, Hauser AD, Rymaszewski A, Gonyo P, Prokop JW, Jennings BC, Lawton AJ, Frei A, Lorimer EL, Aguilera-Barrantes I, Mackinnon AC, Noon K, Fierke CA, Williams CL. The Tumor-suppressive Small GTPase DiRas1 Binds the Noncanonical Guanine Nucleotide Exchange Factor SmgGDS and Antagonizes SmgGDS Interactions with Oncogenic Small GTPases. J Biol Chem 2016; 291:6534-45. [PMID: 26814130 DOI: 10.1074/jbc.m115.696831] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Indexed: 11/06/2022] Open
Abstract
The small GTPase DiRas1 has tumor-suppressive activities, unlike the oncogenic properties more common to small GTPases such as K-Ras and RhoA. Although DiRas1 has been found to be a tumor suppressor in gliomas and esophageal squamous cell carcinomas, the mechanisms by which it inhibits malignant phenotypes have not been fully determined. In this study, we demonstrate that DiRas1 binds to SmgGDS, a protein that promotes the activation of several oncogenic GTPases. In silico docking studies predict that DiRas1 binds to SmgGDS in a manner similar to other small GTPases. SmgGDS is a guanine nucleotide exchange factor for RhoA, but we report here that SmgGDS does not mediate GDP/GTP exchange on DiRas1. Intriguingly, DiRas1 acts similarly to a dominant-negative small GTPase, binding to SmgGDS and inhibiting SmgGDS binding to other small GTPases, including K-Ras4B, RhoA, and Rap1A. DiRas1 is expressed in normal breast tissue, but its expression is decreased in most breast cancers, similar to its family member DiRas3 (ARHI). DiRas1 inhibits RhoA- and SmgGDS-mediated NF-κB transcriptional activity in HEK293T cells. We also report that DiRas1 suppresses basal NF-κB activation in breast cancer and glioblastoma cell lines. Taken together, our data support a model in which DiRas1 expression inhibits malignant features of cancers in part by nonproductively binding to SmgGDS and inhibiting the binding of other small GTPases to SmgGDS.
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Affiliation(s)
- Carmen Bergom
- From the Cancer Center, the Departments of Radiation Oncology,
| | - Andrew D Hauser
- From the Cancer Center, the Departments of Radiation Oncology, Pharmacology and Toxicology, and the Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, and
| | | | - Patrick Gonyo
- From the Cancer Center, Pharmacology and Toxicology, and
| | | | | | - Alexis J Lawton
- the Department of Chemistry, Biochemistry Undergraduate Program, and
| | - Anne Frei
- From the Cancer Center, the Departments of Radiation Oncology
| | | | | | | | - Kathleen Noon
- the Mass Spectroscopy Facility for Proteomics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Carol A Fierke
- the Department of Chemistry, Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109
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47
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Ogita Y, Egami S, Ebihara A, Ueda N, Katada T, Kontani K. Di-Ras2 Protein Forms a Complex with SmgGDS Protein in Brain Cytosol in Order to Be in a Low Affinity State for Guanine Nucleotides. J Biol Chem 2015; 290:20245-56. [PMID: 26149690 DOI: 10.1074/jbc.m115.637769] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Indexed: 11/06/2022] Open
Abstract
The Ras family of small GTPases function in a wide variety of biological processes as "molecular switches" by cycling between inactive GDP-bound and active GTP-bound forms. Di-Ras1 and Di-Ras2 were originally identified as small GTPases forming a distinct subgroup of the Ras family. Di-Ras1/Di-Ras2 mRNAs are detected predominantly in brain and heart tissues. Biochemical analysis of Di-Ras1/Di-Ras2 has revealed that they have little GTPase activity and that their intrinsic guanine-nucleotide exchange rates are much faster than that of H-Ras. Yet little is known about the biological role(s) of Di-Ras1/Di-Ras2 or of how their activities are regulated. In the present study we found that endogenous Di-Ras2 co-purifies with SmgGDS from rat brain cytosol. Size-exclusion chromatography of purified recombinant proteins showed that Di-Ras2 forms a high affinity complex with SmgGDS. SmgGDS is a guanine nucleotide exchange factor with multiple armadillo repeats and has recently been shown to specifically activate RhoA and RhoC. In contrast to the effect on RhoA, SmgGDS does not act as a guanine nucleotide exchange factor for Di-Ras2 but instead tightly associates with Di-Ras2 to reduce its binding affinity for guanine nucleotides. Finally, pulse-chase analysis revealed that Di-Ras2 binds, in a C-terminal CAAX motif-dependent manner, to SmgGDS immediately after its synthesis. This leads to increased Di-Ras2 stability. We thus propose that isoprenylated Di-Ras2 forms a tight complex with SmgGDS in cytosol immediately after its synthesis, which lowers its affinity for guanine nucleotides.
