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Rahimian S, Najafi H, Webber CA, Jalali H. Advances in Exosome-Based Therapies for the Repair of Peripheral Nerve Injuries. Neurochem Res 2024; 49:1905-1925. [PMID: 38807021 DOI: 10.1007/s11064-024-04157-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 03/07/2024] [Accepted: 05/17/2024] [Indexed: 05/30/2024]
Abstract
Peripheral nerve injuries (PNIs) are the term used to describe injuries that occur to the nerve fibers of the peripheral nervous system (PNS). Such injuries may be caused by trauma, infection, or aberrant immunological response. Although the peripheral nervous system has a limited capacity for self-repair, in cases of severe damage, this process is either interrupted entirely or is only partially completed. The evaluation of variables that promote the repair of peripheral nerves has consistently been a focal point. Exosomes are a subtype of extracellular vesicles that originate from cellular sources and possess abundant proteins, lipids, and nucleic acids, play a critical role in facilitating intercellular communication. Due to their modifiable composition, they possess exceptional capabilities as carriers for therapeutic compounds, including but not limited to mRNAs or microRNAs. Exosome-based therapies have gained significant attention in the treatment of several nervous system diseases due to their advantageous properties, such as low toxicity, high stability, and limited immune system activation. The objective of this review article is to provide an overview of exosome-based treatments that have been developed in recent years for a range of PNIs, including nerve trauma, diabetic neuropathy, amyotrophic lateral sclerosis (ALS), glaucoma, and Guillain-Barre syndrome (GBS). It was concluded that exosomes could provide favorable results in the improvement of peripheral PNIs by facilitating the transfer of regenerative factors. The development of bioengineered exosome therapy for PNIs should be given more attention to enhance the efficacy of exosome treatment for PNIs.
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Affiliation(s)
- Sana Rahimian
- Division of Nanobiotehnology, Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Hossein Najafi
- Division of Nanobiotehnology, Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Christine A Webber
- Division of Anatomy, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Hanieh Jalali
- Division of Cell and Developmental Biology, Department of Animal Biology, Faculty of Biological Sciences, Kharazmi University, No. 43, South Moffateh Ave, Tehran, 15719-14911, Iran.
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2
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Ma M, Ganapathi M, Zheng Y, Tan KL, Kanca O, Bove KE, Quintanilla N, Sag SO, Temel SG, LeDuc CA, McPartland AJ, Pereira EM, Shen Y, Hagen J, Thomas CP, Nguyen Galván NT, Pan X, Lu S, Rosenfeld JA, Calame DG, Wangler MF, Lupski JR, Pehlivan D, Hertel PM, Chung WK, Bellen HJ. Homozygous missense variants in YKT6 result in loss of function and are associated with developmental delay, with or without severe infantile liver disease and risk for hepatocellular carcinoma. Genet Med 2024; 26:101125. [PMID: 38522068 PMCID: PMC11335040 DOI: 10.1016/j.gim.2024.101125] [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: 09/21/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 03/26/2024] Open
Abstract
PURPOSE YKT6 plays important roles in multiple intracellular vesicle trafficking events but has not been associated with Mendelian diseases. METHODS We report 3 unrelated individuals with rare homozygous missense variants in YKT6 who exhibited neurological disease with or without a progressive infantile liver disease. We modeled the variants in Drosophila. We generated wild-type and variant genomic rescue constructs of the fly ortholog dYkt6 and compared their ability in rescuing the loss-of-function phenotypes in mutant flies. We also generated a dYkt6KozakGAL4 allele to assess the expression pattern of dYkt6. RESULTS Two individuals are homozygous for YKT6 [NM_006555.3:c.554A>G p.(Tyr185Cys)] and exhibited normal prenatal course followed by failure to thrive, developmental delay, and progressive liver disease. Haplotype analysis identified a shared homozygous region flanking the variant, suggesting a common ancestry. The third individual is homozygous for YKT6 [NM_006555.3:c.191A>G p.(Tyr64Cys)] and exhibited neurodevelopmental disorders and optic atrophy. Fly dYkt6 is essential and is expressed in the fat body (analogous to liver) and central nervous system. Wild-type genomic rescue constructs can rescue the lethality and autophagic flux defects, whereas the variants are less efficient in rescuing the phenotypes. CONCLUSION The YKT6 variants are partial loss-of-function alleles, and the p.(Tyr185Cys) is more severe than p.(Tyr64Cys).
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Affiliation(s)
- Mengqi Ma
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX
| | - Mythily Ganapathi
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY
| | - Yiming Zheng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX
| | - Kai-Li Tan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX
| | - Kevin E Bove
- Department of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Norma Quintanilla
- Department of Pathology and Immunology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX
| | - Sebnem O Sag
- Department of Medical Genetics, Faculty of Medicine, Uludag University, Bursa, Turkey
| | - Sehime G Temel
- Department of Medical Genetics, Faculty of Medicine, Uludag University, Bursa, Turkey
| | | | | | | | - Yufeng Shen
- Department of Systems Biology, Columbia University Medical Center, New York, NY
| | - Jacob Hagen
- Department of Systems Biology, Columbia University Medical Center, New York, NY
| | - Christie P Thomas
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA
| | | | - Xueyang Pan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX
| | - Shenzhao Lu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Baylor Genetics Laboratories, Houston, TX
| | - Daniel G Calame
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Division of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX; Texas Children's Hospital, Houston, TX
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Texas Children's Hospital, Houston, TX; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX; Division of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX; Texas Children's Hospital, Houston, TX
| | - Paula M Hertel
- Texas Children's Hospital, Houston, TX; Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Wendy K Chung
- Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA.
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX.
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3
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Yuan Y, Li P, Li J, Zhao Q, Chang Y, He X. Protein lipidation in health and disease: molecular basis, physiological function and pathological implication. Signal Transduct Target Ther 2024; 9:60. [PMID: 38485938 PMCID: PMC10940682 DOI: 10.1038/s41392-024-01759-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/31/2023] [Accepted: 01/24/2024] [Indexed: 03/18/2024] Open
Abstract
Posttranslational modifications increase the complexity and functional diversity of proteins in response to complex external stimuli and internal changes. Among these, protein lipidations which refer to lipid attachment to proteins are prominent, which primarily encompassing five types including S-palmitoylation, N-myristoylation, S-prenylation, glycosylphosphatidylinositol (GPI) anchor and cholesterylation. Lipid attachment to proteins plays an essential role in the regulation of protein trafficking, localisation, stability, conformation, interactions and signal transduction by enhancing hydrophobicity. Accumulating evidence from genetic, structural, and biomedical studies has consistently shown that protein lipidation is pivotal in the regulation of broad physiological functions and is inextricably linked to a variety of diseases. Decades of dedicated research have driven the development of a wide range of drugs targeting protein lipidation, and several agents have been developed and tested in preclinical and clinical studies, some of which, such as asciminib and lonafarnib are FDA-approved for therapeutic use, indicating that targeting protein lipidations represents a promising therapeutic strategy. Here, we comprehensively review the known regulatory enzymes and catalytic mechanisms of various protein lipidation types, outline the impact of protein lipidations on physiology and disease, and highlight potential therapeutic targets and clinical research progress, aiming to provide a comprehensive reference for future protein lipidation research.
