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Li YE, Norris DM, Xiao FN, Pandzic E, Whan RM, Fok S, Zhou M, Du G, Liu Y, Du X, Yang H. Phosphatidylserine regulates plasma membrane repair through tetraspanin-enriched macrodomains. J Cell Biol 2024; 223:e202307041. [PMID: 38530252 PMCID: PMC10964951 DOI: 10.1083/jcb.202307041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/30/2023] [Accepted: 03/11/2024] [Indexed: 03/27/2024] Open
Abstract
The integrity of the plasma membrane is critical to cell function and survival. Cells have developed multiple mechanisms to repair damaged plasma membranes. A key process during plasma membrane repair is to limit the size of the damage, which is facilitated by the presence of tetraspanin-enriched rings surrounding damage sites. Here, we identify phosphatidylserine-enriched rings surrounding damaged sites of the plasma membrane, resembling tetraspanin-enriched rings. Importantly, the formation of both the phosphatidylserine- and tetraspanin-enriched rings requires phosphatidylserine and its transfer proteins ORP5 and ORP9. Interestingly, ORP9, but not ORP5, is recruited to the damage sites, suggesting cells acquire phosphatidylserine from multiple sources upon plasma membrane damage. We further demonstrate that ORP9 contributes to efficient plasma membrane repair. Our results thus unveil a role for phosphatidylserine and its transfer proteins in facilitating the formation of tetraspanin-enriched macrodomains and plasma membrane repair.
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Affiliation(s)
- Yang E. Li
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Dougall M. Norris
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Fanqian N. Xiao
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Elvis Pandzic
- Katerina Gaus Light Microscopy Facility, Mark Wainwright Analytical Center, University of New South Wales, Sydney, Australia
| | - Renee M. Whan
- Katerina Gaus Light Microscopy Facility, Mark Wainwright Analytical Center, University of New South Wales, Sydney, Australia
| | - Sandra Fok
- Katerina Gaus Light Microscopy Facility, Mark Wainwright Analytical Center, University of New South Wales, Sydney, Australia
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Guangwei Du
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Yang Liu
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Ximing Du
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
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2
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Arora N, Liang H, Yao W, Ying H, Liu J, Zhou Y. Lysophosphatidylcholine acyltransferase 1 suppresses nanoclustering and function of KRAS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596653. [PMID: 38853864 PMCID: PMC11160780 DOI: 10.1101/2024.05.30.596653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
KRAS is frequently mutated in cancer, contributing to 20% of all human cancer especially pancreatic, colorectal and lung cancer. Signaling of the constitutively active KRAS oncogenic mutants is mostly compartmentalized to proteolipid nanoclusters on the plasma membrane (PM). Signaling nanoclusters of many KRAS mutants selectively enrich phosphatidylserine (PS) lipids with unsaturated sn-2 acyl chains, but not the fully saturated PS species. Thus, remodeling PS acyl chains may suppress KRAS oncogenesis. Lysophosphatidylcholine acyltransferases (LPCATs) remodel sn-2 acyl chains of phospholipids, with LPCAT1 preferentially generating the fully saturated lipids. Here, we show that stable expression of LPCAT1 depletes major PS species with unsaturated sn-2 chains while decreasing minor phosphatidylcholine (PC) species with the corresponding acyl chains. LPCAT1 expression more effectively disrupts the nanoclustering of oncogenic GFP-KRASG12V, which is restored by acute addback of exogenous unsaturated PS. LPCAT1 expression compromises signaling and oncogenic activities of the KRAS-dependent pancreatic tumor lines. LPCAT1 expression sensitizes human pancreatic tumor MiaPaCa-2 cells to KRASG12C specific inhibitor, Sotorasib. Statistical analyses of patient data further reveal that pancreatic cancer patients with KRAS mutations express less LPCAT1. Higher LPCAT1 expression also improves survival probability of pancreatic and lung adenocarcinoma patients with KRAS mutations. Thus, PS acyl chain remodeling selectively suppresses KRAS oncogenesis.
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Affiliation(s)
- Neha Arora
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas, USA
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas, USA
| | - Wantong Yao
- Department of Translational Molecular Pathology, Division of Pathology-Lab Medicine Div, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Haoqiang Ying
- Department of Molecular and Cellular Oncology, Division of Basic Science Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Junchen Liu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas, USA
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas, USA
- Program of Biochemistry and Cell Biology, Graduate School of Biological Sciences, M. D. Anderson Cancer Center and University of Texas Health Science Center, Houston, Texas, USA
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3
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Henkels KM, Miller TE, Naji A, van der Hoeven R, Liang H, Zhou Y, Hammond GR, Hancock JF, Cho KJ. Myotubularin-related proteins regulate KRAS function by controlling plasma membrane levels of polyphosphoinositides and phosphatidylserine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576612. [PMID: 38328115 PMCID: PMC10849561 DOI: 10.1101/2024.01.22.576612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
KRAS is a small GTPase, ubiquitously expressed in mammalian cells, that functions as a molecular switch to regulate cell proliferation and differentiation. Oncogenic mutations that render KRAS constitutively active occur frequently in human cancers. KRAS must localize to the plasma membrane (PM) for biological activity. KRAS PM binding is mediated by interactions of the KRAS membrane anchor with phosphatidylserine (PtdSer), therefore, depleting PM PtdSer content abrogates KRAS PM binding and oncogenic function. From a genome-wide siRNA screen to search for genes that regulate KRAS PM localization, we identified a set of phosphatidylinositol (PI) 3-phosphatase family members: myotubularin-related (MTMR) proteins 2, 3, 4 and 7. Here we show that knockdown of MTMR 2/3/4/7 expression disrupts KRAS PM interactions. The molecular mechanism involves depletion of PM PI 4-phosphate (PI4P) levels, which in turn disrupts the subcellular localization and operation of oxysterol-binding protein related protein (ORP) 5, a PtdSer lipid transfer protein that maintains PM PtdSer content. Concomitantly, silencing MTMR 2/3/4/7 expression elevates PM levels of PI3P and reduces PM and total cellular levels of PtdSer. In summary we propose that the PI 3-phosphatase activity provided by MTMR proteins is required to generate PM PI for the synthesis of PM PI4P, which in turn, promotes the PM localization of PtdSer and KRAS.
