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Kava E, Garbelotti CV, Lopes JLS, Costa-Filho AJ. Myristoylated GRASP55 dimerizes in the presence of model membranes. J Biomol Struct Dyn 2024:1-12. [PMID: 38361284 DOI: 10.1080/07391102.2024.2317973] [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: 10/13/2023] [Accepted: 02/07/2024] [Indexed: 02/17/2024]
Abstract
The Golgi Reassembly and Stacking Proteins (GRASPs) are engaged in various functions within the cell, both in unconventional secretion mechanisms and structuring and organizing the Golgi apparatus. Understanding their specific role in each situation still requires more structural and functional data at the molecular level. GRASP55 is one of the GRASP members in mammals, anchored to the membrane via the myristoylation of a Gly residue at its N-terminus. Therefore, co-translational modifications, such as myristoylation, are fundamental when considering a strategy to obtain detailed information on the interactions between GRASP55 and membranes. Despite its functional relevance, the N-terminal myristoylation has been underappreciated in the studies reported to date, compromising the previously proposed models for GRASP-membrane interactions. Here, we investigated the synergy between the presence of the membrane and the formation of oligomeric structures of myristoylated GRASP55, using a series of biophysical techniques to perform the structural characterization of the lipidated GRASP55 and its interaction with biological lipid model membranes. Our data fulfill an unexplored gap: the adequate evaluation of the presence of lipidations and lipid membranes on the structure-function dyad of GRASPs.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Emanuel Kava
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Carolina V Garbelotti
- Laboratório de Fisiologia Ecológica de Plantas, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - José Luiz S Lopes
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Antonio J Costa-Filho
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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Berning L, Lenz T, Bergmann AK, Poschmann G, Brass HUC, Schlütermann D, Friedrich A, Mendiburo MJ, David C, Akgün S, Pietruszka J, Stühler K, Stork B. The Golgi stacking protein GRASP55 is targeted by the natural compound prodigiosin. Cell Commun Signal 2023; 21:275. [PMID: 37798768 PMCID: PMC10552397 DOI: 10.1186/s12964-023-01275-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/13/2023] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND The bacterial secondary metabolite prodigiosin has been shown to exert anticancer, antimalarial, antibacterial and immunomodulatory properties. With regard to cancer, it has been reported to affect cancer cells but not non-malignant cells, rendering prodigiosin a promising lead compound for anticancer drug discovery. However, a direct protein target has not yet been experimentally identified. METHODS We used mass spectrometry-based thermal proteome profiling in order to identify target proteins of prodigiosin. For target validation, we employed a genetic knockout approach and electron microscopy. RESULTS We identified the Golgi stacking protein GRASP55 as target protein of prodigiosin. We show that prodigiosin treatment severely affects Golgi morphology and functionality, and that prodigiosin-dependent cytotoxicity is partially reduced in GRASP55 knockout cells. We also found that prodigiosin treatment results in decreased cathepsin activity and overall blocks autophagic flux, whereas co-localization of the autophagosomal marker LC3 and the lysosomal marker LAMP1 is clearly promoted. Finally, we observed that autophagosomes accumulate at GRASP55-positive structures, pointing towards an involvement of an altered Golgi function in the autophagy-inhibitory effect of this natural compound. CONCLUSION Taken together, we propose that prodigiosin affects autophagy and Golgi apparatus integrity in an interlinked mode of action involving the regulation of organelle alkalization and the Golgi stacking protein GRASP55. Video Abstract.
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Affiliation(s)
- Lena Berning
- Institute of Molecular Medicine I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - Thomas Lenz
- Molecular Proteomics Laboratory, Biological Medical Research Centre, Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Ann Kathrin Bergmann
- Core Facility for Electron Microscopy, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - Gereon Poschmann
- Institute of Molecular Medicine I, Proteome Research, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - Hannah U C Brass
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf at Forschungszentrum Jülich and Bioeconomy Science Center (BioSC), 52426, Jülich, Germany
| | - David Schlütermann
- Institute of Molecular Medicine I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - Annabelle Friedrich
- Institute of Molecular Medicine I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - María José Mendiburo
- Institute of Molecular Medicine I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - Céline David
- Institute of Molecular Medicine I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - Seda Akgün
- Institute of Molecular Medicine I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - Jörg Pietruszka
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf at Forschungszentrum Jülich and Bioeconomy Science Center (BioSC), 52426, Jülich, Germany
- Institute of Bio- and Geosciences: Biotechnology (IBG-1), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Kai Stühler
- Molecular Proteomics Laboratory, Biological Medical Research Centre, Heinrich Heine University, 40225, Düsseldorf, Germany
- Institute of Molecular Medicine I, Proteome Research, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany
| | - Björn Stork
- Institute of Molecular Medicine I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, 40225, Germany.
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Kava E, Mendes LFS, Batista MRB, Costa-Filho AJ. Myristoylation and its effects on the human Golgi Reassembly and Stacking Protein 55. Biophys Chem 2021; 279:106690. [PMID: 34600312 DOI: 10.1016/j.bpc.2021.106690] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/14/2021] [Accepted: 09/18/2021] [Indexed: 10/20/2022]
Abstract
GRASP55 is a myristoylated protein localized in the medial/trans-Golgi faces and involved in the Golgi structure maintenance and the regulation of unconventional secretion pathways. It is believed that GRASP55 achieves its main functionalities in the Golgi organization by acting as a tethering factor. When bound to the lipid bilayer, its orientation relative to the membrane surface is restricted to determine its proper trans-oligomerization. Despite the paramount role of myristoylation in GRASP function, the impact of such protein modification on the membrane-anchoring properties and the structural organization of GRASP remains elusive. Here, an optimized protocol for the myristoylation in E. coli of the membrane-anchoring domain of GRASP55 is presented. The biophysical properties of the myristoylated/non-myristoylated GRASP55 GRASP domain were characterized in a membrane-mimicking micellar environment. Although myristoylation did not cause any impact on the protein's secondary structure, according to our circular dichroism data, it had a significant impact on the protein's thermal stability and solubility. Electrophoresis of negatively charged liposomes incubated with the two GRASP55 constructions showed different electrophoretic mobility for the myristoylated anchored protein only, thus demonstrating that myristoylation is essential for the biological membrane anchoring. Molecular dynamics simulations were used to further explore the anchoring process in determining the restricted orientation of GRASPs in the membrane.
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Affiliation(s)
- Emanuel Kava
- Molecular Biophysics Laboratory, Ribeirão Preto School of Philosophy, Sciences and Literature, Physics Department, University of São Paulo, Ribeirão Preto, Brazil
| | - Luis F S Mendes
- Molecular Biophysics Laboratory, Ribeirão Preto School of Philosophy, Sciences and Literature, Physics Department, University of São Paulo, Ribeirão Preto, Brazil
| | - Mariana R B Batista
- Molecular Biophysics Laboratory, Ribeirão Preto School of Philosophy, Sciences and Literature, Physics Department, University of São Paulo, Ribeirão Preto, Brazil
| | - Antonio J Costa-Filho
- Molecular Biophysics Laboratory, Ribeirão Preto School of Philosophy, Sciences and Literature, Physics Department, University of São Paulo, Ribeirão Preto, Brazil.
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