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Affiliation(s)
- Yuan Yuan
- Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Peiyuan Li
- Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jianghui Li
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China
- Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, China
| | - Qiu Zhao
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China.
- Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, China.
| | - Ying Chang
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China.
- Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, China.
| | - Xingxing He
- Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China.
- Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, China.
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4
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Szenci G, Glatz G, Takáts S, Juhász G. The Ykt6-Snap29-Syx13 SNARE complex promotes crinophagy via secretory granule fusion with Lamp1 carrier vesicles. Sci Rep 2024; 14:3200. [PMID: 38331993 PMCID: PMC10853563 DOI: 10.1038/s41598-024-53607-x] [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: 12/14/2023] [Accepted: 02/02/2024] [Indexed: 02/10/2024] Open
Abstract
In the Drosophila larval salivary gland, developmentally programmed fusions between lysosomes and secretory granules (SGs) and their subsequent acidification promote the maturation of SGs that are secreted shortly before puparium formation. Subsequently, ongoing fusions between non-secreted SGs and lysosomes give rise to degradative crinosomes, where the superfluous secretory material is degraded. Lysosomal fusions control both the quality and quantity of SGs, however, its molecular mechanism is incompletely characterized. Here we identify the R-SNARE Ykt6 as a novel regulator of crinosome formation, but not the acidification of maturing SGs. We show that Ykt6 localizes to Lamp1+ carrier vesicles, and forms a SNARE complex with Syntaxin 13 and Snap29 to mediate fusion with SGs. These Lamp1 carriers represent a distinct vesicle population that are functionally different from canonical Arl8+, Cathepsin L+ lysosomes, which also fuse with maturing SGs but are controlled by another SNARE complex composed of Syntaxin 13, Snap29 and Vamp7. Ykt6- and Vamp7-mediated vesicle fusions also determine the fate of SGs, as loss of either of these SNAREs prevents crinosomes from acquiring endosomal PI3P. Our results highlight that fusion events between SGs and different lysosome-related vesicle populations are critical for fine regulation of the maturation and crinophagic degradation of SGs.
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Affiliation(s)
- Győző Szenci
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, 1117, Hungary
- Doctoral School of Biology, Institute of Biology, Eötvös Loránd University, Budapest, 1117, Hungary
| | - Gábor Glatz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, 1117, Hungary
| | - Szabolcs Takáts
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, 1117, Hungary.
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, 1117, Hungary.
- Institute of Genetics, HUN-REN Biological Research Centre Szeged, Szeged, 6726, Hungary.
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5
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Ji J, Yu Y, Wu S, Wang D, Weng J, Wang W. Different conformational dynamics of SNARE protein Ykt6 among yeast and mammals. J Biol Chem 2023; 299:104968. [PMID: 37380075 PMCID: PMC10388204 DOI: 10.1016/j.jbc.2023.104968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 05/29/2023] [Accepted: 06/19/2023] [Indexed: 06/30/2023] Open
Abstract
Ykt6 is one of the most conserved SNARE (N-ethylmaleimide-sensitive factor attachment protein receptor) proteins involved in multiple intracellular membrane trafficking processes. The membrane-anchoring function of Ykt6 has been elucidated to result from its conformational transition from a closed state to an open state. Two ways of regulating the conformational transition were proposed: the C-terminal lipidation and the phosphorylation at the SNARE core. Despite many aspects of common properties, Ykt6 displays differential cellular localizations and functional behaviors in different species, such as yeast, mammals, and worms. The structure-function relationship underlying these differences remains elusive. Here, we combined biochemical characterization, single-molecule FRET measurement, and molecular dynamics simulation to compare the conformational dynamics of yeast and rat Ykt6. Compared to rat Ykt6 (rYkt6), yeast Ykt6 (yYkt6) has more open conformations and could not bind dodecylphosphocholine that inhibits rYkt6 in the closed state. A point mutation T46L/Q57A was shown to be able to convert yYkt6 to a more closed and dodecylphosphocholine-bound state, where Leu46 contributes key hydrophobic interactions for the closed state. We also demonstrated that the phospho-mutation S174D could shift the conformation of rYkt6 to a more open state, but the corresponding mutation S176D in yYkt6 leads to a slightly more closed conformation. These observations shed light on the regulatory mechanism underlying the variations of Ykt6 functions across species.
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Affiliation(s)
- Jie Ji
- Department of Chemistry, Institute of Biomedical Sciences and Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China
| | - Yiping Yu
- Department of Chemistry, Institute of Biomedical Sciences and Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China
| | - Shaowen Wu
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong, China
| | | | - Jingwei Weng
- Department of Chemistry, Institute of Biomedical Sciences and Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China.
| | - Wenning Wang
- Department of Chemistry, Institute of Biomedical Sciences and Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China.
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6
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A conformational switch driven by phosphorylation regulates the activity of the evolutionarily conserved SNARE Ykt6. Proc Natl Acad Sci U S A 2021; 118:2016730118. [PMID: 33723042 PMCID: PMC8000380 DOI: 10.1073/pnas.2016730118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ykt6 is a conserved SNARE that plays critical roles along multiple vesicular pathways. To achieve its function, Ykt6 cycles between the cytosol and membrane-bound compartments through reversible lipidation. The mechanism that regulates these transitions is unknown. Ykt6 function is disrupted by α-synuclein, a protein critically implicated in synucleinopathies such as Parkinson’s Disease. Through a multidisciplinary approach, we report that phosphorylation regulated by Ca2+ signaling drives a conformational change that allows Ykt6 to switch from a closed cytosolic to an open membrane-bound form. Phosphorylation is also a critical determinant for Ykt6 protein interactions with functional consequences in the secretory and autophagy pathways under normal and α-synuclein conditions. This work provides a mechanistic insight into Ykt6 regulation with therapeutic implications for synucleinopathies. Ykt6 is a soluble N-ethylmaleimide sensitive factor activating protein receptor (SNARE) critically involved in diverse vesicular fusion pathways. While most SNAREs rely on transmembrane domains for their activity, Ykt6 dynamically cycles between the cytosol and membrane-bound compartments where it is active. The mechanism that regulates these transitions and allows Ykt6 to achieve specificity toward vesicular pathways is unknown. Using a Parkinson’s disease (PD) model, we found that Ykt6 is phosphorylated at an evolutionarily conserved site which is regulated by Ca2+ signaling. Through a multidisciplinary approach, we show that phosphorylation triggers a conformational change that allows Ykt6 to switch from a closed cytosolic to an open membrane-bound form. In the phosphorylated open form, the spectrum of protein interactions changes, leading to defects in both the secretory and autophagy pathways, enhancing toxicity in PD models. Our studies reveal a mechanism by which Ykt6 conformation and activity are regulated with potential implications for PD.