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Affiliation(s)
- Yoshitaka Ogita
- From the Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Sachiko Egami
- From the Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Arisa Ebihara
- From the Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Nami Ueda
- From the Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Toshiaki Katada
- From the Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Kenji Kontani
- From the Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
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48
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Azoulay-Alfaguter I, Strazza M, Mor A. Chaperone-mediated specificity in Ras and Rap signaling. Crit Rev Biochem Mol Biol 2014; 50:194-202. [PMID: 25488471 DOI: 10.3109/10409238.2014.989308] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ras and Rap proteins are closely related small guanosine triphosphatase (GTPases) that share similar effector-binding domains but operate in a very different signaling networks; Ras has a dominant role in cell proliferation, while Rap mediates cell adhesion. Ras and Rap proteins are regulated by several shared processes such as post-translational modification, phosphorylation, activation by guanine exchange factors and inhibition by GTPase-activating proteins. Sub-cellular localization and trafficking of these proteins to and from the plasma membrane are additional important regulatory features that impact small GTPases function. Despite its importance, the trafficking mechanisms of Ras and Rap proteins are not completely understood. Chaperone proteins play a critical role in trafficking of GTPases and will be the focus of the discussion in this work. We will review several aspects of chaperone biology focusing on specificity toward particular members of the small GTPase family. Understanding this specificity should provide key insights into drug development targeting individual small GTPases.
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49
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Palsuledesai CC, Ochocki JD, Markowski TW, Distefano MD. A combination of metabolic labeling and 2D-DIGE analysis in response to a farnesyltransferase inhibitor facilitates the discovery of new prenylated proteins. MOLECULAR BIOSYSTEMS 2014; 10:1094-103. [PMID: 24577581 DOI: 10.1039/c3mb70593e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Protein prenylation is a post-translational modification required for proper cellular localization and activity of many important eukaryotic proteins. Farnesyltransferase inhibitors (FTIs) have been explored extensively for their antitumor activity. To assist in identifying potentially new and more useful markers for therapeutic applications, we developed a strategy that uses a combination of metabolic labeling and 2D DIGE (differential gel electrophoresis) to discover new prenylated proteins whose cellular levels are influenced by FTIs. In this approach, metabolic labeling of prenylated proteins was first carried out with an alkyne-modified isoprenoid analog, C15Alk, in the presence or absence of the FTI L-744,832. The resulting alkyne-tagged proteins were then labeled with Cy3-N3 and Cy5-N3 and subjected to 2D-DIGE. Multiple spots having altered levels of labeling in presence of the FTI were observed. Mass spectrometric analysis of some of the differentially labeled spots identified several known prenylated proteins, along with HisRS, PACN-3, GNAI-1 and GNAI-2, which are not known to be prenylated. In vitro farnesylation of a C-terminal peptide sequence derived from GNAI-1 and GNAI-2 produced a farnesylated product, suggesting GNAI-1 and GNAI-2 are potential novel farnesylated proteins. These results suggest that this new strategy could be useful for the identification of prenylated proteins whose level of post-translational modification has been modulated by the presence of an FTI. Additionally, this approach, which decreases sample complexity and thereby facilitates analysis, should be applicable to studies of other post-translational modifications as well.
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50
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Hou S, Grillo D, Williams CL, Wasserstrom JA, Szleifer I, Zhao M. Membrane phospholipid redistribution in cancer micro-particles and implications in the recruitment of cationic protein factors. J Extracell Vesicles 2014; 3:22653. [PMID: 24959330 PMCID: PMC4056184 DOI: 10.3402/jev.v3.22653] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 04/15/2014] [Accepted: 04/23/2014] [Indexed: 11/14/2022] Open
Abstract
Cancer cell-derived micro-particles (MPs) play important regulatory roles on cellular and system levels. These activities are attributed in part to protein factors carried by MPs. However, recruitment strategies for sequestering certain protein factors in MPs are poorly understood. In the current study, using exogenous and endogenously expressed phospholipid-binding probes, we investigated the distribution of membrane phospholipids in MPs as a potential mechanism for electrostatically enriching cationic protein factors in MPs. We detected a significant level of externalised phosphatidylethanolamine (PE) at the outer surface of MPs. This was accompanied, in the inner leaflet of the MP membrane, by a greater density of negatively charged phospholipids, particularly phosphatidylserine (PS). The local enrichment of PS in the inner surface of MPs was correlated with an elevated presence of small GTPases in a polybasic region (PBR)-dependent fashion. By employing a series of RhoA derivatives, including constitutively active and RhoA derivatives lacking a PBR, we could demonstrate that the congregation of RhoA in MPs was dependent on the presence of the PBR. A chimer with the fusion of PBR sequence alone to GFP significantly enhanced GFP localisation in MPs, indicative of a positive contribution of electrostatic interactions in RhoA recruitment to MPs. Using in silico thermodynamic simulations, we characterised the electrostatic interactions between PBR and anionic lipid membrane surface. In summary, the redistribution of membrane phospholipids in MPs has an impact on the local ionic density, and is likely a contributing factor in the electrostatic recruitment of membrane-associated proteins to MPs in a PBR-dependent fashion.
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Affiliation(s)
- Songwang Hou
- Department of Medicine, Northwestern University, Chicago, IL, USA
| | - Doris Grillo
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Carol L Williams
- Department of Pharmacology, Medical College of Wisconsin, Milwaukee, WI, USA
| | | | - Igal Szleifer
- Department of Medicine, Northwestern University, Chicago, IL, USA ; Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA ; Department of Biomedical Engineering and Department of Chemistry, Northwestern University, Evanston, IL, USA ; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
| | - Ming Zhao
- Department of Medicine, Northwestern University, Chicago, IL, USA ; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
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