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Chen S, Pei CX, Xu S, Li H, Liu YS, Wang Y, Jin C, Dean N, Gao XD. Rft1 catalyzes lipid-linked oligosaccharide translocation across the ER membrane. Nat Commun 2024; 15:5157. [PMID: 38886340 PMCID: PMC11182771 DOI: 10.1038/s41467-024-48999-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 05/20/2024] [Indexed: 06/20/2024] Open
Abstract
The eukaryotic asparagine (N)-linked glycan is pre-assembled as a fourteen-sugar oligosaccharide on a lipid carrier in the endoplasmic reticulum (ER). Seven sugars are first added to dolichol pyrophosphate (PP-Dol) on the cytoplasmic face of the ER, generating Man5GlcNAc2-PP-Dol (M5GN2-PP-Dol). M5GN2-PP-Dol is then flipped across the bilayer into the lumen by an ER translocator. Genetic studies identified Rft1 as the M5GN2-PP-Dol flippase in vivo but are at odds with biochemical data suggesting Rft1 is dispensable for flipping in vitro. Thus, the question of whether Rft1 plays a direct or an indirect role during M5GN2-PP-Dol translocation has been controversial for over two decades. We describe a completely reconstituted in vitro assay for M5GN2-PP-Dol translocation and demonstrate that purified Rft1 catalyzes the translocation of M5GN2-PP-Dol across the lipid bilayer. These data, combined with in vitro results demonstrating substrate selectivity and rft1∆ phenotypes, confirm the molecular identity of Rft1 as the M5GN2-PP-Dol ER flippase.
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Affiliation(s)
- Shuai Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, China
| | - Cai-Xia Pei
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Si Xu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Hanjie Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yi-Shi Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yicheng Wang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, China
| | - Cheng Jin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
| | - Neta Dean
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, USA.
| | - Xiao-Dong Gao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.
- Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, China.
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2
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Silvaroli JA, Bisunke B, Kim JY, Stayton A, Jayne LA, Martinez SA, Nguyen C, Patel PS, Vanichapol T, Verma V, Akhter J, Bolisetty S, Madhavan SM, Kuscu C, Coss CC, Zepeda-Orozco D, Parikh SV, Satoskar AA, Davidson AJ, Eason JD, Szeto HH, Pabla NS, Bajwa A. Genome-Wide CRISPR Screen Identifies Phospholipid Scramblase 3 as the Biological Target of Mitoprotective Drug SS-31. J Am Soc Nephrol 2024; 35:681-695. [PMID: 38530359 PMCID: PMC11164119 DOI: 10.1681/asn.0000000000000338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 03/12/2024] [Indexed: 03/27/2024] Open
Abstract
Key Points Szeto–Schiller-31–mediated mitoprotection is phospholipid scramblase 3–dependent. Phospholipid scramblase 3 is required for recovery after AKI. Background The synthetic tetrapeptide Szeto–Schiller (SS)-31 shows promise in alleviating mitochondrial dysfunction associated with common diseases. However, the precise pharmacological basis of its mitoprotective effects remains unknown. Methods To uncover the biological targets of SS-31, we performed a genome-scale clustered regularly interspaced short palindromic repeats screen in human kidney-2, a cell culture model where SS-31 mitigates cisplatin-associated cell death and mitochondrial dysfunction. The identified hit candidate gene was functionally validated using knockout cell lines, small interfering RNA-mediated downregulation, and tubular epithelial–specific conditional knockout mice. Biochemical interaction studies were also performed to examine the interaction of SS-31 with the identified target protein. Results Our primary screen and validation studies in hexokinase 2 and primary murine tubular epithelial cells showed that phospholipid scramblase 3 (PLSCR3), an understudied inner mitochondrial membrane protein, was essential for the protective effects of SS-31. For in vivo validation, we generated tubular epithelial–specific knockout mice and found that Plscr3 gene ablation did not influence kidney function under normal conditions or affect the severity of cisplatin and rhabdomyolysis-associated AKI. However, Plscr3 gene deletion completely abrogated the protective effects of SS-31 during cisplatin and rhabdomyolysis-associated AKI. Biochemical studies showed that SS-31 directly binds to a previously uncharacterized N -terminal domain and stimulates PLSCR3 scramblase activity. Finally, PLSCR3 protein expression was found to be increased in the kidneys of patients with AKI. Conclusions PLSCR3 was identified as the essential biological target that facilitated the mitoprotective effects of SS-31 in vitro and in vivo .
