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Noguera-Salvà MA, Guardiola-Serrano F, Martin ML, Marcilla-Etxenike A, Bergo MO, Busquets X, Escribá PV. Role of the C-terminal basic amino acids and the lipid anchor of the Gγ 2 protein in membrane interactions and cell localization. Biochim Biophys Acta Biomembr 2017; 1859:1536-1547. [PMID: 28235469 DOI: 10.1016/j.bbamem.2017.02.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/16/2017] [Accepted: 02/18/2017] [Indexed: 12/25/2022]
Abstract
Heterotrimeric G proteins are peripheral membrane proteins that frequently localize to the plasma membrane where their presence in molar excess over G protein coupled receptors permits signal amplification. Their distribution is regulated by protein-lipid interactions, which has a clear influence on their activity. Gβγ dimer drives the interaction between G protein heterotrimers with cell membranes. We focused our study on the role of the C-terminal region of the Gγ2 protein in G protein interactions with cell membranes. The Gγ2 subunit is modified at cysteine (Cys) 68 by the addition of an isoprenyl lipid, which is followed by the proteolytic removal of the last three residues that leaves an isoprenylated and carboxyl methylated Cys-68 as the terminal amino acid. The role of Cys isoprenylation of the CAAX box has been defined for other proteins, yet the importance of proteolysis and carboxyl methylation of isoprenylated proteins is less clear. Here, we showed that not only geranylgeranylation but also proteolysis and carboxyl methylation are essential for the correct localization of Gγ2 in the plasma membrane. Moreover, we showed the importance of electrostatic interactions between the inner leaflet of the plasma membrane and the positively charged C-terminal domain of the Gγ2 subunit (amino acids Arg-62, Lys-64 and Lys-65) as a second signal to reach the plasma membrane. Indeed, single or multiple point mutations at Gγ2 C-terminal amino acids have a significant effect on Gγ2 protein-plasma membrane interactions and its localization to charged Ld (liquid disordered) membrane microdomains. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.
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Affiliation(s)
- Maria A Noguera-Salvà
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma, Balearic Islands, Spain
| | - Francisca Guardiola-Serrano
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma, Balearic Islands, Spain
| | - M Laura Martin
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma, Balearic Islands, Spain
| | - Amaia Marcilla-Etxenike
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma, Balearic Islands, Spain
| | - Martin O Bergo
- Sahlgrenska Cancer Center, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Xavier Busquets
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma, Balearic Islands, Spain.
| | - Pablo V Escribá
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma, Balearic Islands, Spain
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Terés S, Lladó V, Higuera M, Barceló-Coblijn G, Martin ML, Noguera-Salvà MA, Marcilla-Etxenike A, García-Verdugo JM, Soriano-Navarro M, Saus C, Gómez-Pinedo U, Busquets X, Escribá PV. Normalization of sphingomyelin levels by 2-hydroxyoleic acid induces autophagic cell death of SF767 cancer cells. Autophagy 2012; 8:1542-4. [PMID: 22892762 DOI: 10.4161/auto.21341] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The very high mortality rate of gliomas reflects the unmet therapeutic need associated with this type of brain tumor. We have discovered that the plasma membrane fulfills a critical role in the propagation of tumorigenic signals, whereby changes in membrane lipid content can either activate or silence relevant pathways. We have designed a synthetic fatty acid, 2-hydroxyoleic acid (2OHOA), that specifically activates sphingomyelin synthase (SGMS), thereby modifying the lipid content of cancer cell membranes and restoring lipid levels to those found in normal cells. In reverting, the structure of the membrane by activating SGMS, 2OHOA inhibits the RAS-MAPK pathway, which in turn fails to activate the CCND (Cyclin D)-CDK4/CDK6 and PI3K-AKT1 pathways. The overall result in SF767 cancer cells, a line that is resistant to apoptosis, is the sequential induction of cell cycle arrest, cell differentiation and autophagy. Such effects are not observed in normal cells (MRC-5) and thus, this specific activation of programmed cell death infers greater efficacy and lower toxicity to 2OHOA than that associated with temozolomide (TMZ), the reference drug for the treatment of glioma.