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7
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Feng Z, Shi H, Lv M, Ma Y, Li J. Protein farnesylation negatively regulates brassinosteroid signaling via reducing BES1 stability in Arabidopsis thaliana. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:1353-1366. [PMID: 33764637 PMCID: PMC8360029 DOI: 10.1111/jipb.13093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
Brassinosteroids (BRs) are a group of steroidal phytohormones, playing critical roles in almost all physiological aspects during the life span of a plant. In Arabidopsis, BRs are perceived at the cell surface, triggering a reversible phosphorylation-based signaling cascade that leads to the activation and nuclear accumulation of a family of transcription factors, represented by BES1 and BZR1. Protein farnesylation is a type of post-translational modification, functioning in many important cellular processes. Previous studies demonstrated a role of farnesylation in BR biosynthesis via regulating the endoplasmic reticulum localization of a key bassinolide (BL) biosynthetic enzyme BR6ox2. Whether such a process is also involved in BR signaling is not understood. Here, we demonstrate that protein farnesylation is involved in mediating BR signaling in Arabidopsis. A loss-of-function mutant of ENHANCED RESPONSE TO ABA 1 (ERA1), encoding a β subunit of the protein farnesyl transferase holoenzyme, can alter the BL sensitivity of bak1-4 from a reduced to a hypersensitive level. era1 can partially rescue the BR defective phenotype of a heterozygous mutant of bin2-1, a gain-of-function mutant of BIN2 which encodes a negative regulator in the BR signaling. Our genetic and biochemical analyses revealed that ERA1 plays a significant role in regulating the protein stability of BES1.
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Affiliation(s)
- Zengxiu Feng
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Hongyong Shi
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Minghui Lv
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yuang Ma
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Jia Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
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Gao J, Kurre R, Rose J, Walter S, Fröhlich F, Piehler J, Reggiori F, Ungermann C. Function of the SNARE Ykt6 on autophagosomes requires the Dsl1 complex and the Atg1 kinase complex. EMBO Rep 2020; 21:e50733. [PMID: 33025734 PMCID: PMC7726795 DOI: 10.15252/embr.202050733] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 09/04/2020] [Accepted: 09/14/2020] [Indexed: 12/11/2022] Open
Abstract
The mechanism and regulation of fusion between autophagosomes and lysosomes/vacuoles are still only partially understood in both yeast and mammals. In yeast, this fusion step requires SNARE proteins, the homotypic vacuole fusion and protein sorting (HOPS) tethering complex, the RAB7 GTPase Ypt7, and its guanine nucleotide exchange factor (GEF) Mon1‐Ccz1. We and others recently identified Ykt6 as the autophagosomal SNARE protein. However, it has not been resolved when and how lipid‐anchored Ykt6 is recruited onto autophagosomes. Here, we show that Ykt6 is recruited at an early stage of the formation of these carriers through a mechanism that depends on endoplasmic reticulum (ER)‐resident Dsl1 complex and COPII‐coated vesicles. Importantly, Ykt6 activity on autophagosomes is regulated by the Atg1 kinase complex, which inhibits Ykt6 through direct phosphorylation. Thus, our findings indicate that the Ykt6 pool on autophagosomal membranes is kept inactive by Atg1 phosphorylation, and once an autophagosome is ready to fuse with vacuole, Ykt6 dephosphorylation allows its engagement in the fusion event.
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Affiliation(s)
- Jieqiong Gao
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany
| | - Rainer Kurre
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, Osnabrück, Germany
| | - Jaqueline Rose
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany
| | - Stefan Walter
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Florian Fröhlich
- Department of Biology/Chemistry, Molecular Membrane Biology Group, University of Osnabrück, Osnabrück, Germany
| | - Jacob Piehler
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, Osnabrück, Germany.,Department of Biology/Chemistry, Biophysics Section, University of Osnabrück, Osnabrück, Germany
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
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9
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Shirakawa R, Goto‐Ito S, Goto K, Wakayama S, Kubo H, Sakata N, Trinh DA, Yamagata A, Sato Y, Masumoto H, Cheng J, Fujimoto T, Fukai S, Horiuchi H. A SNARE geranylgeranyltransferase essential for the organization of the Golgi apparatus. EMBO J 2020; 39:e104120. [PMID: 32128853 PMCID: PMC7156963 DOI: 10.15252/embj.2019104120] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/22/2020] [Accepted: 01/31/2020] [Indexed: 01/08/2023] Open
Abstract
Protein prenylation is essential for many cellular processes including signal transduction, cytoskeletal reorganization, and membrane trafficking. Here, we identify a novel type of protein prenyltransferase, which we named geranylgeranyltransferase type-III (GGTase-III). GGTase-III consists of prenyltransferase alpha subunit repeat containing 1 (PTAR1) and the β subunit of RabGGTase. Using a biotinylated geranylgeranyl analogue, we identified the Golgi SNARE protein Ykt6 as a substrate of GGTase-III. GGTase-III transfers a geranylgeranyl group to mono-farnesylated Ykt6, generating doubly prenylated Ykt6. The crystal structure of GGTase-III in complex with Ykt6 provides structural basis for Ykt6 double prenylation. In GGTase-III-deficient cells, Ykt6 remained in a singly prenylated form, and the Golgi SNARE complex assembly was severely impaired. Consequently, the Golgi apparatus was structurally disorganized, and intra-Golgi protein trafficking was delayed. Our findings reveal a fourth type of protein prenyltransferase that generates geranylgeranyl-farnesyl Ykt6. Double prenylation of Ykt6 is essential for the structural and functional organization of the Golgi apparatus.