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Affiliation(s)
- Josie A. Silvaroli
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Bijay Bisunke
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Ji Young Kim
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Amanda Stayton
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Laura A. Jayne
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Shirely A. Martinez
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Christopher Nguyen
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Prisha S. Patel
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Thitinee Vanichapol
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - Vivek Verma
- Department of Medicine, University of Alabama, Birmingham, Alabama
| | - Juheb Akhter
- Department of Medicine, University of Alabama, Birmingham, Alabama
| | | | - Sethu M. Madhavan
- Division of Nephrology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Cem Kuscu
- Department of Surgery, College of Medicine, Transplant Research Institute, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Christopher C. Coss
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Diana Zepeda-Orozco
- Department of Pediatrics, The Ohio State University College of Medicine and Kidney and Urinary Tract Research Center, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio
| | - Samir V. Parikh
- Division of Nephrology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Anjali A. Satoskar
- Division of Renal and Transplant Pathology, Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Alan J. Davidson
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - James D. Eason
- Department of Surgery, College of Medicine, Transplant Research Institute, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Hazel H. Szeto
- Social Profit Network Research Lab, Menlo Park, California
| | - Navjot S. Pabla
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Amandeep Bajwa
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Surgery, College of Medicine, Transplant Research Institute, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Microbiology, Immunology, and Biochemistry; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
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3
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Kong Y, Guo P, Xu J, Li J, Wu M, Zhang Z, Wang Y, Liu X, Yang L, Liu M, Zhang H, Wang P, Zhang Z. MoMkk1 and MoAtg1 dichotomously regulating autophagy and pathogenicity through MoAtg9 phosphorylation in Magnaporthe oryzae. mBio 2024; 15:e0334423. [PMID: 38501872 PMCID: PMC11005334 DOI: 10.1128/mbio.03344-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/28/2024] [Indexed: 03/20/2024] Open
Abstract
Autophagy is a central biodegradation pathway critical in eliminating intracellular cargo to maintain cellular homeostasis and improve stress resistance. At the same time, the key component of the mitogen-activated protein kinase cascade regulating cell wall integrity signaling MoMkk1 has an essential role in the autophagy of the rice blast fungus Magnaporthe oryzae. Still, the mechanism of how MoMkk1 regulates autophagy is unclear. Interestingly, we found that MoMkk1 regulates the autophagy protein MoAtg9 through phosphorylation. MoAtg9 is a transmembrane protein subjected to phosphorylation by autophagy-related protein kinase MoAtg1. Here, we provide evidence demonstrating that MoMkk1-dependent MoAtg9 phosphorylation is required for phospholipid translocation during isolation membrane stages of autophagosome formation, an autophagic process essential for the development and pathogenicity of the fungus. In contrast, MoAtg1-dependent phosphorylation of MoAtg9 negatively regulates this process, also impacting growth and pathogenicity. Our studies are the first to demonstrate that MoAtg9 is subject to MoMkk1 regulation through protein phosphorylation and that MoMkk1 and MoAtg1 dichotomously regulate autophagy to underlie the growth and pathogenicity of M. oryzae.IMPORTANCEMagnaporthe oryzae utilizes multiple signaling pathways to promote colonization of host plants. MoMkk1, a cell wall integrity signaling kinase, plays an essential role in autophagy governed by a highly conserved autophagy kinase MoAtg1-mediated pathway. How MoMkk1 regulates autophagy in coordination with MoAtg1 remains elusive. Here, we provide evidence that MoMkk1 phosphorylates MoAtg9 to positively regulate phospholipid translocation during the isolation membrane or smaller membrane structures stage of autophagosome formation. This is in contrast to the negative regulation of MoAtg9 by MoAtg1 for the same process. Intriguingly, MoMkk1-mediated MoAtg9 phosphorylation enhances the fungal infection of rice, whereas MoAtg1-dependant MoAtg9 phosphorylation significantly attenuates it. Taken together, we revealed a novel mechanism of autophagy and virulence regulation by demonstrating the dichotomous functions of MoMkk1 and MoAtg1 in the regulation of fungal autophagy and pathogenicity.
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Affiliation(s)
- Yun Kong
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Pusheng Guo
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Jiayun Xu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Jiaxu Li
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Miao Wu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Ziqi Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Yifan Wang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Xinyu Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Leiyun Yang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Muxing Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Haifeng Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Ping Wang
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
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Wan N, Hong Z, Parson MAH, Korfhage J, Burke JE, Melia TJ, Reinisch KM. Spartin-mediated lipid transfer facilitates lipid droplet turnover. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.29.569220. [PMID: 38076959 PMCID: PMC10705495 DOI: 10.1101/2023.11.29.569220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Lipid droplets (LDs) are organelles critical for energy storage and membrane lipid homeostasis, whose number and size are carefully regulated in response to cellular conditions. The molecular mechanisms underlying lipid droplet biogenesis and degradation, however, are not well understood. The Troyer syndrome protein spartin (SPG20) supports LD delivery to autophagosomes for turnover via lipophagy. Here, we characterize spartin as a lipid transfer protein whose transfer ability is required for LD degradation. Spartin co-purifies with phospholipids and neutral lipids from cells and transfers phospholipids in vitro via its senescence domain. A senescence domain truncation that impairs lipid transfer in vitro also impairs LD turnover in cells while not affecting spartin association with either LDs or autophagosomes, supporting that spartin's lipid transfer ability is physiologically relevant. Our data indicate a role for spartin-mediated lipid transfer in LD turnover.
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Affiliation(s)
- Neng Wan
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Zhouping Hong
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Matthew A. H. Parson
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W2Y2
| | - Justin Korfhage
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - John E. Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W2Y2
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Thomas J. Melia
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Karin M. Reinisch
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
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5
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Li D, Rocha-Roa C, Schilling MA, Reinisch KM, Vanni S. Lipid scrambling is a general feature of protein insertases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555937. [PMID: 37693532 PMCID: PMC10491306 DOI: 10.1101/2023.09.01.555937] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Glycerophospholipids are synthesized primarily in the cytosolic leaflet of the endoplasmic reticulum (ER) membrane and must be equilibrated between bilayer leaflets to allow the ER and membranes derived from it to grow. Lipid equilibration is facilitated by integral membrane proteins called "scramblases". These proteins feature a hydrophilic groove allowing the polar heads of lipids to traverse the hydrophobic membrane interior, similar to a credit-card moving through a reader. Nevertheless, despite their fundamental role in membrane expansion and dynamics, the identity of most scramblases has remained elusive. Here, combining biochemical reconstitution and molecular dynamics simulations, we show that lipid scrambling is a general feature of protein insertases, integral membrane proteins which insert polypeptide chains into membranes of the ER and organelles disconnected from vesicle trafficking. Our data indicate that lipid scrambling occurs in the same hydrophilic channel through which protein insertion takes place, and that scrambling is abolished in the presence of nascent polypeptide chains. We propose that protein insertases could have a so-far overlooked role in membrane dynamics as scramblases.