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Affiliation(s)
- Karen M. Henkels
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio 45435, USA
| | - Taylor E. Miller
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio 45435, USA
| | - Ali Naji
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Ransome van der Hoeven
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Gerald R.V. Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - John F. Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Kwang-jin Cho
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio 45435, USA
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4
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Rehl KM, Selvakumar J, Pitsch RL, Hoang D, Arumugam K, Harshman SW, Gorfe AA, Cho KJ. A new ferrocene derivative blocks K-Ras localization and function by oxidative modification at His95. Life Sci Alliance 2023; 6:e202302094. [PMID: 37666666 PMCID: PMC10477449 DOI: 10.26508/lsa.202302094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/06/2023] Open
Abstract
Ras proteins are membrane-bound GTPases that regulate essential cellular processes at the plasma membrane (PM). Constitutively active mutations of K-Ras, one of the three Ras isoforms in mammalian cells, are frequently found in human cancers. Ferrocene derivatives, which elevate cellular reactive oxygen species (ROS), have shown to block the growth of non-small cell lung cancers harboring oncogenic mutant K-Ras. Here, we tested a novel ferrocene derivative on the growth of pancreatic ductal adenocarcinoma and non-small cell lung cancer. Our compound, which elevated cellular ROS levels, inhibited the growth of K-Ras-driven cancers, and abrogated the PM binding and signaling of K-Ras in an isoform-specific manner. These effects were reversed upon antioxidant supplementation, suggesting a ROS-mediated mechanism. We further identified that K-Ras His95 residue plays an important role in this process, and it is putatively oxidized by cellular ROS. Together, our study demonstrates that the redox system directly regulates K-Ras/PM binding and signaling via oxidative modification at the His95, and proposes a role of oncogenic mutant K-Ras in the recently described antioxidant-induced growth and metastasis of K-Ras-driven cancers.
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Affiliation(s)
- Kristen M Rehl
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Jayaraman Selvakumar
- Department of Chemistry, College of Science and Mathematics, Wright State University, Dayton, OH, USA
| | - Rhonda L Pitsch
- https://ror.org/02e2egq70 Air Force Research Laboratory, Wright-Patterson AFB, OH, USA
| | - Don Hoang
- Department of Chemistry, College of Science and Mathematics, Wright State University, Dayton, OH, USA
| | - Kuppuswamy Arumugam
- Department of Chemistry, College of Science and Mathematics, Wright State University, Dayton, OH, USA
| | - Sean W Harshman
- https://ror.org/02e2egq70 Air Force Research Laboratory, Wright-Patterson AFB, OH, USA
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - Kwang-Jin Cho
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
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5
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Llorente A, Loughran RM, Emerling BM. Targeting phosphoinositide signaling in cancer: relevant techniques to study lipids and novel avenues for therapeutic intervention. Front Cell Dev Biol 2023; 11:1297355. [PMID: 37954209 PMCID: PMC10634348 DOI: 10.3389/fcell.2023.1297355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 10/12/2023] [Indexed: 11/14/2023] Open
Abstract
Phosphoinositides serve as essential players in numerous biological activities and are critical for overall cellular function. Due to their complex chemical structures, localization, and low abundance, current challenges in the phosphoinositide field include the accurate measurement and identification of specific variants, particularly those with acyl chains. Researchers are intensively developing innovative techniques and approaches to address these challenges and advance our understanding of the impact of phosphoinositide signaling on cellular biology. This article provides an overview of recent advances in the study of phosphoinositides, including mass spectrometry, lipid biosensors, and real-time activity assays using fluorometric sensors. These methodologies have proven instrumental for a comprehensive exploration of the cellular distribution and dynamics of phosphoinositides and have shed light on the growing significance of these lipids in human health and various pathological processes, including cancer. To illustrate the importance of phosphoinositide signaling in disease, this perspective also highlights the role of a family of lipid kinases named phosphatidylinositol 5-phosphate 4-kinases (PI5P4Ks), which have recently emerged as exciting therapeutic targets for cancer treatment. The ongoing exploration of phosphoinositide signaling not only deepens our understanding of cellular biology but also holds promise for novel interventions in cancer therapy.
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Affiliation(s)
| | | | - Brooke M. Emerling
- Cancer Metabolism and Microenvironment Program, Sanford Burnham Prebys, La Jolla, CA, United States
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6
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Entrialgo-Cadierno R, Cueto-Ureña C, Welch C, Feliu I, Macaya I, Vera L, Morales X, Michelina SV, Scaparone P, Lopez I, Darbo E, Erice O, Vallejo A, Moreno H, Goñi-Salaverri A, Lara-Astiaso D, Halberg N, Cortes-Dominguez I, Guruceaga E, Ambrogio C, Lecanda F, Vicent S. The phospholipid transporter PITPNC1 links KRAS to MYC to prevent autophagy in lung and pancreatic cancer. Mol Cancer 2023; 22:86. [PMID: 37210549 DOI: 10.1186/s12943-023-01788-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 05/11/2023] [Indexed: 05/22/2023] Open
Abstract
BACKGROUND The discovery of functionally relevant KRAS effectors in lung and pancreatic ductal adenocarcinoma (LUAD and PDAC) may yield novel molecular targets or mechanisms amenable to inhibition strategies. Phospholipids availability has been appreciated as a mechanism to modulate KRAS oncogenic potential. Thus, phospholipid transporters may play a functional role in KRAS-driven oncogenesis. Here, we identified and systematically studied the phospholipid transporter PITPNC1 and its controlled network in LUAD and PDAC. METHODS Genetic modulation of KRAS expression as well as pharmacological inhibition of canonical effectors was completed. PITPNC1 genetic depletion was performed in in vitro and in vivo LUAD and PDAC models. PITPNC1-deficient cells were RNA sequenced, and Gene Ontology and enrichment analyses were applied to the output data. Protein-based biochemical and subcellular localization assays were run to investigate PITPNC1-regulated pathways. A drug repurposing approach was used to predict surrogate PITPNC1 inhibitors that were tested in combination with KRASG12C inhibitors in 2D, 3D, and in vivo models. RESULTS PITPNC1 was increased in human LUAD and PDAC, and associated with poor patients' survival. PITPNC1 was regulated by KRAS through MEK1/2 and JNK1/2. Functional experiments showed PITPNC1 requirement for cell proliferation, cell cycle progression and tumour growth. Furthermore, PITPNC1 overexpression enhanced lung colonization and liver metastasis. PITPNC1 regulated a transcriptional signature which highly overlapped with that of KRAS, and controlled mTOR localization via enhanced MYC protein stability to prevent autophagy. JAK2 inhibitors were predicted as putative PITPNC1 inhibitors with antiproliferative effect and their combination with KRASG12C inhibitors elicited a substantial anti-tumour effect in LUAD and PDAC. CONCLUSIONS Our data highlight the functional and clinical relevance of PITPNC1 in LUAD and PDAC. Moreover, PITPNC1 constitutes a new mechanism linking KRAS to MYC, and controls a druggable transcriptional network for combinatorial treatments.