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Affiliation(s)
- Ryutaro Shirakawa
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Sakurako Goto‐Ito
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
- Synchrotron Radiation Research OrganizationThe University of TokyoTokyoJapan
| | - Kota Goto
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Shonosuke Wakayama
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Haremaru Kubo
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Natsumi Sakata
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Duc Anh Trinh
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Atsushi Yamagata
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
- Synchrotron Radiation Research OrganizationThe University of TokyoTokyoJapan
| | - Yusuke Sato
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
- Synchrotron Radiation Research OrganizationThe University of TokyoTokyoJapan
- Present address:
Center for Research on Green Sustainable ChemistryTottori UniversityTottoriJapan
| | - Hiroshi Masumoto
- Biomedical Research Support CenterNagasaki University School of MedicineNagasakiJapan
| | - Jinglei Cheng
- Department of Anatomy and Molecular Cell BiologyNagoya University Graduate School of MedicineNagoyaJapan
| | - Toyoshi Fujimoto
- Research Institute for Diseases of Old AgeJuntendo University Graduate School of MedicineTokyoJapan
| | - Shuya Fukai
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
- Synchrotron Radiation Research OrganizationThe University of TokyoTokyoJapan
| | - Hisanori Horiuchi
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
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10
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Cuddy LK, Wani WY, Morella ML, Pitcairn C, Tsutsumi K, Fredriksen K, Justman CJ, Grammatopoulos TN, Belur NR, Zunke F, Subramanian A, Affaneh A, Lansbury PT, Mazzulli JR. Stress-Induced Cellular Clearance Is Mediated by the SNARE Protein ykt6 and Disrupted by α-Synuclein. Neuron 2019; 104:869-884.e11. [PMID: 31648898 PMCID: PMC6895429 DOI: 10.1016/j.neuron.2019.09.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 06/05/2019] [Accepted: 08/30/2019] [Indexed: 12/23/2022]
Abstract
Age-related neurodegenerative disorders are characterized by a slow, persistent accumulation of aggregated proteins. Although cells can elicit physiological responses to enhance cellular clearance and counteract accumulation, it is unclear how pathogenic proteins evade this process in disease. We find that Parkinson's disease α-synuclein perturbs the physiological response to lysosomal stress by impeding the SNARE protein ykt6. Cytosolic ykt6 is normally autoinhibited by a unique farnesyl-mediated regulatory mechanism; however, during lysosomal stress, it activates and redistributes into membranes to preferentially promote hydrolase trafficking and enhance cellular clearance. α-Synuclein aberrantly binds and deactivates ykt6 in patient-derived neurons, thereby disabling the lysosomal stress response and facilitating protein accumulation. Activating ykt6 by small-molecule farnesyltransferase inhibitors restores lysosomal activity and reduces α-synuclein in patient-derived neurons and mice. Our findings indicate that α-synuclein creates a permissive environment for aggregate persistence by inhibiting regulated cellular clearance and provide a therapeutic strategy to restore protein homeostasis by harnessing SNARE activity.
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Affiliation(s)
- Leah K Cuddy
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Willayat Y Wani
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Martino L Morella
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Caleb Pitcairn
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Kotaro Tsutsumi
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Kristina Fredriksen
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | | | | | - Nandkishore R Belur
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Friederike Zunke
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Institute of Biochemistry, Christian-Albrechts-Universität zu Kiel, 24118 Kiel, Germany
| | - Aarthi Subramanian
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Amira Affaneh
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Peter T Lansbury
- Lysosomal Therapeutics, Inc., Cambridge, MA 02139, USA; Department of Neurology, Harvard Medical School, Cambridge, MA 02139, USA
| | - Joseph R Mazzulli
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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11
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Kriegenburg F, Bas L, Gao J, Ungermann C, Kraft C. The multi-functional SNARE protein Ykt6 in autophagosomal fusion processes. Cell Cycle 2019; 18:639-651. [PMID: 30836834 PMCID: PMC6464585 DOI: 10.1080/15384101.2019.1580488] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/06/2019] [Accepted: 01/29/2019] [Indexed: 01/01/2023] Open
Abstract
Autophagy is a degradative pathway in which cytosolic material is enwrapped within double membrane vesicles, so-called autophagosomes, and delivered to lytic organelles. SNARE (Soluble N-ethylmaleimide sensitive factor attachment protein receptor) proteins are key to drive membrane fusion of the autophagosome and the lytic organelles, called lysosomes in higher eukaryotes or vacuoles in plants and yeast. Therefore, the identification of functional SNARE complexes is central for understanding fusion processes and their regulation. The SNARE proteins Syntaxin 17, SNAP29 and Vamp7/VAMP8 are responsible for the fusion of autophagosomes with lysosomes in higher eukaryotes. Recent studies reported that the R-SNARE Ykt6 is an additional SNARE protein involved in autophagosome-lytic organelle fusion in yeast, Drosophila, and mammals. These current findings point to an evolutionarily conserved role of Ykt6 in autophagosome-related fusion events. Here, we briefly summarize the principal mechanisms of autophagosome-lytic organelle fusion, with a special focus on Ykt6 to highlight some intrinsic features of this unusual SNARE protein.
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Affiliation(s)
- Franziska Kriegenburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Levent Bas
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Jieqiong Gao
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Christian Ungermann
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg
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12
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Abstract
Formation of the autolysosome involves SNARE-mediated autophagosome-lysosome fusion, which is mediated by a combination of the Qa SNARE STX17 (syntaxin 17), the Qbc SNARE SNAP29 and the R-SNAREs VAMP7/8. 2 very recent reports have now implicated another R-SNARE with a longin domain, YKT6, in this fusion process. Interestingly, these reports painted two different pictures of YKT6's involvement. Studies in HeLa cells indicated that YKT6, acting independently of STX17, could form a separate SNARE complex with SNAP29 and another Qa SNARE to mediate autophagosome-lysosome fusion. Conversely, work in Drosophila larvae fat cells showed that while Ykt6 could form a SNARE complex with Snap29 and Syx17/Stx17, it is readily outcompeted by lysosomal Vamp7 in this regard. Moreover, its activity in autophagosome-lysosome fusion is not impaired by mutation of the supposedly critical ionic zero-layer residue from R to Q. In this regard, YKT6 may therefore act in a noncanonical way to regulate fusion. Here, we ponder on the fresh mechanistic perspectives on the final membrane fusion step of macroautophagy/autophagy offered by these new findings. Further, we propose another possible mechanism as to how YKT6 might act, which may provide some reconciliation to the differences observed. Abbreviations: LD: longin domain.
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Affiliation(s)
- Cheryl Qian Ying Yong
- a Department of Biochemistry, Yong Loo Lin School of Medicine , National University of Singapore , Singapore
| | - Bor Luen Tang
- a Department of Biochemistry, Yong Loo Lin School of Medicine , National University of Singapore , Singapore.,b NUS Graduate School for Integrative Sciences and Engineering , National University of Singapore , Singapore
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13
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Wu S, Wang D, Weng J, Liu J, Wang W. A revisit of the conformational dynamics of SNARE protein rYkt6. Biochem Biophys Res Commun 2018; 503:2841-2847. [PMID: 30119892 DOI: 10.1016/j.bbrc.2018.08.052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 08/06/2018] [Indexed: 12/12/2022]
Abstract
N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins are involved in the fusion of vesicles with their target membranes. R-SNARE protein Ykt6 is one of the most conserved SNARE in eukaryotes. The conformational state of Ykt6 is regulated by the lipidations at its C-terminal motif. Previous studies show that the binding of dodecylphosphocholine (DPC) can stabilize a closed conformation of rat Ykt6 (rYkt6) and mimic the farnesylated rYkt6. Despite this model, the detailed conformational dynamics of Ykt6 is still unclear. Here, we combined smFRET and MD simulation to demonstrate that the un-lipidated rYkt6 adopts five major conformational states. DPC binding shifts the conformational distribution toward the more closed states. At the same time, there remain considerable fractions of open and semi-open conformations in the presence of DPC. These newly revealed dynamic features of rYkt6 are consistent with its unique functional diversity in neuronal cells.