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Affiliation(s)
- Dazhi Li
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | | | - Matthew A Schilling
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Karin M Reinisch
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Switzerland
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6
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Leonhardt SA, Purdy MD, Grover JR, Yang Z, Poulos S, McIntire WE, Tatham EA, Erramilli SK, Nosol K, Lai KK, Ding S, Lu M, Uchil PD, Finzi A, Rein A, Kossiakoff AA, Mothes W, Yeager M. Antiviral HIV-1 SERINC restriction factors disrupt virus membrane asymmetry. Nat Commun 2023; 14:4368. [PMID: 37474505 PMCID: PMC10359404 DOI: 10.1038/s41467-023-39262-2] [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: 11/29/2022] [Accepted: 06/06/2023] [Indexed: 07/22/2023] Open
Abstract
The host proteins SERINC3 and SERINC5 are HIV-1 restriction factors that reduce infectivity when incorporated into the viral envelope. The HIV-1 accessory protein Nef abrogates incorporation of SERINCs via binding to intracellular loop 4 (ICL4). Here, we determine cryoEM maps of full-length human SERINC3 and an ICL4 deletion construct, which reveal that hSERINC3 is comprised of two α-helical bundles connected by a ~ 40-residue, highly tilted, "crossmember" helix. The design resembles non-ATP-dependent lipid transporters. Consistently, purified hSERINCs reconstituted into proteoliposomes induce flipping of phosphatidylserine (PS), phosphatidylethanolamine and phosphatidylcholine. Furthermore, SERINC3, SERINC5 and the scramblase TMEM16F expose PS on the surface of HIV-1 and reduce infectivity, with similar results in MLV. SERINC effects in HIV-1 and MLV are counteracted by Nef and GlycoGag, respectively. Our results demonstrate that SERINCs are membrane transporters that flip lipids, resulting in a loss of membrane asymmetry that is strongly correlated with changes in Env conformation and loss of infectivity.
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Grants
- P01 AI150471 NIAID NIH HHS
- P41 GM103311 NIGMS NIH HHS
- G20 RR031199 NCRR NIH HHS
- R01 GM117372 NIGMS NIH HHS
- U54 AI170856 NIAID NIH HHS
- S10 OD018149 NIH HHS
- U24 GM129539 NIGMS NIH HHS
- S10 RR025067 NCRR NIH HHS
- This work was supported by the National Institutes of Health (NIH) grants P50 AI15046 and U54 AI170856-01 (M.Y., W.M. and A.K.K.), R01 AI154092 (M.Y.), R01 GM117372 (A.A.K.) and P01 AI150471 (W.M.)., by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research, and in part by the NIH Intramural AIDS Targeted Antiviral Program. S.D. and A.F. were supported by the CIHR grant 352417 and a Canada Research Chair. Some molecular graphics and analyses were performed with the University of California, San Francisco Chimera package. Chimera is developed by the Resource for Biocomputing, Visualization, and Informatics at the University of California, San Francisco (supported by the National Institute of General Medical Sciences Grant P41 GM103311).
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Affiliation(s)
- Susan A Leonhardt
- The Phillip and Patricia Frost Institute for Chemistry and Molecular Science, University of Miami, Coral Gables, FL, 33146, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Michael D Purdy
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
- Molecular Electron Microscopy Core, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Jonathan R Grover
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Ziwei Yang
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Sandra Poulos
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - William E McIntire
- The Phillip and Patricia Frost Institute for Chemistry and Molecular Science, University of Miami, Coral Gables, FL, 33146, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Elizabeth A Tatham
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Satchal K Erramilli
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Kamil Nosol
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Kin Kui Lai
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, P.O. Box B, Building 535, Frederick, MD, 21702, USA
| | - Shilei Ding
- Centre de Recherche du CHUM (CRCHUM), Montreal, QC, Canada
| | - Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA
- Department of Cellular and Molecular Biology, University of Texas Health Science Center, Tyler, TX, USA
| | - Pradeep D Uchil
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM (CRCHUM), Montreal, QC, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
| | - Alan Rein
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, P.O. Box B, Building 535, Frederick, MD, 21702, USA
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA.
| | - Mark Yeager
- The Phillip and Patricia Frost Institute for Chemistry and Molecular Science, University of Miami, Coral Gables, FL, 33146, USA.
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
- Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
- Department of Chemistry, University of Miami, Coral Gables, FL, 33146, USA.
- Department of Biochemistry and Molecular Biology, University of Miami, Miami, FL, 33136, USA.
- Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
- Department of Medicine, Division of Cardiovascular Medicine, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
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7
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Bryl K. Fluorescence Resonance Energy Transfer (FRET) as a Spectroscopic Ruler for the Investigation of Protein Induced Lipid Membrane Curvature: Bacteriorhodopsin and Bacteriorhodopsin Analogs in Model Lipid Membranes. APPLIED SPECTROSCOPY 2023; 77:187-199. [PMID: 36229916 DOI: 10.1177/00037028221135645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Bacteriorhodopsin (bR) is a light-driven proton pump existing in the purple membranes (PM) of Halobacterium salinarum. The effects associated with changes in proton distribution (proton gradient, membrane electric potential) play a key role in ATPase stimulation. However, how the bioenergetic modulus (bR-PM-ATPase) functions remains unclear. One can find indications that hydrophobic matching and the curvature of the lipid membrane may form a functional link between bR and ATPase. To verify whether an interaction between bR and lipids can lead to curvature of the lipid membrane, a spectroscopic ruler, that is, a fluorescence resonance energy transfer (FRET) tool, was used. The distances from fluorescent lipid probes [octadecyl rhodamine B chloride (RhB), 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI), 16-(9-anthroyloxy) palmitic acid (16AP), and hydrophobic probe 1,6-diphenyl-1,3,5-hexatriene (DPH), to the retinal chromophore of bR incorporated into phospholipid vesicles, were measured. The incorporation of retinal analogues with changed shape and/or altered electronic properties into the binding site of a bR or bR mutant were used to strengthen the feedback between the protein surrounding and chromophore. The experiments were performed with wild-type and D96N-mutated bR carrying retinal or 14-(12-,10-, 13,14-bi-) fluororetinal. As far as it is known, this is the first time that results obtained by the FRET method show that bR can induce a change in lipid structure interpreted as hydrophobically induced curving of the lipid membrane. Evidence was provided that the chromophore contributed to this effect. The extent of contribution was dependent on the chromophore structure in close vicinity to the place of its link with opsin. The implications of these findings for bR-PM-ATPase module functioning are also discussed.