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Affiliation(s)
- Rodrigo Entrialgo-Cadierno
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | - Cristina Cueto-Ureña
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | - Connor Welch
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain
| | - Iker Feliu
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | - Irati Macaya
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | - Laura Vera
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | - Xabier Morales
- Imaging Unit and Cancer Imaging Laboratory, University of Navarra, CIMA, Pamplona, Spain
| | - Sandra Vietti Michelina
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Centre, University of Torino, Turin, Italy
| | - Pietro Scaparone
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Centre, University of Torino, Turin, Italy
| | - Ines Lopez
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | - Elodie Darbo
- University of Bordeaux, INSERM, BRIC, U 1312, F-33000, Bordeaux, France
| | - Oihane Erice
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | - Adrian Vallejo
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | - Haritz Moreno
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
| | | | - David Lara-Astiaso
- Molecular Therapies Program, University of Navarra, CIMA, Pamplona, Spain
- Wellcome - MRC Cambridge Stem Cell Institute (CSCI), Cambridge, UK
| | - Nils Halberg
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Ivan Cortes-Dominguez
- Imaging Unit and Cancer Imaging Laboratory, University of Navarra, CIMA, Pamplona, Spain
- Bioinformatics Platform, University of Navarra, CIMA, Pamplona, Spain
| | - Elizabeth Guruceaga
- Bioinformatics Platform, University of Navarra, CIMA, Pamplona, Spain
- IdiSNA, Navarra Institute for Health Research, Pamplona, Spain
| | - Chiara Ambrogio
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Centre, University of Torino, Turin, Italy
| | - Fernando Lecanda
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain
- IdiSNA, Navarra Institute for Health Research, Pamplona, Spain
- Department of Pathology, Anatomy and Physiology, University of Navarra, Pamplona, Spain
| | - Silve Vicent
- Program in Solid Tumours, University of Navarra, Centre of Applied Medical Research (CIMA), 55 Pio XII Avenue, 31008, Pamplona, Spain.
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain.
- IdiSNA, Navarra Institute for Health Research, Pamplona, Spain.
- Department of Pathology, Anatomy and Physiology, University of Navarra, Pamplona, Spain.
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7
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Rehl KM, Selvakumar J, Hoang D, Arumugam K, Gorfe AA, Cho KJ. A new ferrocene derivative blocks KRAS localization and function by oxidative modification at His95. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534499. [PMID: 37034642 PMCID: PMC10081197 DOI: 10.1101/2023.03.28.534499] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Ras proteins are membrane-bound GTPases that regulate essential cellular processes at the plasma membrane (PM). Constitutively active mutations of K-Ras, one of the three Ras isoforms in mammalian cells, are frequently found in human cancers. Ferrocene derivatives, which elevate cellular reactive oxygen species (ROS), have shown to block the growth of non-small cell lung cancers (NSCLCs) harboring oncogenic mutant K-Ras. Here, we developed and tested a novel ferrocene derivative on the growth of human pancreatic ductal adenocarcinoma (PDAC) and NSCLC. Our compound inhibited the growth of K-Ras-dependent PDAC and NSCLC and abrogated the PM binding and signaling of K-Ras, but not other Ras isoforms. These effects were reversed upon antioxidant supplementation, suggesting a ROS-mediated mechanism. We further identified K-Ras His95 residue in the G-domain as being involved in the ferrocene-induced K-Ras PM dissociation via oxidative modification. Together, our studies demonstrate that the redox system directly regulates K-Ras PM binding and signaling via oxidative modification at the His95, and proposes a role of oncogenic mutant K-Ras in the recently described antioxidant-induced metastasis in K-Ras-driven lung cancers.
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8
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Zhou Y, Hancock JF. RAS nanoclusters are cell surface transducers that convert extracellular stimuli to intracellular signalling. FEBS Lett 2023; 597:892-908. [PMID: 36595205 PMCID: PMC10919257 DOI: 10.1002/1873-3468.14569] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/05/2022] [Accepted: 12/12/2022] [Indexed: 01/04/2023]
Abstract
Mutations of rat sarcoma virus (RAS) oncogenes (HRAS, KRAS and NRAS) can contribute to the development of cancers and genetic disorders (RASopathies). The spatiotemporal organization of RAS is an important property that warrants further investigation. In order to function, wild-type or oncogenic mutants of RAS must be localized to the inner leaflet of the plasma membrane (PM), which is driven by interactions between their C-terminal membrane-anchoring domains and PM lipids. The isoform-specific RAS-lipid interactions promote the formation of nanoclusters on the PM. As main sites for effector recruitment, these nanoclusters are biologically important. Since the spatial distribution of lipids is sensitive to changing environments, such as mechanical and electrical perturbations, RAS nanoclusters act as transducers to convert external stimuli to intracellular mitogenic signalling. As such, effective inhibition of RAS oncogenesis requires consideration of the complex interplay between RAS nanoclusters and various cell surface and extracellular stimuli. In this review, we discuss in detail how, by sorting specific lipids in the PM, RAS nanoclusters act as transducers to convert external stimuli into intracellular signalling.
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Affiliation(s)
- Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, McGovern Medical School, TX, USA
- Graduate School of Biomedical Sciences, University of Texas MD Anderson Cancer Center and University of Texas Health Science Center, TX, USA
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, McGovern Medical School, TX, USA
- Graduate School of Biomedical Sciences, University of Texas MD Anderson Cancer Center and University of Texas Health Science Center, TX, USA
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9
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Glycolysis regulates KRAS plasma membrane localization and function through defined glycosphingolipids. Nat Commun 2023; 14:465. [PMID: 36709325 PMCID: PMC9884228 DOI: 10.1038/s41467-023-36128-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 01/17/2023] [Indexed: 01/29/2023] Open
Abstract
Oncogenic KRAS expression generates a metabolic dependency on aerobic glycolysis, known as the Warburg effect. We report an effect of increased glycolytic flux that feeds into glycosphingolipid biosynthesis and is directly linked to KRAS oncogenic function. High resolution imaging and genetic approaches show that a defined subset of outer leaflet glycosphingolipids, including GM3 and SM4, is required to maintain KRAS plasma membrane localization, with GM3 engaging in cross-bilayer coupling to maintain inner leaflet phosphatidylserine content. Thus, glycolysis is critical for KRAS plasma membrane localization and nanoscale spatial organization. Reciprocally oncogenic KRAS selectively upregulates cellular content of these same glycosphingolipids, whose depletion in turn abrogates KRAS oncogenesis in pancreatic cancer models. Our findings expand the role of the Warburg effect beyond ATP generation and biomass building to high-level regulation of KRAS function. The positive feedforward loop between oncogenic KRAS signaling and glycosphingolipid synthesis represents a vulnerability with therapeutic potential.
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10
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Nanoscopic Spatial Association between Ras and Phosphatidylserine on the Cell Membrane Studied with Multicolor Super Resolution Microscopy. Biomolecules 2022; 12:biom12081033. [PMID: 35892343 PMCID: PMC9332490 DOI: 10.3390/biom12081033] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 07/02/2022] [Accepted: 07/22/2022] [Indexed: 11/17/2022] Open
Abstract
Recent work suggests that Ras small GTPases interact with the anionic lipid phosphatidylserine (PS) in an isoform-specific manner, with direct implications for their biological functions. Studies on PS-Ras associations in cells, however, have relied on immuno-EM imaging of membrane sheets. To study their spatial relationships in intact cells, we have combined the use of Lact-C2-GFP, a biosensor for PS, with multicolor super resolution imaging based on DNA-PAINT. At ~20 nm spatial resolution, the resulting super resolution images clearly show the nonuniform molecular distribution of PS on the cell membrane and its co-enrichment with caveolae, as well as with unidentified membrane structures. Two-color imaging followed by spatial analysis shows that KRas-G12D and HRas-G12V both co-enrich with PS in model U2OS cells, confirming previous observations, yet exhibit clear differences in their association patterns. Whereas HRas-G12V is almost always co-enriched with PS, KRas-G12D is strongly co-enriched with PS in about half of the cells, with the other half exhibiting a more moderate association. In addition, perturbations to the actin cytoskeleton differentially impact PS association with the two Ras isoforms. These results suggest that PS-Ras association is context-dependent and demonstrate the utility of multiplexed super resolution imaging in defining the complex interplay between Ras and the membrane.