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Affiliation(s)
- Shaowen Wu
- Multiscale Research Institute of Complex Systems, Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai, PR China
| | - Dongdong Wang
- Multiscale Research Institute of Complex Systems, Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai, PR China
| | - Jingwei Weng
- Multiscale Research Institute of Complex Systems, Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai, PR China
| | - Jianwei Liu
- Multiscale Research Institute of Complex Systems, Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai, PR China.
| | - Wenning Wang
- Multiscale Research Institute of Complex Systems, Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai, PR China.
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14
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Abstract
Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins constitute the core membrane fusion machinery of intracellular transport and intercellular communication. A little more than ten years ago, it was proposed that the long N-terminal domain of a subset of SNAREs, henceforth called the longin domain, could be a crucial regulator with multiple functions in membrane trafficking. Structural, biochemical and cell biology studies have now produced a large set of data that support this hypothesis and indicate a role for the longin domain in regulating the sorting and activity of SNAREs. Here, we review the first decade of structure-function data on the three prototypical longin SNAREs: Ykt6, VAMP7 and Sec22b. We will, in particular, highlight the conserved molecular mechanisms that allow longin domains to fold back onto the fusion-inducing SNARE coiled-coil domain, thereby inhibiting membrane fusion, and describe the interactions of longin SNAREs with proteins that regulate their intracellular sorting. This dual function of the longin domain in regulating both the membrane localization and membrane fusion activity of SNAREs points to its role as a key regulatory module of intracellular trafficking.
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Affiliation(s)
- Frédéric Daste
- Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, CNRS UMR 7592, Membrane Traffic in Health & Disease, INSERM ERL U950, Paris F-75013, France
| | - Thierry Galli
- Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, CNRS UMR 7592, Membrane Traffic in Health & Disease, INSERM ERL U950, Paris F-75013, France
| | - David Tareste
- Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, CNRS UMR 7592, Membrane Traffic in Health & Disease, INSERM ERL U950, Paris F-75013, France
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15
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Jang H, Abraham SJ, Chavan TS, Hitchinson B, Khavrutskii L, Tarasova NI, Nussinov R, Gaponenko V. Mechanisms of membrane binding of small GTPase K-Ras4B farnesylated hypervariable region. J Biol Chem 2015; 290:9465-77. [PMID: 25713064 PMCID: PMC4392252 DOI: 10.1074/jbc.m114.620724] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 02/19/2015] [Indexed: 01/08/2023] Open
Abstract
K-Ras4B belongs to a family of small GTPases that regulates cell growth, differentiation and survival. K-ras is frequently mutated in cancer. K-Ras4B association with the plasma membrane through its farnesylated and positively charged C-terminal hypervariable region (HVR) is critical to its oncogenic function. However, the structural mechanisms of membrane association are not fully understood. Here, using confocal microscopy, surface plasmon resonance, and molecular dynamics simulations, we observed that K-Ras4B can be distributed in rigid and loosely packed membrane domains. Its membrane binding domain interaction with phospholipids is driven by membrane fluidity. The farnesyl group spontaneously inserts into the disordered lipid microdomains, whereas the rigid microdomains restrict the farnesyl group penetration. We speculate that the resulting farnesyl protrusion toward the cell interior allows oligomerization of the K-Ras4B membrane binding domain in rigid microdomains. Unlike other Ras isoforms, K-Ras4B HVR contains a single farnesyl modification and positively charged polylysine sequence. The high positive charge not only modulates specific HVR binding to anionic phospholipids but farnesyl membrane orientation. Phosphorylation of Ser-181 prohibits spontaneous farnesyl membrane insertion. The mechanism illuminates the roles of HVR modifications in K-Ras4B targeting microdomains of the plasma membrane and suggests an additional function for HVR in regulation of Ras signaling.
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Affiliation(s)
- Hyunbum Jang
- From the Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research and Cancer and Inflammation Program, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Sherwin J Abraham
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, Departments of Biochemistry and Molecular Genetics and
| | - Tanmay S Chavan
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, Medicinal Chemistry, University of Illinois, Chicago, Illinois 60607, and
| | | | - Lyuba Khavrutskii
- From the Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research and Cancer and Inflammation Program, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Nadya I Tarasova
- Cancer and Inflammation Program, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702,
| | - Ruth Nussinov
- From the Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research and Cancer and Inflammation Program, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702, Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vadim Gaponenko
- Departments of Biochemistry and Molecular Genetics and Medicinal Chemistry, University of Illinois, Chicago, Illinois 60607, and
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16
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Ward BP, Ottaway NL, Perez-Tilve D, Ma D, Gelfanov VM, Tschöp MH, Dimarchi RD. Peptide lipidation stabilizes structure to enhance biological function. Mol Metab 2013; 2:468-79. [PMID: 24327962 DOI: 10.1016/j.molmet.2013.08.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 08/23/2013] [Accepted: 08/25/2013] [Indexed: 10/26/2022] Open
Abstract
Medicines that decrease body weight and restore nutrient tolerance could improve human diabetes and obesity treatment outcomes. We developed lipid-acylated glucagon analogs that are co-agonists for the glucagon and glucagon-like peptide 1 receptors, and stimulate weight loss and plasma glucose lowering in pre-diabetic obese mice. Our studies identified lipid acylation (lipidation) can increase and balance in vitro potencies of select glucagon analogs for the two aforementioned receptors in a lipidation site-dependent manner. A general capacity for lipidation to enhance the secondary structure of glucagon analogs was recognized, and the energetics of this effect quantified. The molecular structure of a lipid-acylated glucagon analog in water was also characterized. These results support that lipidation can modify biological activity through thermodynamically-favorable intramolecular interactions which stabilize structure. This establishes use of lipidation to achieve specific pharmacology and implicates similar endogenous post-translational modifications as physiological tools capable of refining biological action in means previously underappreciated.