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Affiliation(s)
- Krzysztof Bryl
- Department of Physics and Biophysics, 49674University of Warmia and Mazury, Olsztyn, Poland
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8
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Adlakha J, Hong Z, Li P, Reinisch KM. Structural and biochemical insights into lipid transport by VPS13 proteins. J Cell Biol 2022; 221:213104. [PMID: 35357422 PMCID: PMC8978259 DOI: 10.1083/jcb.202202030] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 12/19/2022] Open
Abstract
VPS13 proteins are proposed to function at contact sites between organelles as bridges for lipids to move directionally and in bulk between organellar membranes. VPS13s are anchored between membranes via interactions with receptors, including both peripheral and integral membrane proteins. Here we present the crystal structure of VPS13s adaptor binding domain (VAB) complexed with a Pro-X-Pro peptide recognition motif present in one such receptor, the integral membrane protein Mcp1p, and show biochemically that other Pro-X-Pro motifs bind the VAB in the same site. We further demonstrate that Mcp1p and another integral membrane protein that interacts directly with human VPS13A, XK, are scramblases. This finding supports an emerging paradigm of a partnership between bulk lipid transport proteins and scramblases. Scramblases can re-equilibrate lipids between membrane leaflets as lipids are removed from or inserted into the cytosolic leaflet of donor and acceptor organelles, respectively, in the course of protein-mediated transport.
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Affiliation(s)
- Jyoti Adlakha
- Department of Cell Biology, Yale School of Medicine, New Haven, CT.,Aligning Science Across Parkinson's Collaborative Research Network, Chevy Chase, MD
| | - Zhouping Hong
- Department of Cell Biology, Yale School of Medicine, New Haven, CT.,Aligning Science Across Parkinson's Collaborative Research Network, Chevy Chase, MD
| | - PeiQi Li
- Department of Cell Biology, Yale School of Medicine, New Haven, CT
| | - Karin M Reinisch
- Department of Cell Biology, Yale School of Medicine, New Haven, CT.,Aligning Science Across Parkinson's Collaborative Research Network, Chevy Chase, MD
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9
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Mathiassen PPM, Pomorski TG. A Fluorescence-based Assay for Measuring Phospholipid Scramblase Activity in Giant Unilamellar Vesicles. Bio Protoc 2022; 12:e4366. [PMID: 35434199 PMCID: PMC8983165 DOI: 10.21769/bioprotoc.4366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 11/09/2021] [Accepted: 03/01/2022] [Indexed: 07/28/2023] Open
Abstract
Transbilayer movement of phospholipids in biological membranes is mediated by a diverse set of lipid transporters. Among them are scramblases that facilitate rapid bi-directional movement of lipids without metabolic energy input. In this protocol, we describe the incorporation of phospholipid scramblases into giant unilamellar vesicles (GUVs) formed from scramblase-containing large unilamellar vesicles by electroformation. We also describe how to analyze their activity using membrane-impermeant sodium dithionite, to bleach symmetrically incorporated fluorescent ATTO488-conjugated phospholipids. The fluorescence-based readout allows single vesicle tracking for a large number of settled/immobilized GUVs, and provides a well-defined experimental setup to directly characterize these lipid transporters at the molecular level. Graphic abstract: Giant unilamellar vesicles (GUVs) are formed by electroformation from large unilamellar vesicles (LUVs) containing phospholipid scramblases (purple) and trace amounts of a fluorescent lipid reporter (green). The scramblase activity is analyzed by a fluorescence-based assay of single GUVs, using the membrane-impermeant quencher dithionite. Sizes not to scale. Modified from Mathiassen et al. (2021).
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Affiliation(s)
- Patricia P. M. Mathiassen
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780, Bochum, Germany
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780, Bochum, Germany
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871, Frederiksberg C, Denmark
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10
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Dai Z, Wang Q, Tang J, Wu M, Li H, Yang Y, Zhen X, Yu C. Immune-regulating bimetallic metal-organic framework nanoparticles designed for cancer immunotherapy. Biomaterials 2021; 280:121261. [PMID: 34815099 DOI: 10.1016/j.biomaterials.2021.121261] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/10/2021] [Accepted: 11/14/2021] [Indexed: 12/12/2022]
Abstract
Immunogenic cell death (ICD) is a promising strategy in cancer immunotherapy to induce high immunogenicity and activate the immune system. However, its efficacy is counteracted by the concurrent exposure of phosphatidylserine (PS), an immunosuppressive signal on the surface of cancer cells. Here we report the synthesis of a bimetallic metal-organic framework (MOF) nanoparticle containing Gd3+ and Zn2+ (Gd-MOF-5) that can be used as an immunomodulator to downregulate the immunosuppressive PS signal and an ICD inducer to upregulate immunostimulatory signals. Gd3+ inhibits PS externalization via inhibiting the activity of scramblase, an enzyme to transfer PS to the outer leaflet of plasma membrane. Moreover, intracellular Zn2+ overload activates endoplasmic reticulum stress for ICD induction. In combination with an immune checkpoint inhibitor (PD-L1 antibody, denoted as aPDL1), Gd-MOF-5 activated potent immune response and effectively inhibited primary and distal tumor growth in a bilateral 4T1 tumor model. This work presents a new strategy using designed MOF materials to modulate the cell signalling and immunosuppressive microenvironment to improve the outcome of cancer immunotherapy.
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Affiliation(s)
- Zan Dai
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
| | - Qiaoyun Wang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
| | - Jie Tang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
| | - Min Wu
- MOE Key Laboratory of High Performance Polymer Materials and Technology, Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210093, PR China
| | - Haoze Li
- MOE Key Laboratory of High Performance Polymer Materials and Technology, Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210093, PR China
| | - Yannan Yang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
| | - Xu Zhen
- MOE Key Laboratory of High Performance Polymer Materials and Technology, Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210093, PR China.
| | - Chengzhong Yu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia; School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, PR China.
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11
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Straub MS, Alvadia C, Sawicka M, Dutzler R. Cryo-EM structures of the caspase-activated protein XKR9 involved in apoptotic lipid scrambling. eLife 2021; 10:e69800. [PMID: 34263724 PMCID: PMC8298096 DOI: 10.7554/elife.69800] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/11/2021] [Indexed: 12/17/2022] Open
Abstract
The exposure of the negatively charged lipid phosphatidylserine on the cell surface, catalyzed by lipid scramblases, is an important signal for the clearance of apoptotic cells by macrophages. The protein XKR9 is a member of a conserved family that has been associated with apoptotic lipid scrambling. Here, we describe structures of full-length and caspase-treated XKR9 from Rattus norvegicus in complex with a synthetic nanobody determined by cryo-electron microscopy. The 43 kDa monomeric membrane protein can be divided into two structurally related repeats, each containing four membrane-spanning segments and a helix that is partly inserted into the lipid bilayer. In the full-length protein, the C-terminus interacts with a hydrophobic pocket located at the intracellular side acting as an inhibitor of protein function. Cleavage by caspase-3 at a specific site releases 16 residues of the C-terminus, thus making the pocket accessible to the cytoplasm. Collectively, the work has revealed the unknown architecture of the XKR family and has provided initial insight into its activation by caspases.