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11
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Ventura R, Martínez-Ruiz I, Hernández-Alvarez MI. Phospholipid Membrane Transport and Associated Diseases. Biomedicines 2022; 10:biomedicines10051201. [PMID: 35625937 PMCID: PMC9138374 DOI: 10.3390/biomedicines10051201] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 11/16/2022] Open
Abstract
Phospholipids are the basic structure block of eukaryotic membranes, in both the outer and inner membranes, which delimit cell organelles. Phospholipids can also be damaged by oxidative stress produced by mitochondria, for instance, becoming oxidized phospholipids. These damaged phospholipids have been related to prevalent diseases such as atherosclerosis or non-alcoholic steatohepatitis (NASH) because they alter gene expression and induce cellular stress and apoptosis. One of the main sites of phospholipid synthesis is the endoplasmic reticulum (ER). ER association with other organelles through membrane contact sites (MCS) provides a close apposition for lipid transport. Additionally, an important advance in this small cytosolic gap are lipid transfer proteins (LTPs), which accelerate and modulate the distribution of phospholipids in other organelles. In this regard, LTPs can be established as an essential point within phospholipid circulation, as relevant data show impaired phospholipid transport when LTPs are defected. This review will focus on phospholipid function, metabolism, non-vesicular transport, and associated diseases.
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Affiliation(s)
- Raúl Ventura
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain; (R.V.); (I.M.-R.)
| | - Inma Martínez-Ruiz
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain; (R.V.); (I.M.-R.)
| | - María Isabel Hernández-Alvarez
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain; (R.V.); (I.M.-R.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, 28029 Madrid, Spain
- IBUB Universitat de Barcelona—Institut de Biomedicina de la Universitat de Barcelona, 08028 Barcelona, Spain
- Correspondence:
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12
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3,4,5-Trimethoxybenzoate of Catechin, an Anticarcinogenic Semisynthetic Catechin, Modulates the Physical Properties of Anionic Phospholipid Membranes. Molecules 2022; 27:molecules27092910. [PMID: 35566261 PMCID: PMC9105813 DOI: 10.3390/molecules27092910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 04/27/2022] [Accepted: 04/30/2022] [Indexed: 11/21/2022] Open
Abstract
3,4,5-Trimethoxybenzoate of catechin (TMBC) is a semisynthetic catechin which shows strong antiproliferative activity against malignant melanoma cells. The amphiphilic nature of the molecule suggests that the membrane could be a potential site of action, hence the study of its interaction with lipid bilayers is mandatory in order to gain information on the effect of the catechin on the membrane properties and dynamics. Anionic phospholipids, though being minor components of the membrane, possess singular physical and biochemical properties that make them physiologically essential. Utilizing phosphatidylserine biomimetic membranes, we study the interaction between the catechin and anionic bilayers, bringing together a variety of experimental techniques and molecular dynamics simulation. The experimental data suggest that the molecule is embedded into the phosphatidylserine bilayers, where it perturbs the thermotropic gel to liquid crystalline phase transition. In the gel phase, the catechin promotes the formation of interdigitation, and in the liquid crystalline phase, it decreases the bilayer thickness and increases the hydrogen bonding pattern of the interfacial region of the bilayer. The simulation data agree with the experimental ones and indicate that the molecule is located in the interior of the anionic bilayer as monomer and small clusters reaching the carbonyl region of the phospholipid, where it also disturbs the intermolecular hydrogen bonding between neighboring lipids. Our observations suggest that the catechin incorporates well into phosphatidylserine bilayers, where it produces structural changes that could affect the functioning of the membrane.
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13
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Shi Q, Chen J, Zou X, Tang X. Intracellular Cholesterol Synthesis and Transport. Front Cell Dev Biol 2022; 10:819281. [PMID: 35386193 PMCID: PMC8978673 DOI: 10.3389/fcell.2022.819281] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 02/01/2022] [Indexed: 12/18/2022] Open
Abstract
Cholesterol homeostasis is related to multiple diseases in humans, including cardiovascular disease, cancer, and neurodegenerative and hepatic diseases. The cholesterol levels in cells are balanced dynamically by uptake, biosynthesis, transport, distribution, esterification, and export. In this review, we focus on de novo cholesterol synthesis, cholesterol synthesis regulation, and intracellular cholesterol trafficking. In addition, the progression of lipid transfer proteins (LTPs) at multiple contact sites between organelles is considered.
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Affiliation(s)
- Qingyang Shi
- Center of Reproductive Medicine and Center of Prenatal Diagnosis, The First Hospital, Jilin University, Changchun, China
| | - Jiahuan Chen
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, China
| | - Xiaodong Zou
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, China
| | - Xiaochun Tang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, China
- Chongqing Research Institute of Jilin University, Chongqing, China
- *Correspondence: Xiaochun Tang,
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14
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Pavic K, Chippalkatti R, Abankwa D. Drug targeting opportunities en route to Ras nanoclusters. Adv Cancer Res 2022; 153:63-99. [PMID: 35101236 DOI: 10.1016/bs.acr.2021.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Disruption of the native membrane organization of Ras by the farnesyltransferase inhibitor tipifarnib in the late 1990s constituted the first indirect approach to drug target Ras. Since then, our understanding of how dynamically Ras shuttles between subcellular locations has changed significantly. Ras proteins have to arrive at the plasma membrane for efficient MAPK-signal propagation. On the plasma membrane Ras proteins are organized into isoform specific proteo-lipid assemblies called nanocluster. Recent evidence suggests that Ras nanocluster have a specific lipid composition, which supports the recruitment of effectors such as Raf. Conversely, effectors possess lipid-recognition motifs, which appear to serve as co-incidence detectors for the lipid domain of a given Ras isoform. Evidence suggests that dimeric Raf proteins then co-assemble dimeric Ras in an immobile complex, thus forming the minimal unit of an active nanocluster. Here we review established and novel trafficking chaperones and trafficking factors of Ras, along with the set of lipid and protein modulators of Ras nanoclustering. We highlight drug targeting approaches and opportunities against these determinants of functional Ras membrane organization. Finally, we reflect on implications for Ras signaling in polarized cells, such as epithelia, which are a common origin of tumorigenesis.