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Affiliation(s)
- Brian P Ward
- Department of Chemistry, Indiana University, Bloomington, IN, USA
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17
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Avadisian M, Gunning PT. Extolling the benefits of molecular therapeutic lipidation. MOLECULAR BIOSYSTEMS 2013; 9:2179-88. [DOI: 10.1039/c3mb70147f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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18
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Johannessen L, Remsberg J, Gaponenko V, Adams KM, Barchi JJ, Tarasov SG, Jiang S, Tarasova NI. Peptide structure stabilization by membrane anchoring and its general applicability to the development of potent cell-permeable inhibitors. Chembiochem 2011; 12:914-21. [PMID: 21365731 DOI: 10.1002/cbic.201000563] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Indexed: 11/08/2022]
Abstract
Isolated protein motifs that are involved in interactions with their binding partners can be used to inhibit these interactions. However, peptides corresponding to protein fragments tend to have no defined secondary or tertiary structure in the absence of scaffolding by the rest of protein molecule. This results in low inhibitor potency. NMR and CD spectroscopy studies of lipopeptide inhibitors of the Hedgehog pathway revealed that membrane anchoring allows the cell membrane to function as a scaffold and facilitate the folding of short peptides. In addition, lipidation enhances cell permeability and increases the concentration of the compounds near the membrane, thus facilitating potent inhibition. The general applicability of this rational approach was further confirmed by the generation of selective antagonists of the insulin-like growth factor 1 receptor with GI(50) values in the nanomolar range. Lipopeptides corresponding to protein fragments were found to serve as potent and selective inhibitors of a number of nondruggable molecular targets.
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Affiliation(s)
- Liv Johannessen
- Cancer and Inflammation Program, Center for Cancer Research NCI-Frederick, Frederick, MD, 21702, USA
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19
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Combination of NMR spectroscopy and X-ray crystallography offers unique advantages for elucidation of the structural basis of protein complex assembly. SCIENCE CHINA-LIFE SCIENCES 2011; 54:101-11. [PMID: 21318479 DOI: 10.1007/s11427-011-4137-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 07/07/2010] [Indexed: 10/18/2022]
Abstract
NMR spectroscopy and X-ray crystallography are two premium methods for determining the atomic structures of macro-biomolecular complexes. Each method has unique strengths and weaknesses. While the two techniques are highly complementary, they have generally been used separately to address the structure and functions of biomolecular complexes. In this review, we emphasize that the combination of NMR spectroscopy and X-ray crystallography offers unique power for elucidating the structures of complicated protein assemblies. We demonstrate, using several recent examples from our own laboratory, that the exquisite sensitivity of NMR spectroscopy in detecting the conformational properties of individual atoms in proteins and their complexes, without any prior knowledge of conformation, is highly valuable for obtaining the high quality crystals necessary for structure determination by X-ray crystallography. Thus NMR spectroscopy, in addition to answering many unique structural biology questions that can be addressed specifically by that technique, can be exceedingly powerful in modern structural biology when combined with other techniques including X-ray crystallography and cryo-electron microscopy.
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20
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Ayong L, DaSilva T, Mauser J, Allen CM, Chakrabarti D. Evidence for prenylation-dependent targeting of a Ykt6 SNARE in Plasmodium falciparum. Mol Biochem Parasitol 2011; 175:162-8. [DOI: 10.1016/j.molbiopara.2010.11.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 11/01/2010] [Accepted: 11/05/2010] [Indexed: 10/18/2022]
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21
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Schönichen A, Bigalke JM, Urbanke C, Grzesiek S, Dames SA, Geyer M. A flexible bipartite coiled coil structure is required for the interaction of Hexim1 with the P-TEFB subunit cyclin T1. Biochemistry 2010; 49:3083-91. [PMID: 20210365 DOI: 10.1021/bi902072f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transcription elongation is regulated by the cellular protein Hexim1, which inhibits phosphorylation of RNA polymerase II by interacting with the positive transcription elongation factor P-TEFb. Hexim1 binds directly to Cyclin T1 of P-TEFb with its coiled coil domain that is subdivided into a highly polar N-terminal segment containing nonconservative residues in the dimer interface and a C-terminal segment with an evolutionarily conserved sequence composition. Here we show that the noncanonical sequence composition of the first coiled coil segment is required for the interaction with Cyclin T1 while the second segment keeps the Cyclin T-binding domain dimeric upon binding. Both coiled coil segments exhibit distinct melting points as shown by heat denaturation experiments using circular dichroism spectroscopy. Deletion of the central stammer motif (Delta316-318) leads to a single denaturation reaction, suggesting formation of a continuous coiled coil. Mutation of noncanonical coiled coil residues K284 and Y291 to valines in the dimer interface of the first segment only slightly increases its stability. Concomitantly, deletion of the stammer but not the double point mutation led to a reduced affinity for Cyclin T1 as shown by isothermal titration calorimetry. Moreover, Cyclin T1 bound Hexim1 with a 1:2 stoichiometry, whereas truncation of the C-terminal coiled coil led to formation of an equimolar complex. These observations suggest that binding to Cyclin T1 induces an asymmetry or sterical hindrance in the first coiled coil segment of dimeric Hexim1 that disallows formation of a 2:2 complex as further supported by analytical ultracentrifugation and cross-linking experiments.
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Affiliation(s)
- André Schönichen
- Max-Planck-Institut für molekulare Physiologie, Abteilung Physikalische Biochemie, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
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22
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Vivona S, Liu CW, Strop P, Rossi V, Filippini F, Brunger AT. The longin SNARE VAMP7/TI-VAMP adopts a closed conformation. J Biol Chem 2010; 285:17965-73. [PMID: 20378544 PMCID: PMC2878558 DOI: 10.1074/jbc.m110.120972] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
SNARE protein complexes are key mediators of exocytosis by juxtaposing opposing membranes, leading to membrane fusion. SNAREs generally consist of one or two core domains that can form a four-helix bundle with other SNARE core domains. Some SNAREs, such as syntaxin target-SNAREs and longin vesicular-SNAREs, have independent, folded N-terminal domains that can interact with their respective SNARE core domains and thereby affect the kinetics of SNARE complex formation. This autoinhibition mechanism is believed to regulate the role of the longin VAMP7/TI-VAMP in neuronal morphogenesis. Here we use nuclear magnetic resonance spectroscopy to study the longin-SNARE core domain interaction for VAMP7. Using complete backbone resonance assignments, chemical shift perturbations analysis, and hydrogen/deuterium exchange experiments, we conclusively show that VAMP7 adopts a preferentially closed conformation in solution. Taken together, the closed conformation of longins is conserved, in contrast to the syntaxin family of SNAREs for which mixtures of open and closed states have been observed. This may indicate different regulatory mechanisms for SNARE complexes containing syntaxins and longins, respectively.