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Affiliation(s)
- Monique S Straub
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Carolina Alvadia
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Marta Sawicka
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Raimund Dutzler
- Department of Biochemistry, University of ZurichZurichSwitzerland
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12
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Morzy D, Rubio-Sánchez R, Joshi H, Aksimentiev A, Di Michele L, Keyser UF. Cations Regulate Membrane Attachment and Functionality of DNA Nanostructures. J Am Chem Soc 2021; 143:7358-7367. [PMID: 33961742 PMCID: PMC8154537 DOI: 10.1021/jacs.1c00166] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
The interplay between nucleic acids
and lipids underpins several
key processes in molecular biology, synthetic biotechnology, vaccine
technology, and nanomedicine. These interactions are often electrostatic
in nature, and much of their rich phenomenology remains unexplored
in view of the chemical diversity of lipids, the heterogeneity of
their phases, and the broad range of relevant solvent conditions.
Here we unravel the electrostatic interactions between zwitterionic
lipid membranes and DNA nanostructures in the presence of physiologically
relevant cations, with the purpose of identifying new routes to program
DNA–lipid complexation and membrane-active nanodevices. We
demonstrate that this interplay is influenced by both the phase of
the lipid membranes and the valency of the ions and observe divalent
cation bridging between nucleic acids and gel-phase bilayers. Furthermore,
even in the presence of hydrophobic modifications on the DNA, we find
that cations are still required to enable DNA adhesion to liquid-phase
membranes. We show that the latter mechanism can be exploited to control
the degree of attachment of cholesterol-modified DNA nanostructures
by modifying their overall hydrophobicity and charge. Besides their
biological relevance, the interaction mechanisms we explored hold
great practical potential in the design of biomimetic nanodevices,
as we show by constructing an ion-regulated DNA-based synthetic enzyme.
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Affiliation(s)
- Diana Morzy
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Roger Rubio-Sánchez
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Himanshu Joshi
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States
| | - Aleksei Aksimentiev
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Lorenzo Di Michele
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom.,Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, United Kingdom
| | - Ulrich F Keyser
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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13
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Haase S, Condron M, Miller D, Cherkaoui D, Jordan S, Gulbis JM, Baum J. Identification and characterisation of a phospholipid scramblase in the malaria parasite Plasmodium falciparum. Mol Biochem Parasitol 2021; 243:111374. [PMID: 33974939 PMCID: PMC8202325 DOI: 10.1016/j.molbiopara.2021.111374] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/27/2021] [Accepted: 05/06/2021] [Indexed: 02/07/2023]
Abstract
Recent studies highlight the emerging role of lipids as important messengers in malaria parasite biology. In an attempt to identify interacting proteins and regulators of these dynamic and versatile molecules, we hypothesised the involvement of phospholipid translocases and their substrates in the infection of the host erythrocyte by the malaria parasite Plasmodium spp. Here, using a data base searching approach of the Plasmodium Genomics Resources (www.plasmodb.org), we have identified a putative phospholipid (PL) scramblase in P. falciparum (PfPLSCR) that is conserved across the genus and in closely related unicellular algae. By reconstituting recombinant PfPLSCR into liposomes, we demonstrate metal ion dependent PL translocase activity and substrate preference, confirming PfPLSCR as a bona fide scramblase. We show that PfPLSCR is expressed during asexual and sexual parasite development, localising to different membranous compartments of the parasite throughout the intra-erythrocytic life cycle. Two different gene knockout approaches, however, suggest that PfPLSCR is not essential for erythrocyte invasion and asexual parasite development, pointing towards a possible role in other stages of the parasite life cycle.
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Affiliation(s)
- Silvia Haase
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK.
| | - Melanie Condron
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - David Miller
- Division of Structural Biology, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - Dounia Cherkaoui
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Sarah Jordan
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Jacqueline M Gulbis
- Division of Structural Biology, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jake Baum
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK.
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14
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A model for a partnership of lipid transfer proteins and scramblases in membrane expansion and organelle biogenesis. Proc Natl Acad Sci U S A 2021; 118:2101562118. [PMID: 33850023 PMCID: PMC8072408 DOI: 10.1073/pnas.2101562118] [Citation(s) in RCA: 121] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The autophagy protein ATG2, proposed to transfer bulk lipid from the endoplasmic reticulum (ER) during autophagosome biogenesis, interacts with ER residents TMEM41B and VMP1 and with ATG9, in Golgi-derived vesicles that initiate autophagosome formation. In vitro assays reveal TMEM41B, VMP1, and ATG9 as scramblases. We propose a model wherein membrane expansion results from the partnership of a lipid transfer protein, moving lipids between the cytosolic leaflets of apposed organelles, and scramblases that reequilibrate the leaflets of donor and acceptor organelle membranes as lipids are depleted or augmented. TMEM41B and VMP1 are implicated broadly in lipid homeostasis and membrane dynamics processes in which their scrambling activities likely are key.