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Affiliation(s)
- Karolina Pavic
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Rohan Chippalkatti
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
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15
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Arora A, Taskinen JH, Olkkonen VM. Coordination of inter-organelle communication and lipid fluxes by OSBP-related proteins. Prog Lipid Res 2022; 86:101146. [PMID: 34999137 DOI: 10.1016/j.plipres.2022.101146] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/10/2021] [Accepted: 01/03/2022] [Indexed: 12/31/2022]
Abstract
Oxysterol-binding protein (OSBP) and OSBP-related proteins (ORPs) constitute one of the largest families of lipid-binding/transfer proteins (LTPs) in eukaryotes. The current view is that many of them mediate inter-organelle lipid transfer over membrane contact sites (MCS). The transfer occurs in several cases in a 'counter-current' fashion: A lipid such as cholesterol or phosphatidylserine (PS) is transferred against its concentration gradient driven by transport of a phosphoinositide in the opposite direction. In this way ORPs are envisioned to maintain the distinct organelle lipid compositions, with impacts on multiple organelle functions. However, the functions of ORPs extend beyond lipid homeostasis to regulation of processes such as cell survival, proliferation and migration. Important expanding areas of mammalian ORP research include their roles in viral and bacterial infections, cancers, and neuronal function. The yeast OSBP homologue (Osh) proteins execute multifaceted functions in sterol and glycerophospholipid homeostasis, post-Golgi vesicle transport, phosphatidylinositol-4-phosphate, sphingolipid and target of rapamycin (TOR) signalling, and cell cycle control. These observations identify ORPs as lipid transporters and coordinators of signals with an unforeseen variety of cellular processes. Understanding their activities not only enlightens the biology of the living cell but also allows their employment as targets of new therapeutic approaches for disease.
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Affiliation(s)
- Amita Arora
- Minerva Foundation Institute for Medical Research, and Department of Anatomy, Faculty of Medicine, University of Helsinki, Finland
| | - Juuso H Taskinen
- Minerva Foundation Institute for Medical Research, and Department of Anatomy, Faculty of Medicine, University of Helsinki, Finland
| | - Vesa M Olkkonen
- Minerva Foundation Institute for Medical Research, and Department of Anatomy, Faculty of Medicine, University of Helsinki, Finland.
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16
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Components of the phosphatidylserine endoplasmic reticulum to plasma membrane transport mechanism as targets for KRAS inhibition in pancreatic cancer. Proc Natl Acad Sci U S A 2021; 118:2114126118. [PMID: 34903667 DOI: 10.1073/pnas.2114126118] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2021] [Indexed: 12/19/2022] Open
Abstract
KRAS is mutated in 90% of human pancreatic ductal adenocarcinomas (PDACs). To function, KRAS must localize to the plasma membrane (PM) via a C-terminal membrane anchor that specifically engages phosphatidylserine (PtdSer). This anchor-binding specificity renders KRAS-PM localization and signaling capacity critically dependent on PM PtdSer content. We now show that the PtdSer lipid transport proteins, ORP5 and ORP8, which are essential for maintaining PM PtdSer levels and hence KRAS PM localization, are required for KRAS oncogenesis. Knockdown of either protein, separately or simultaneously, abrogated growth of KRAS-mutant but not KRAS-wild-type pancreatic cancer cell xenografts. ORP5 or ORP8 knockout also abrogated tumor growth in an immune-competent orthotopic pancreatic cancer mouse model. Analysis of human datasets revealed that all components of this PtdSer transport mechanism, including the PM-localized EFR3A-PI4KIIIα complex that generates phosphatidylinositol-4-phosphate (PI4P), and endoplasmic reticulum (ER)-localized SAC1 phosphatase that hydrolyzes counter transported PI4P, are significantly up-regulated in pancreatic tumors compared to normal tissue. Taken together, these results support targeting PI4KIIIα in KRAS-mutant cancers to deplete the PM-to-ER PI4P gradient, reducing PM PtdSer content. We therefore repurposed the US Food and Drug Administration-approved hepatitis C antiviral agent, simeprevir, as a PI4KIIIα inhibitor In a PDAC setting. Simeprevir potently mislocalized KRAS from the PM, reduced the clonogenic potential of pancreatic cancer cell lines in vitro, and abrogated the growth of KRAS-dependent tumors in vivo with enhanced efficacy when combined with MAPK and PI3K inhibitors. We conclude that the cellular ER-to-PM PtdSer transport mechanism is essential for KRAS PM localization and oncogenesis and is accessible to therapeutic intervention.
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17
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Zhou Y, Hancock JF. Lipid Profiles of RAS Nanoclusters Regulate RAS Function. Biomolecules 2021; 11:biom11101439. [PMID: 34680072 PMCID: PMC8533076 DOI: 10.3390/biom11101439] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 12/12/2022] Open
Abstract
The lipid-anchored RAS (Rat sarcoma) small GTPases (guanosine triphosphate hydrolases) are highly prevalent in human cancer. Traditional strategies of targeting the enzymatic activities of RAS have been shown to be difficult. Alternatively, RAS function and pathology are mostly restricted to nanoclusters on the plasma membrane (PM). Lipids are important structural components of these signaling platforms on the PM. However, how RAS nanoclusters selectively enrich distinct lipids in the PM, how different lipids contribute to RAS signaling and oncogenesis and whether the selective lipid sorting of RAS nanoclusters can be targeted have not been well-understood. Latest advances in quantitative super-resolution imaging and molecular dynamic simulations have allowed detailed characterization RAS/lipid interactions. In this review, we discuss the latest findings on the select lipid composition (with headgroup and acyl chain specificities) within RAS nanoclusters, the specific mechanisms for the select lipid sorting of RAS nanoclusters on the PM and how perturbing lipid compositions within RAS nanoclusters impacts RAS function and pathology. We also describe different strategies of manipulating lipid composition within RAS nanoclusters on the PM.
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18
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Li YP, Mikrani R, Hu YF, Faran Ashraf Baig MM, Abbas M, Akhtar F, Xu M. Research progress of phosphatidylinositol 4-kinase and its inhibitors in inflammatory diseases. Eur J Pharmacol 2021; 907:174300. [PMID: 34217706 DOI: 10.1016/j.ejphar.2021.174300] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 06/24/2021] [Accepted: 06/30/2021] [Indexed: 01/08/2023]
Abstract
Phosphatidylinositol 4-kinase (PI4K) is a lipid kinase that can catalyze the transfer of phosphate group from ATP to the inositol ring of phosphatidylinositol (PtdIns) resulting in the phosphorylation of PtdIns at 4-OH sites, to generate phosphatidylinositol 4-phosphate (PI4P). Studies on biological functions reveal that PI4K is closely related to the occurrence and development of various inflammatory diseases such as obesity, cancer, viral infections, malaria, Alzheimer's disease, etc. PI4K-related inhibitors have been found to have the effects of inhibiting virus replication, anti-cancer, treating malaria and reducing rejection in organ transplants, among which MMV390048, an anti-malaria drug, has entered phase II clinical trial. This review discusses the classification, structure, distribution and related inhibitors of PI4K and their role in the progression of cancer, viral replication, and other inflammation induced diseases to explore their potential as therapeutic targets.
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Affiliation(s)
- Yan-Ping Li
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Reyaj Mikrani
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria 3052, Australia
| | - Yi-Fan Hu
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Mirza Muhammad Faran Ashraf Baig
- Laboratory of Biomedical Engineering for Novel Bio-functional and Pharmaceutical Nano-materials, Prince Philip Dental Hospital, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, 999077, China
| | - Muhammad Abbas
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210023, PR China
| | - Fahad Akhtar
- State Key Laboratory of Molecular Development Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China; School of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ming Xu
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China.