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Affiliation(s)
- Silvia Terés
- Molecular Cell Biomedicine, Department of Biology-IUNICS, University of the Balearic Islands, Palma de Mallorca, Spain
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Terés S, Lladó V, Higuera M, Barceló-Coblijn G, Martin ML, Noguera-Salvà MA, Marcilla-Etxenike A, García-Verdugo JM, Soriano-Navarro M, Saus C, Gómez-Pinedo U, Busquets X, Escribá PV. 2-Hydroxyoleate, a nontoxic membrane binding anticancer drug, induces glioma cell differentiation and autophagy. Proc Natl Acad Sci U S A 2012; 109:8489-94. [PMID: 22586083 PMCID: PMC3365159 DOI: 10.1073/pnas.1118349109] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite recent advances in the development of new cancer therapies, the treatment options for glioma remain limited, and the survival rate of patients has changed little over the past three decades. Here, we show that 2-hydroxyoleic acid (2OHOA) induces differentiation and autophagy of human glioma cells. Compared to the current reference drug for this condition, temozolomide (TMZ), 2OHOA combated glioma more efficiently and, unlike TMZ, tumor relapse was not observed following 2OHOA treatment. The novel mechanism of action of 2OHOA is associated with important changes in membrane-lipid composition, primarily a recovery of sphingomyelin (SM) levels, which is markedly low in glioma cells before treatment. Parallel to membrane-lipid regulation, treatment with 2OHOA induced a dramatic translocation of Ras from the membrane to the cytoplasm, which inhibited the MAP kinase pathway, reduced activity of the PI3K/Akt pathway, and downregulated Cyclin D-CDK4/6 proteins followed by hypophosphorylation of the retinoblastoma protein (RB). These regulatory effects were associated with induction of glioma cell differentiation into mature glial cells followed by autophagic cell death. Given its high efficacy, low toxicity, ease of oral administration, and good distribution to the brain, 2OHOA constitutes a new and potentially valuable therapeutic tool for glioma patients.
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Affiliation(s)
- Silvia Terés
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - Victoria Lladó
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - Mónica Higuera
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - Gwendolyn Barceló-Coblijn
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - Maria Laura Martin
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - Maria Antònia Noguera-Salvà
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - Amaia Marcilla-Etxenike
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - José Manuel García-Verdugo
- Laboratorio de Morfología Celular, Unidad Mixta Centro de Investigación Príncipe Felipe-Universitat de València Estudi General, Centro de Investigación Biomédica en Red, Enfermedades Neurodegenerativas, 46013 Valencia, Spain; and
| | - Mario Soriano-Navarro
- Laboratorio de Morfología Celular, Unidad Mixta Centro de Investigación Príncipe Felipe-Universitat de València Estudi General, Centro de Investigación Biomédica en Red, Enfermedades Neurodegenerativas, 46013 Valencia, Spain; and
| | - Carlos Saus
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - Ulises Gómez-Pinedo
- Laboratory of Regenerative Medicine, Neuroscience Institute, Hospital Clínico San Carlos, 28040 Madrid, Spain
| | - Xavier Busquets
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
| | - Pablo V. Escribá
- Molecular Cell Biomedicine, Department of Biology-Institut Universitari d’Investigacions en Ciències de la Salut, University of the Balearic Islands, 07122 Palma de Mallorca, Spain
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Marcilla-Etxenike A, Busquets X, Barceló JM, Escribá PV. Minerval induces ER stress, G2/M phase arrest and autophagy in astrocitoma 1321N1 cells but not in MRC-5 fibroblast cells. Chem Phys Lipids 2010. [DOI: 10.1016/j.chemphyslip.2010.05.189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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