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15
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Matoba K, Kotani T, Tsutsumi A, Tsuji T, Mori T, Noshiro D, Sugita Y, Nomura N, Iwata S, Ohsumi Y, Fujimoto T, Nakatogawa H, Kikkawa M, Noda NN. Atg9 is a lipid scramblase that mediates autophagosomal membrane expansion. Nat Struct Mol Biol 2020; 27:1185-1193. [PMID: 33106658 DOI: 10.1038/s41594-020-00518-w] [Citation(s) in RCA: 232] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/15/2020] [Indexed: 12/15/2022]
Abstract
The molecular function of Atg9, the sole transmembrane protein in the autophagosome-forming machinery, remains unknown. Atg9 colocalizes with Atg2 at the expanding edge of the isolation membrane (IM), where Atg2 receives phospholipids from the endoplasmic reticulum (ER). Here we report that yeast and human Atg9 are lipid scramblases that translocate phospholipids between outer and inner leaflets of liposomes in vitro. Cryo-EM of fission yeast Atg9 reveals a homotrimer, with two connected pores forming a path between the two membrane leaflets: one pore, located at a protomer, opens laterally to the cytoplasmic leaflet; the other, at the trimer center, traverses the membrane vertically. Mutation of residues lining the pores impaired IM expansion and autophagy activity in yeast and abolished Atg9's ability to transport phospholipids between liposome leaflets. These results suggest that phospholipids delivered by Atg2 are translocated from the cytoplasmic to the luminal leaflet by Atg9, thereby driving autophagosomal membrane expansion.
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Affiliation(s)
- Kazuaki Matoba
- Institute of Microbial Chemistry (BIKAKEN), Tokyo, Japan
| | - Tetsuya Kotani
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Akihisa Tsutsumi
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takuma Tsuji
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | | | | | - Yuji Sugita
- RIKEN Cluster for Pioneering Research, Wako, Japan
- RIKEN Center for Computational Science, Kobe, Japan
- RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Norimichi Nomura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - So Iwata
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- RIKEN SPring-8 Center, Hyogo, Japan
| | - Yoshinori Ohsumi
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Toyoshi Fujimoto
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hitoshi Nakatogawa
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Masahide Kikkawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Nobuo N Noda
- Institute of Microbial Chemistry (BIKAKEN), Tokyo, Japan.
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16
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Loschwitz J, Olubiyi OO, Hub JS, Strodel B, Poojari CS. Computer simulations of protein-membrane systems. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 170:273-403. [PMID: 32145948 PMCID: PMC7109768 DOI: 10.1016/bs.pmbts.2020.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The interactions between proteins and membranes play critical roles in signal transduction, cell motility, and transport, and they are involved in many types of diseases. Molecular dynamics (MD) simulations have greatly contributed to our understanding of protein-membrane interactions, promoted by a dramatic development of MD-related software, increasingly accurate force fields, and available computer power. In this chapter, we present available methods for studying protein-membrane systems with MD simulations, including an overview about the various all-atom and coarse-grained force fields for lipids, and useful software for membrane simulation setup and analysis. A large set of case studies is discussed.
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Affiliation(s)
- Jennifer Loschwitz
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany; Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
| | - Olujide O Olubiyi
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Jochen S Hub
- Theoretical Physics and Center for Biophysics, Saarland University, Saarbrücken, Germany
| | - Birgit Strodel
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany; Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
| | - Chetan S Poojari
- Theoretical Physics and Center for Biophysics, Saarland University, Saarbrücken, Germany.
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17
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Kalienkova V, Clerico Mosina V, Bryner L, Oostergetel GT, Dutzler R, Paulino C. Stepwise activation mechanism of the scramblase nhTMEM16 revealed by cryo-EM. eLife 2019; 8:e44364. [PMID: 30785398 PMCID: PMC6414200 DOI: 10.7554/elife.44364] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 02/08/2019] [Indexed: 12/26/2022] Open
Abstract
Scramblases catalyze the movement of lipids between both leaflets of a bilayer. Whereas the X-ray structure of the protein nhTMEM16 has previously revealed the architecture of a Ca2+-dependent lipid scramblase, its regulation mechanism has remained elusive. Here, we have used cryo-electron microscopy and functional assays to address this question. Ca2+-bound and Ca2+-free conformations of nhTMEM16 in detergent and lipid nanodiscs illustrate the interactions with its environment and they reveal the conformational changes underlying its activation. In this process, Ca2+ binding induces a stepwise transition of the catalytic subunit cavity, converting a closed cavity that is shielded from the membrane in the absence of ligand, into a polar furrow that becomes accessible to lipid headgroups in the Ca2+-bound state. Additionally, our structures demonstrate how nhTMEM16 distorts the membrane at both entrances of the subunit cavity, thereby decreasing the energy barrier for lipid movement.
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Affiliation(s)
| | - Vanessa Clerico Mosina
- Department of Structural Biology, Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenGroningenThe Netherlands
| | - Laura Bryner
- Department of BiochemistryUniversity of ZurichZurichSwitzerland
| | - Gert T Oostergetel
- Department of Structural Biology, Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenGroningenThe Netherlands
| | - Raimund Dutzler
- Department of BiochemistryUniversity of ZurichZurichSwitzerland
| | - Cristina Paulino
- Department of Structural Biology, Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenGroningenThe Netherlands
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18
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Alvadia C, Lim NK, Clerico Mosina V, Oostergetel GT, Dutzler R, Paulino C. Cryo-EM structures and functional characterization of the murine lipid scramblase TMEM16F. eLife 2019; 8:e44365. [PMID: 30785399 PMCID: PMC6414204 DOI: 10.7554/elife.44365] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 02/19/2019] [Indexed: 12/13/2022] Open
Abstract
The lipid scramblase TMEM16F initiates blood coagulation by catalyzing the exposure of phosphatidylserine in platelets. The protein is part of a family of membrane proteins, which encompasses calcium-activated channels for ions and lipids. Here, we reveal features of murine TMEM16F (mTMEM16F) that underlie its function as a lipid scramblase and an ion channel. The cryo-EM data of mTMEM16F in absence and presence of Ca2+ define the ligand-free closed conformation of the protein and the structure of a Ca2+-bound intermediate. Both conformations resemble their counterparts of the scrambling-incompetent anion channel mTMEM16A, yet with distinct differences in the region of ion and lipid permeation. In conjunction with functional data, we demonstrate the relationship between ion conduction and lipid scrambling. Although activated by a common mechanism, both functions appear to be mediated by alternate protein conformations that are at equilibrium in the ligand-bound state.