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19
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Oncogenic KRAS is dependent upon an EFR3A-PI4KA signaling axis for potent tumorigenic activity. Nat Commun 2021; 12:5248. [PMID: 34504076 PMCID: PMC8429657 DOI: 10.1038/s41467-021-25523-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 08/10/2021] [Indexed: 11/15/2022] Open
Abstract
The HRAS, NRAS, and KRAS genes are collectively mutated in a fifth of all human cancers. These mutations render RAS GTP-bound and active, constitutively binding effector proteins to promote signaling conducive to tumorigenic growth. To further elucidate how RAS oncoproteins signal, we mined RAS interactomes for potential vulnerabilities. Here we identify EFR3A, an adapter protein for the phosphatidylinositol kinase PI4KA, to preferentially bind oncogenic KRAS. Disrupting EFR3A or PI4KA reduces phosphatidylinositol-4-phosphate, phosphatidylserine, and KRAS levels at the plasma membrane, as well as oncogenic signaling and tumorigenesis, phenotypes rescued by tethering PI4KA to the plasma membrane. Finally, we show that a selective PI4KA inhibitor augments the antineoplastic activity of the KRASG12C inhibitor sotorasib, suggesting a clinical path to exploit this pathway. In sum, we have discovered a distinct KRAS signaling axis with actionable therapeutic potential for the treatment of KRAS-mutant cancers. The lipid composition of the plasma membrane defines the localisation of KRAS and its oncogenic function. Here the authors show that EFR3A binds to active KRAS to recruit PI4KA and alters the lipid composition of the plasma membrane to promote KRAS oncogenic signalling and tumorigenesis.
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20
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Zhou Y, Gorfe AA, Hancock JF. RAS Nanoclusters Selectively Sort Distinct Lipid Headgroups and Acyl Chains. Front Mol Biosci 2021; 8:686338. [PMID: 34222339 PMCID: PMC8245699 DOI: 10.3389/fmolb.2021.686338] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
RAS proteins are lipid-anchored small GTPases that switch between the GTP-bound active and GDP-bound inactive states. RAS isoforms, including HRAS, NRAS and splice variants KRAS4A and KRAS4B, are some of the most frequently mutated proteins in cancer. In particular, constitutively active mutants of KRAS comprise ∼80% of all RAS oncogenic mutations and are found in 98% of pancreatic, 45% of colorectal and 31% of lung tumors. Plasma membrane (PM) is the primary location of RAS signaling in biology and pathology. Thus, a better understanding of how RAS proteins localize to and distribute on the PM is critical to better comprehend RAS biology and to develop new strategies to treat RAS pathology. In this review, we discuss recent findings on how RAS proteins sort lipids as they undergo macromolecular assembly on the PM. We also discuss how RAS/lipid nanoclusters serve as signaling platforms for the efficient recruitment of effectors and signal transduction, and how perturbing the PM biophysical properties affect the spatial distribution of RAS isoforms and their functions.
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Affiliation(s)
- Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, United States
| | - Alemayehu A. Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, United States
| | - John F. Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, United States
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21
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Henkels KM, Rehl KM, Cho KJ. Blocking K-Ras Interaction With the Plasma Membrane Is a Tractable Therapeutic Approach to Inhibit Oncogenic K-Ras Activity. Front Mol Biosci 2021; 8:673096. [PMID: 34222333 PMCID: PMC8244928 DOI: 10.3389/fmolb.2021.673096] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/20/2021] [Indexed: 12/12/2022] Open
Abstract
Ras proteins are membrane-bound small GTPases that promote cell proliferation, differentiation, and apoptosis. Consistent with this key regulatory role, activating mutations of Ras are present in ∼19% of new cancer cases in the United States per year. K-Ras is one of the three ubiquitously expressed isoforms in mammalian cells, and oncogenic mutations in this isoform account for ∼75% of Ras-driven cancers. Therefore, pharmacological agents that block oncogenic K-Ras activity would have great clinical utility. Most efforts to block oncogenic Ras activity have focused on Ras downstream effectors, but these inhibitors only show limited clinical benefits in Ras-driven cancers due to the highly divergent signals arising from Ras activation. Currently, four major approaches are being extensively studied to target K-Ras–driven cancers. One strategy is to block K-Ras binding to the plasma membrane (PM) since K-Ras requires the PM binding for its signal transduction. Here, we summarize recently identified molecular mechanisms that regulate K-Ras–PM interaction. Perturbing these mechanisms using pharmacological agents blocks K-Ras–PM binding and inhibits K-Ras signaling and growth of K-Ras–driven cancer cells. Together, these studies propose that blocking K-Ras–PM binding is a tractable strategy for developing anti–K-Ras therapies.
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Affiliation(s)
- Karen M Henkels
- Department of Biochemistry and Molecular Biology, School of Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Kristen M Rehl
- Department of Biochemistry and Molecular Biology, School of Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Kwang-Jin Cho
- Department of Biochemistry and Molecular Biology, School of Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
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22
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Wang P, van der Hoeven D, Ye N, Chen H, Liu Z, Ma X, Montufar-Solis D, Rehl KM, Cho KJ, Thapa S, Chen W, van der Hoeven R, Frost JA, Hancock JF, Zhou J. Scaffold repurposing of fendiline: Identification of potent KRAS plasma membrane localization inhibitors. Eur J Med Chem 2021; 217:113381. [PMID: 33756124 DOI: 10.1016/j.ejmech.2021.113381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 02/07/2023]
Abstract
KRAS plays an essential role in regulating cell proliferation, differentiation, migration and survival. Mutated KRAS is a major driver of malignant transformation in multiple human cancers. We showed previously that fendiline (6) is an effective inhibitor of KRAS plasma membrane (PM) localization and function. In this study, we designed, synthesized and evaluated a series of new fendiline analogs to optimize its drug properties. Systemic structure-activity relationship studies by scaffold repurposing led to the discovery of several more active KRAS PM localization inhibitors such as compounds 12f (NY0244), 12h (NY0331) and 22 (NY0335) which exhibit nanomolar potencies. These compounds inhibited oncogenic KRAS-driven cancer cell proliferation at single-digit micromolar concentrations in vitro. In vivo studies in a xenograft model of pancreatic cancer revealed that 12h and 22 suppressed oncogenic KRAS-expressing MiaPaCa-2 tumor growth at a low dose range of 1-5 mg/kg with no vasodilatory effects, indicating their potential as chemical probes and anticancer therapeutics.