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Affiliation(s)
- Sandro Vivona
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, USA
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23
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Wen W, Yu J, Pan L, Wei Z, Weng J, Wang W, Ong YS, Tran THT, Hong W, Zhang M. Lipid-Induced conformational switch controls fusion activity of longin domain SNARE Ykt6. Mol Cell 2010; 37:383-95. [PMID: 20159557 DOI: 10.1016/j.molcel.2010.01.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 05/01/2009] [Accepted: 12/29/2009] [Indexed: 11/26/2022]
Abstract
While most SNAREs are permanently anchored to membranes by their transmembrane domains, the dually lipidated SNARE Ykt6 is found both on intracellular membranes and in the cytosol. The cytosolic Ykt6 is inactive due to the autoinhibition of the SNARE core by its longin domain, although the molecular basis of this inhibition is unknown. Here, we demonstrate that unlipidated Ykt6 adopts multiple conformations, with a small population in the closed state. The structure of Ykt6 in complex with a fatty acid suggests that, upon farnesylation, the Ykt6 SNARE core forms four alpha helices that wrap around the longin domain, forming a dominantly closed conformation. The fatty acid, buried in a hydrophobic groove formed between the longin domain and its SNARE core, is essential for maintaining the autoinhibited conformation of Ykt6. Our study reveals that the posttranslationally attached farnesyl group can actively regulate Ykt6 fusion activity in addition to its anticipated membrane-anchoring role.
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Affiliation(s)
- Wenyu Wen
- Institutes of Biomedical Sciences, Fudan University, Shanghai, P.R. China
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24
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Fres JM, Müller S, Praefcke GJK. Purification of the CaaX-modified, dynamin-related large GTPase hGBP1 by coexpression with farnesyltransferase. J Lipid Res 2010; 51:2454-9. [PMID: 20348589 PMCID: PMC2903825 DOI: 10.1194/jlr.d005397] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Over a hundred proteins in eukaryotic cells carry a C-terminal CaaX box sequence, which targets them for posttranslational isoprenylation of the cysteine residue. This modification, catalyzed by either farnesyl or geranylgeranyl transferase, converts them into peripheral membrane proteins. Isoprenylation is usually followed by proteolytic cleavage of the aaX tripeptide and methylation of the carboxyl group of the newly exposed isoprenylcysteine. The C-terminal modification regulates the cellular localization and biological activity of isoprenylated proteins. We have established a strategy to produce and purify recombinant farnesylated guanylate-binding protein 1 (hGBP1), a dynamin-related large GTPase. Our system is based on the coexpression of hGBP1 with the two subunits of human farnesyltransferase in Escherichia coli and a chromatographic separation of farnesylated and unmodified protein. Farnesylated hGBP1 displays altered GTPase activity and is able to interact with liposomes in the activated state.
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Affiliation(s)
- Julia M Fres
- Center for Molecular Medicine Cologne, Institute for Genetics, Zülpicher Strasse 47, 50674 Köln, Germany
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25
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Rich RL, Myszka DG. Grading the commercial optical biosensor literature-Class of 2008: 'The Mighty Binders'. J Mol Recognit 2010; 23:1-64. [PMID: 20017116 DOI: 10.1002/jmr.1004] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Optical biosensor technology continues to be the method of choice for label-free, real-time interaction analysis. But when it comes to improving the quality of the biosensor literature, education should be fundamental. Of the 1413 articles published in 2008, less than 30% would pass the requirements for high-school chemistry. To teach by example, we spotlight 10 papers that illustrate how to implement the technology properly. Then we grade every paper published in 2008 on a scale from A to F and outline what features make a biosensor article fabulous, middling or abysmal. To help improve the quality of published data, we focus on a few experimental, analysis and presentation mistakes that are alarmingly common. With the literature as a guide, we want to ensure that no user is left behind.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT 84132, USA
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Baumgart F, Corral-Escariz M, Pérez-Gil J, Rodríguez-Crespo I. Palmitoylation of R-Ras by human DHHC19, a palmitoyl transferase with a CaaX box. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:592-604. [PMID: 20074548 DOI: 10.1016/j.bbamem.2010.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 12/17/2009] [Accepted: 01/04/2010] [Indexed: 11/24/2022]
Abstract
Mammalian proteins that contain an aspartate-histidine-histidine-cysteine-(DHHC) motif have been recently identified as a group of membrane-associated palmitoyl acyltransferases (PATs). Among the several protein substrates known to become palmitoylated by DHHC PATs are small GTPases prenylated at their carboxy-terminal end, such as H-Ras or N-Ras, eNOS, kinases myristoylated at their N-terminal end, such as Lck, and many transmembrane proteins and channels. We have focused our studies on the product of the human gene DHHC19, a putative palmitoyl transferase that, interestingly, displays a conserved CaaX box at its carboxy-terminal end. We show herein that the amino acid sequence present at the carboxy-terminus of DHHC19 is able to exclude a green fluorescent protein (GFP) reporter from the nucleus and direct it towards perinuclear regions. Transfection of full-length DHHC19 in COS7 cells reveals a perinuclear distribution, in analogy to other palmitoyl transferases, with a strong colocalization with the trans-Golgi markers Gal-T and TGN38. We have tested several small GTPases that are known to be palmitoylated as possible substrates of DHHC19. Although DHHC19 failed to increase the palmitoylation of H-Ras, N-Ras, K-Ras4A, RhoB or Rap2 it increased the palmitoylation of R-Ras approximately two-fold. The increased palmitoylation of R-Ras cotransfected with DHHC19 is accompanied by an augmented association with membranes as well as with rafts/caveolae. Finally, using both wild-type and an activated GTP bound form of R-Ras (G38V), we also show that the increased palmitoylation of R-Ras due to DHHC19 coexpression is accompanied by an enhanced viability of the transfected cells.
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Affiliation(s)
- Florian Baumgart
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid 28040, Spain
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27
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Gurden MDJ, Holland AJ, van Zon W, Tighe A, Vergnolle MA, Andres DA, Spielmann HP, Malumbres M, Wolthuis RMF, Cleveland DW, Taylor SS. Cdc20 is required for the post-anaphase, KEN-dependent degradation of centromere protein F. J Cell Sci 2010; 123:321-30. [PMID: 20053638 DOI: 10.1242/jcs.062075] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Progression through mitosis and cytokinesis requires the sequential proteolysis of several cell-cycle regulators. This proteolysis is mediated by the ubiquitin-proteasome system, with the E3 ligase being the anaphase-promoting complex, also known as the cyclosome (APC/C). The APC/C is regulated by two activators, namely Cdc20 and Cdh1. The current view is that prior to anaphase, the APC/C is activated by Cdc20, but that following anaphase, APC/C switches to Cdh1-dependent activation. However, here we present an analysis of the kinetochore protein Cenp-F that is inconsistent with this notion. Although it has long been appreciated that Cenp-F is degraded sometime during or after mitosis, exactly when and how has not been clear. Here we show that degradation of Cenp-F initiates about six minutes after anaphase, and that this is dependent on a C-terminal KEN-box. Although these two observations are consistent with Cenp-F being a substrate of Cdh1-activated APC/C, Cenp-F is degraded normally in Cdh1-null cells. By contrast, RNAi-mediated repression of APC/C subunits or Cdc20 does inhibit Cenp-F degradation. These findings therefore suggest that the APC/C does not simply 'switch' upon anaphase onset; rather, our observations indicate that Cdc20 also contributes to post-anaphase activation of the APC/C. We also show that the post-anaphase, KEN-box-dependent degradation of Cenp-F requires it to be farnesylated, a post-translational modification usually linked to membrane association. Because so many of the behaviours of Cenp-F are farnesylation-dependent, we suggest that this modification plays a more global role in Cenp-F function.