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Affiliation(s)
| | - Novandy K Lim
- Department of BiochemistryUniversity of ZurichZurichSwitzerland
| | - Vanessa Clerico Mosina
- Department of Structural Biology at the Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenGroningenNetherlands
| | - Gert T Oostergetel
- Department of Structural Biology at the Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenGroningenNetherlands
| | - Raimund Dutzler
- Department of BiochemistryUniversity of ZurichZurichSwitzerland
| | - Cristina Paulino
- Department of Structural Biology at the Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenGroningenNetherlands
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19
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Brunner JD, Schenck S. Preparation of Proteoliposomes with Purified TMEM16 Protein for Accurate Measures of Lipid Scramblase Activity. Methods Mol Biol 2019; 1949:181-199. [PMID: 30790257 DOI: 10.1007/978-1-4939-9136-5_14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The distribution of different lipid species between the two leaflets is tightly regulated and underlies the concerted action of distinct catalytic entities. While flippases and floppases establish membrane asymmetry, scramblases randomize the lipid distribution and play pivotal roles during blood clotting, apoptosis, and in processes such as N-linked glycosylation of proteins. The recent discovery of TMEM16 family members acting as scramblases has led to an increasing demand for developing protocols tailored for TMEM16 proteins to enable functional investigations of their scrambling activity. Here we describe a protocol for the expression, purification, and functional reconstitution of TMEM16 proteins into preformed liposomes and measurement of their scrambling activity using fluorescence-labeled lipid derivatives. The reconstitution involves extrusion of liposomes through a membrane, destabilization of liposomes using Triton X-100, and stepwise detergent removal by adsorption on styryl-beads. The scrambling assay is based on the selective bleaching of nitrobenzoxadiazol fluorescent lipids on the outer leaflet of liposomes by the membrane-impermeant reducing agent sodium dithionite. The assay allows conclusions on the substrate specificity and on the kinetics of the transported lipids as shown with the example of a Ca2+-activated TMEM16 scramblase from the fungus Nectria haematococca (nhTMEM16).
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Affiliation(s)
- Janine Denise Brunner
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, Switzerland.
| | - Stephan Schenck
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, Switzerland
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20
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Wang L, Iwasaki Y, Andra KK, Pandey K, Menon AK, Bütikofer P. Scrambling of natural and fluorescently tagged phosphatidylinositol by reconstituted G protein-coupled receptor and TMEM16 scramblases. J Biol Chem 2018; 293:18318-18327. [PMID: 30287690 PMCID: PMC6254352 DOI: 10.1074/jbc.ra118.004213] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 10/03/2018] [Indexed: 12/12/2022] Open
Abstract
Members of the G protein-coupled receptor and TMEM16 (transmembrane protein 16) protein families are phospholipid scramblases that facilitate rapid, bidirectional movement of phospholipids across a membrane bilayer in an ATP-independent manner. On reconstitution into large unilamellar vesicles, these proteins scramble more than 10,000 lipids/protein/s as measured with co-reconstituted fluorescent nitrobenzoxadiazole (NBD)-labeled phospholipids. Although NBD-labeled phospholipids are ubiquitously used as reporters of scramblase activity, it remains unclear whether the NBD modification influences the quantitative outcomes of the scramblase assay. We now report a refined biochemical approach for measuring the activity of scramblase proteins with radiolabeled natural phosphatidylinositol ([3H]PI) and exploiting the hydrolytic activity of bacterial PI-specific phospholipase C (PI-PLC) to detect the transbilayer movement of PI. PI-PLC rapidly hydrolyzed 50% of [3H]PI in large symmetric, unilamellar liposomes, corresponding to the lipid pool in the outer leaflet. On reconstitution of a crude preparation of yeast endoplasmic reticulum scramblase, purified bovine opsin, or purified Nectria haematococca TMEM16, the extent of [3H]PI hydrolysis increased, indicating that [3H]PI from the inner leaflet had been scrambled to the outer leaflet. Using transphosphatidylation, we synthesized acyl-NBD-PI and used it to compare our PI-PLC-based assay with conventional fluorescence-based methods. Our results revealed quantitative differences between the two assays that we attribute to the specific features of the assays themselves rather than to the nature of the phospholipid. In summary, we have developed an assay that measures scrambling of a chemically unmodified phospholipid by a reconstituted scramblase.
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Affiliation(s)
- Lei Wang
- From the Institute of Biochemistry and Molecular Medicine and; Graduate School for Cellular and Biochemical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Yugo Iwasaki
- the Laboratory of Molecular Biotechnology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Nagoya 464-8601, Japan, and
| | - Kiran K Andra
- the Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065
| | - Kalpana Pandey
- the Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065
| | - Anant K Menon
- the Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065.
| | - Peter Bütikofer
- From the Institute of Biochemistry and Molecular Medicine and.
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21
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Malvezzi M, Andra KK, Pandey K, Lee BC, Falzone ME, Brown A, Iqbal R, Menon AK, Accardi A. Out-of-the-groove transport of lipids by TMEM16 and GPCR scramblases. Proc Natl Acad Sci U S A 2018; 115:E7033-E7042. [PMID: 29925604 PMCID: PMC6065010 DOI: 10.1073/pnas.1806721115] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Phospholipid scramblases externalize phosphatidylserine to facilitate numerous physiological processes. Several members of the structurally unrelated TMEM16 and G protein-coupled receptor (GPCR) protein families mediate phospholipid scrambling. The structure of a TMEM16 scramblase shows a membrane-exposed hydrophilic cavity, suggesting that scrambling occurs via the ‟credit-card" mechanism where lipid headgroups permeate through the cavity while their tails remain associated with the membrane core. Here we show that afTMEM16 and opsin, representatives of the TMEM16 and GCPR scramblase families, transport phospholipids with polyethylene glycol headgroups whose globular dimensions are much larger than the width of the cavity. This suggests that transport of these large headgroups occurs outside rather than within the cavity. These large lipids are scrambled at rates comparable to those of normal phospholipids and their presence in the reconstituted vesicles promotes scrambling of normal phospholipids. This suggests that both large and small phospholipids can move outside the cavity. We propose that the conformational rearrangements underlying TMEM16- and GPCR-mediated credit-card scrambling locally deform the membrane to allow transbilayer lipid translocation outside the cavity and that both mechanisms underlie transport of normal phospholipids.