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Affiliation(s)
- Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Dharini van der Hoeven
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, 77054, USA
| | - Na Ye
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Xiaoping Ma
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Dina Montufar-Solis
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Kristen M Rehl
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Kwang-Jin Cho
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Sabita Thapa
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, 77054, USA
| | - Wei Chen
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Ransome van der Hoeven
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, 77054, USA
| | - Jeffrey A Frost
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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23
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Zhou Y, Prakash PS, Liang H, Gorfe AA, Hancock JF. The KRAS and other prenylated polybasic domain membrane anchors recognize phosphatidylserine acyl chain structure. Proc Natl Acad Sci U S A 2021; 118:e2014605118. [PMID: 33526670 PMCID: PMC8017956 DOI: 10.1073/pnas.2014605118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
KRAS interacts with the inner leaflet of the plasma membrane (PM) using a hybrid anchor that comprises a lysine-rich polybasic domain (PBD) and a C-terminal farnesyl chain. Electrostatic interactions have been envisaged as the primary determinant of interactions between KRAS and membranes. Here, we integrated molecular dynamics (MD) simulations and superresolution spatial analysis in mammalian cells and systematically compared four equally charged KRAS anchors: the wild-type farnesyl hexa-lysine and engineered mutants comprising farnesyl hexa-arginine, geranylgeranyl hexa-lysine, and geranylgeranyl hexa-arginine. MD simulations show that these equally charged KRAS mutant anchors exhibit distinct interactions and packing patterns with different phosphatidylserine (PtdSer) species, indicating that prenylated PBD-bilayer interactions extend beyond electrostatics. Similar observations were apparent in intact cells, where each anchor exhibited binding specificities for PtdSer species with distinct acyl chain compositions. Acyl chain composition determined responsiveness of the spatial organization of different PtdSer species to diverse PM perturbations, including transmembrane potential, cholesterol depletion, and PM curvature. In consequence, the spatial organization and PM binding of each KRAS anchor precisely reflected the behavior of its preferred PtdSer ligand to these same PM perturbations. Taken together these results show that small GTPase PBD-prenyl anchors, such as that of KRAS, have the capacity to encode binding specificity for specific acyl chains as well as lipid headgroups, which allow differential responses to biophysical perturbations that may have biological and signaling consequences for the anchored GTPase.
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Affiliation(s)
- Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Graduate School of Biological Sciences, MD Anderson Cancer Center and University of Texas Health Science Center, Houston, TX 77030
| | - Priyanka S Prakash
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Graduate School of Biological Sciences, MD Anderson Cancer Center and University of Texas Health Science Center, Houston, TX 77030
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030;
- Graduate School of Biological Sciences, MD Anderson Cancer Center and University of Texas Health Science Center, Houston, TX 77030
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24
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The emerging roles of OSBP-related proteins in cancer: Impacts through phosphoinositide metabolism and protein-protein interactions. Biochem Pharmacol 2021; 196:114455. [PMID: 33556339 DOI: 10.1016/j.bcp.2021.114455] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 01/04/2023]
Abstract
Oxysterol-binding protein -related proteins (ORPs) form a large family of intracellular lipid binding/transfer proteins. A number of ORPs are implicated in inter-organelle lipid transfer over membrane contacts sites, their mode of action involving in several cases the transfer of two lipids in opposite directions, termed countercurrent lipid transfer. A unifying feature appears to be the capacity to bind phosphatidylinositol polyphosphates (PIPs). These lipids are in some cases transported by ORPs from one organelle to another to drive the transfer of another lipid against its concentration gradient, while they in other cases may act as allosteric regulators of ORPs, or an ORP may introduce a PIP to an enzyme for catalysis. Dysregulation of several ORP family members is implicated in cancers, ORP3, -4, -5 and -8 being thus far the most studied examples. The most likely mechanisms underlying their associations with malignant growth are (i) impacts on PIP-mediated signaling events resulting in altered Ca2+ homeostasis, bioenergetics, cell survival, proliferation, and migration, (ii) protein-protein interactions affecting the activity of signaling factors, and (iii) modification of cellular lipid transport in a way that facilitates the proliferation of malignant cells. In this review I discuss the existing functional evidence for the involvement of ORPs in cancerous growth, discuss the findings in the light of the putative mechanisms outlined above and the possibility of employing ORPs as targets of anti-cancer therapy.
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Scaffold association factor B (SAFB) is required for expression of prenyltransferases and RAS membrane association. Proc Natl Acad Sci U S A 2020; 117:31914-31922. [PMID: 33257571 DOI: 10.1073/pnas.2005712117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Inhibiting membrane association of RAS has long been considered a rational approach to anticancer therapy, which led to the development of farnesyltransferase inhibitors (FTIs). However, FTIs proved ineffective against KRAS-driven tumors. To reveal alternative therapeutic strategies, we carried out a genome-wide CRISPR-Cas9 screen designed to identify genes required for KRAS4B membrane association. We identified five enzymes in the prenylation pathway and SAFB, a nuclear protein with both DNA and RNA binding domains. Silencing SAFB led to marked mislocalization of all RAS isoforms as well as RAP1A but not RAB7A, a pattern that phenocopied silencing FNTA, the prenyltransferase α subunit shared by farnesyltransferase and geranylgeranyltransferase type I. We found that SAFB promoted RAS membrane association by controlling FNTA expression. SAFB knockdown decreased GTP loading of RAS, abrogated alternative prenylation, and sensitized RAS-mutant cells to growth inhibition by FTI. Our work establishes the prenylation pathway as paramount in KRAS membrane association, reveals a regulator of prenyltransferase expression, and suggests that reduction in FNTA expression may enhance the efficacy of FTIs.
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Delfosse V, Bourguet W, Drin G. Structural and Functional Specialization of OSBP-Related Proteins. ACTA ACUST UNITED AC 2020. [DOI: 10.1177/2515256420946627] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Lipids are precisely distributed in the eukaryotic cell where they help to define organelle identity and function, in addition to their structural role. Once synthesized, many lipids must be delivered to other compartments by non-vesicular routes, a process that is undertaken by proteins called Lipid Transfer Proteins (LTPs). OSBP and the closely-related ORP and Osh proteins constitute a major, evolutionarily conserved family of LTPs in eukaryotes. Most of these target one or more subcellular regions, and membrane contact sites in particular, where two organelle membranes are in close proximity. It was initially thought that such proteins were strictly dedicated to sterol sensing or transport. However, over the last decade, numerous studies have revealed that these proteins have many more functions, and we have expanded our understanding of their mechanisms. In particular, many of them are lipid exchangers that exploit PI(4)P or possibly other phosphoinositide gradients to directionally transfer sterol or PS between two compartments. Importantly, these transfer activities are tightly coupled to processes such as lipid metabolism, cellular signalling and vesicular trafficking. This review describes the molecular architecture of OSBP/ORP/Osh proteins, showing how their specific structural features and internal configurations impart unique cellular functions.
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Affiliation(s)
- Vanessa Delfosse
- Centre de Biochimie Structurale, Inserm, CNRS, Univ Montpellier, Montpellier, France
| | - William Bourguet
- Centre de Biochimie Structurale, Inserm, CNRS, Univ Montpellier, Montpellier, France
| | - Guillaume Drin
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d’Azur, Valbonne, France
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Kattan WE, Hancock JF. RAS Function in cancer cells: translating membrane biology and biochemistry into new therapeutics. Biochem J 2020; 477:2893-2919. [PMID: 32797215 PMCID: PMC7891675 DOI: 10.1042/bcj20190839] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 02/07/2023]
Abstract
The three human RAS proteins are mutated and constitutively activated in ∼20% of cancers leading to cell growth and proliferation. For the past three decades, many attempts have been made to inhibit these proteins with little success. Recently; however, multiple methods have emerged to inhibit KRAS, the most prevalently mutated isoform. These methods and the underlying biology will be discussed in this review with a special focus on KRAS-plasma membrane interactions.