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Affiliation(s)
- Mattia Malvezzi
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY 10065
| | - Kiran K Andra
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | - Kalpana Pandey
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | - Byoung-Cheol Lee
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY 10065
| | - Maria E Falzone
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | - Ashley Brown
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | - Rabia Iqbal
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | - Anant K Menon
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | - Alessio Accardi
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY 10065;
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065
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22
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Mechanisms of Lipid Scrambling by the G Protein-Coupled Receptor Opsin. Structure 2017; 26:356-367.e3. [PMID: 29290486 DOI: 10.1016/j.str.2017.11.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/29/2017] [Accepted: 11/27/2017] [Indexed: 01/05/2023]
Abstract
Several class-A G protein-coupled receptor (GPCR) proteins act as constitutive phospholipid scramblases catalyzing the transbilayer translocation of >10,000 phospholipids per second when reconstituted into synthetic vesicles. To address the molecular mechanism by which these proteins facilitate rapid lipid scrambling, we carried out large-scale ensemble atomistic molecular dynamics simulations of the opsin GPCR. We report that, in the process of scrambling, lipid head groups traverse a dynamically revealed hydrophilic pathway in the region between transmembrane helices 6 and 7 of the protein while their hydrophobic tails remain in the bilayer environment. We present quantitative kinetic models of the translocation process based on Markov State Model analysis. As key residues on the lipid translocation pathway are conserved within the class-A GPCR family, our results illuminate unique aspects of GPCR structure and dynamics while providing a rigorous basis for the design of variants of these proteins with defined scramblase activity.
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23
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Pandey K, Ploier B, Goren MA, Levitz J, Khelashvili G, Menon AK. An engineered opsin monomer scrambles phospholipids. Sci Rep 2017; 7:16741. [PMID: 29196630 PMCID: PMC5711885 DOI: 10.1038/s41598-017-16842-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/16/2017] [Indexed: 11/09/2022] Open
Abstract
The G protein-coupled receptor opsin is a phospholipid scramblase that facilitates rapid transbilayer phospholipid exchange in liposomes. The mechanism by which opsin scrambles lipids is unknown. It has been proposed that lipid translocation may occur at protein-protein interfaces of opsin dimers. To test this possibility, we rationally engineered QUAD opsin by tryptophan substitution of four lipid-facing residues in transmembrane helix 4 (TM4) that is known to be important for dimerization. Atomistic molecular dynamics simulations of wild type and QUAD opsins combined with continuum modeling revealed that the tryptophan substitutions lower the energetically unfavorable residual hydrophobic mismatch between TM4 and the membrane, reducing the drive of QUAD opsin to dimerize. We purified thermostable wild type and QUAD opsins, with or without a SNAP tag for fluorescence labeling. Single molecule fluorescence measurements of purified SNAP-tagged constructs revealed that both proteins are monomers. Fluorescence-based activity assays indicated that QUAD opsin is a fully functional scramblase. However, unlike wild type opsin which dimerizes en route to insertion into phospholipid vesicles, QUAD opsin reconstitutes as a monomer. We conclude that an engineered opsin monomer can scramble phospholipids, and that the lipid-exposed face of TM4 is unlikely to contribute to transbilayer phospholipid exchange.
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Affiliation(s)
- Kalpana Pandey
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA
| | - Birgit Ploier
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA
| | - Michael A Goren
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA
| | - George Khelashvili
- Department of Physiology and Biophysics, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA.,Institute for Computational Biomedicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA
| | - Anant K Menon
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA.
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24
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Verchère A, Ou WL, Ploier B, Morizumi T, Goren MA, Bütikofer P, Ernst OP, Khelashvili G, Menon AK. Light-independent phospholipid scramblase activity of bacteriorhodopsin from Halobacterium salinarum. Sci Rep 2017; 7:9522. [PMID: 28842688 PMCID: PMC5572738 DOI: 10.1038/s41598-017-09835-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/31/2017] [Indexed: 12/11/2022] Open
Abstract
The retinylidene protein bacteriorhodopsin (BR) is a heptahelical light-dependent proton pump found in the purple membrane of the archaeon Halobacterium salinarum. We now show that when reconstituted into large unilamellar vesicles, purified BR trimers exhibit light-independent lipid scramblase activity, thereby facilitating transbilayer exchange of phospholipids between the leaflets of the vesicle membrane at a rate >10,000 per trimer per second. This activity is comparable to that of recently described scramblases including bovine rhodopsin and fungal TMEM16 proteins. Specificity tests reveal that BR scrambles fluorescent analogues of common phospholipids but does not transport a glycosylated diphosphate isoprenoid lipid. In silico analyses suggest that membrane-exposed polar residues in transmembrane helices 1 and 2 of BR may provide the molecular basis for lipid translocation by coordinating the polar head-groups of transiting phospholipids. Consistent with this possibility, extensive coarse-grained molecular dynamics simulations of a BR trimer in an explicit phospholipid membrane revealed water penetration along transmembrane helix 1 with the cooperation of a polar residue (Y147 in transmembrane helix 5) in the adjacent protomer. These results suggest that the lipid translocation pathway may lie at or near the interface of the protomers of a BR trimer.
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Affiliation(s)
- Alice Verchère
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, New York, 10065, USA
| | - Wei-Lin Ou
- Department of Biochemistry, University of Toronto, 1 Kings College Circle, Toronto, Ontario, Canada, M5S 1A8
| | - Birgit Ploier
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, New York, 10065, USA
| | - Takefumi Morizumi
- Department of Biochemistry, University of Toronto, 1 Kings College Circle, Toronto, Ontario, Canada, M5S 1A8
| | - Michael A Goren
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, New York, 10065, USA
| | - Peter Bütikofer
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012, Bern, Switzerland
| | - Oliver P Ernst
- Department of Biochemistry, University of Toronto, 1 Kings College Circle, Toronto, Ontario, Canada, M5S 1A8.,Department of Molecular Genetics, University of Toronto, 1 Kings College Circle, Toronto, Ontario, Canada, M5S 1A8
| | - George Khelashvili
- Department of Physiology and Biophysics, and Institute for Computational Biomedicine, Weill Cornell Medical College, 1300 York Avenue, New York, New York, 10065, USA
| | - Anant K Menon
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, New York, 10065, USA.
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