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Affiliation(s)
- Walaa E. Kattan
- Department of Integrative Biology and Pharmacology, McGovern Medical School University of Texas Health Science Center at Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, TX 77030, USA
| | - John F. Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School University of Texas Health Science Center at Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, TX 77030, USA
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Lipp NF, Ikhlef S, Milanini J, Drin G. Lipid Exchangers: Cellular Functions and Mechanistic Links With Phosphoinositide Metabolism. Front Cell Dev Biol 2020; 8:663. [PMID: 32793602 PMCID: PMC7385082 DOI: 10.3389/fcell.2020.00663] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/01/2020] [Indexed: 12/28/2022] Open
Abstract
Lipids are amphiphilic molecules that self-assemble to form biological membranes. Thousands of lipid species coexist in the cell and, once combined, define organelle identity. Due to recent progress in lipidomic analysis, we now know how lipid composition is finely tuned in different subcellular regions. Along with lipid synthesis, remodeling and flip-flop, lipid transfer is one of the active processes that regulates this intracellular lipid distribution. It is mediated by Lipid Transfer Proteins (LTPs) that precisely move certain lipid species across the cytosol and between the organelles. A particular subset of LTPs from three families (Sec14, PITP, OSBP/ORP/Osh) act as lipid exchangers. A striking feature of these exchangers is that they use phosphatidylinositol or phosphoinositides (PIPs) as a lipid ligand and thereby have specific links with PIP metabolism and are thus able to both control the lipid composition of cellular membranes and their signaling capacity. As a result, they play pivotal roles in cellular processes such as vesicular trafficking and signal transduction at the plasma membrane. Recent data have shown that some PIPs are used as energy by lipid exchangers to generate lipid gradients between organelles. Here we describe the importance of lipid counter-exchange in the cell, its structural basis, and presumed links with pathologies.
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Affiliation(s)
- Nicolas-Frédéric Lipp
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
| | - Souade Ikhlef
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
| | - Julie Milanini
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
| | - Guillaume Drin
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
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ORP5 and ORP8: Sterol Sensors and Phospholipid Transfer Proteins at Membrane Contact Sites? Biomolecules 2020; 10:biom10060928. [PMID: 32570981 PMCID: PMC7356933 DOI: 10.3390/biom10060928] [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: 05/15/2020] [Revised: 06/13/2020] [Accepted: 06/16/2020] [Indexed: 02/07/2023] Open
Abstract
Oxysterol binding related proteins 5 and 8 (ORP5 and ORP8) are two close homologs of the larger oxysterol binding protein (OSBP) family of sterol sensors and lipid transfer proteins (LTP). Early studies indicated these transmembrane proteins, anchored to the endoplasmic reticulum (ER), bound and sensed cholesterol and oxysterols. They were identified as important for diverse cellular functions including sterol homeostasis, vesicular trafficking, proliferation and migration. In addition, they were implicated in lipid-related diseases such as atherosclerosis and diabetes, but also cancer, although their mechanisms of action remained poorly understood. Then, alongside the increasing recognition that membrane contact sites (MCS) serve as hubs for non-vesicular lipid transfer, added to their structural similarity to other LTPs, came discoveries showing that ORP5 and 8 were in fact phospholipid transfer proteins that rather sense and exchange phosphatidylserine (PS) for phosphoinositides, including phosphatidylinositol-4-phosphate (PI(4)P) and potentially phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2). Evidence now points to their action at MCS between the ER and various organelles including the plasma membrane, lysosomes, mitochondria, and lipid droplets. Dissecting exactly how this unexpected phospholipid transfer function connects with sterol regulation in health or disease remains a challenge for future studies.
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Torres M, Rosselló CA, Fernández-García P, Lladó V, Kakhlon O, Escribá PV. The Implications for Cells of the Lipid Switches Driven by Protein-Membrane Interactions and the Development of Membrane Lipid Therapy. Int J Mol Sci 2020; 21:ijms21072322. [PMID: 32230887 PMCID: PMC7177374 DOI: 10.3390/ijms21072322] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/17/2020] [Accepted: 03/19/2020] [Indexed: 02/06/2023] Open
Abstract
The cell membrane contains a variety of receptors that interact with signaling molecules. However, agonist-receptor interactions not always activate a signaling cascade. Amphitropic membrane proteins are required for signal propagation upon ligand-induced receptor activation. These proteins localize to the plasma membrane or internal compartments; however, they are only activated by ligand-receptor complexes when both come into physical contact in membranes. These interactions enable signal propagation. Thus, signals may not propagate into the cell if peripheral proteins do not co-localize with receptors even in the presence of messengers. As the translocation of an amphitropic protein greatly depends on the membrane's lipid composition, regulation of the lipid bilayer emerges as a novel therapeutic strategy. Some of the signals controlled by proteins non-permanently bound to membranes produce dramatic changes in the cell's physiology. Indeed, changes in membrane lipids induce translocation of dozens of peripheral signaling proteins from or to the plasma membrane, which controls how cells behave. We called these changes "lipid switches", as they alter the cell's status (e.g., proliferation, differentiation, death, etc.) in response to the modulation of membrane lipids. Indeed, this discovery enables therapeutic interventions that modify the bilayer's lipids, an approach known as membrane-lipid therapy (MLT) or melitherapy.
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Affiliation(s)
- Manuel Torres
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, Ctra. de Valldemossa km 7.5, E-07122 Palma, Spain; (M.T.); (C.A.R.); (P.F.-G.); (V.L.)
- Department of R&D, Laminar Pharmaceuticals SL. ParcBit, Ed. Naorte B, E-07121 Palma, Spain
| | - Catalina Ana Rosselló
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, Ctra. de Valldemossa km 7.5, E-07122 Palma, Spain; (M.T.); (C.A.R.); (P.F.-G.); (V.L.)
- Department of R&D, Laminar Pharmaceuticals SL. ParcBit, Ed. Naorte B, E-07121 Palma, Spain
| | - Paula Fernández-García
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, Ctra. de Valldemossa km 7.5, E-07122 Palma, Spain; (M.T.); (C.A.R.); (P.F.-G.); (V.L.)
- Department of R&D, Laminar Pharmaceuticals SL. ParcBit, Ed. Naorte B, E-07121 Palma, Spain
| | - Victoria Lladó
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, Ctra. de Valldemossa km 7.5, E-07122 Palma, Spain; (M.T.); (C.A.R.); (P.F.-G.); (V.L.)
- Department of R&D, Laminar Pharmaceuticals SL. ParcBit, Ed. Naorte B, E-07121 Palma, Spain
| | - Or Kakhlon
- Department of Neurology, Hadassah-Hebrew University Medical Center, Ein Kerem, 91120 Jerusalem, Israel;
| | - Pablo Vicente Escribá
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, Ctra. de Valldemossa km 7.5, E-07122 Palma, Spain; (M.T.); (C.A.R.); (P.F.-G.); (V.L.)
- Correspondence:
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