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Affiliation(s)
- Mark D J Gurden
- Faculty of Life Sciences, Michael Smith Building, University of Manchester, Manchester M13 9PT, UK
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28
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Czudnochowski N, Vollmuth F, Baumann S, Vogel-Bachmayr K, Geyer M. Specificity of Hexim1 and Hexim2 complex formation with cyclin T1/T2, importin alpha and 7SK snRNA. J Mol Biol 2009; 395:28-41. [PMID: 19883659 DOI: 10.1016/j.jmb.2009.10.055] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 10/26/2009] [Accepted: 10/27/2009] [Indexed: 10/20/2022]
Abstract
Positive transcription elongation factor b (P-TEFb) stimulates the transition from transcription initiation to productive elongation by phosphorylation of the C-terminal domain of RNA polymerase II. P-TEFb consists of the cyclin-dependent kinase Cdk9 and a T-type cyclin and is regulated by the small nuclear RNA 7SK and the coupling protein Hexim1 or Hexim2. In this study, we analyzed the tripartite protein-RNA complex formation between Hexim, Cyclin T and 7SK snRNA. Using isothermal titration calorimetry, we observed higher affinities for Cyclin T1-Hexim1 and Cyclin T2-Hexim2 complex formations compared with the interactions in reverse. Importin alpha, which is part of the Ran-mediated nuclear import pathway, bound Hexim1 and Hexim2 with dissociation constants of 2.0 and 0.5 muM, respectively. Furthermore, tripartite complex formations between Cyclin T, Hexim and Importin alpha showed the suitability of a collaborative nuclear import pathway for Cyclin T. Electrophoretic mobility shift assays using radioactively labelled full-length 7SK snRNA revealed a tight association of the RNA to Cyclin T1-Hexim1 with dissociation constants lower than 0.3 muM. Similar binding affinities were recorded for both Hexim orthologues to a 66-mer double-stranded 5' hairpin loop encompassing nucleotides 23-88 of 7SK, while a 39-mer fragment, resulting from different RNA folding predictions, did not bind as tightly. These results provide the molecular basis for the generation of a core complex for the inhibition of P-TEFb.
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Affiliation(s)
- Nadine Czudnochowski
- Abteilung Physikalische Biochemie, Max-Planck-Institut für molekulare Physiologie, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany
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29
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Poschner BC, Langosch D. Stabilization of conformationally dynamic helices by covalently attached acyl chains. Protein Sci 2009; 18:1801-5. [PMID: 19569191 DOI: 10.1002/pro.155] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Acylation of proteins is known to mediate membrane attachment and to influence subcellular sorting. Here, we report that acylation can stabilize secondary structure. Circular dichroism spectroscopy showed that N-terminal attachment of acyl chains decreases the ability of an intrinsically flexible hydrophobic model peptide to refold from an alpha-helical state to beta-sheet in response to changing solvent conditions. Acylation also stabilized the membrane-embedded alpha-helix. This increase of global helix stability did not result from decreased local conformational dynamics of the helix backbone as assessed by deuterium/hydrogen-exchange experiments. We concluded that acylation can stabilize the structure of intrinsically dynamic helices and may thus prevent misfolding.
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Affiliation(s)
- Bernhard C Poschner
- Lehrstuhl Chemie der Biopolymere, Technische Universität München, 85354 Freising, Germany
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30
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Kang TS, Kini RM. Structural determinants of protein folding. Cell Mol Life Sci 2009; 66:2341-61. [PMID: 19367367 PMCID: PMC11115868 DOI: 10.1007/s00018-009-0023-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 03/07/2009] [Accepted: 03/20/2009] [Indexed: 12/11/2022]
Abstract
The last several decades have seen an explosion of knowledge in the field of structural biology. With critical advances in spectroscopic techniques in examining structures of biomacromolecules, in maturation of molecular biology techniques, as well as vast improvements in computation prowess, protein structures are now being elucidated at an unprecedented rate. In spite of all the recent advances, the protein folding puzzle remains as one of the fundamental biochemical challenges. A facet to this empiric problem is the structural determinants of protein folding. What are the driving forces that pivot a polypeptide chain to a specific conformation amongst the vast conformation space? In this review, we shall discuss some of the structural determinants to protein folding that have been identified in the recent decades.
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Affiliation(s)
- Tse Siang Kang
- The Scripps Research Institute, 10550 North Torrey Pines Road GAC 1200, La Jolla, CA 92037 USA
- Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Block S4, Singapore, 117543 Singapore
| | - R. Manjunatha Kini
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Block S3 #03-17, Singapore, 117543 Singapore
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31
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Summers DW, Douglas PM, Ren HY, Cyr DM. The type I Hsp40 Ydj1 utilizes a farnesyl moiety and zinc finger-like region to suppress prion toxicity. J Biol Chem 2008; 284:3628-39. [PMID: 19056735 DOI: 10.1074/jbc.m807369200] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Type I Hsp40s are molecular chaperones that protect neurons from degeneration by modulating the aggregation state of amyloid-forming proteins. How Type I Hsp40s recognize beta-rich, amyloid-like substrates is currently unknown. Thus, we examined the mechanism for binding between the Type I Hsp40 Ydj1 and the yeast prion [RNQ+]. Ydj1 recognized the Gln/Asn-rich prion domain from Rnq1 specifically when it assembled into the amyloid-like [RNQ+] prion state. Upon deletion of YDJ1, overexpression of the Rnq1 prion domain killed yeast. Surprisingly, binding and suppression of prion domain toxicity by Ydj1 was dependent upon farnesylation of its C-terminal CAAX box and action of a zinc finger-like region. In contrast, folding of luciferase was independent of farnesylation, yet required the zinc finger-like region of Ydj1 and a conserved hydrophobic peptide-binding pocket. Type I Hsp40s contain at least three different domains that work in concert to bind different protein conformers. The combined action of a farnesyl moiety and zinc finger-like region enable Type I Hsp40s to recognize amyloid-like substrates and prevent formation of cytotoxic protein species.
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Affiliation(s)
- Daniel W Summers
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina 27599-7090, USA
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32
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Meiringer CTA, Auffarth K, Hou H, Ungermann C. Depalmitoylation of Ykt6 prevents its entry into the multivesicular body pathway. Traffic 2008; 9:1510-21. [PMID: 18541004 DOI: 10.1111/j.1600-0854.2008.00778.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The dually lipidated SNARE Ykt6 is found on intracellular membranes and in the cytosol. In this study, we show that Ykt6 localizes to the Golgi as well as endosomal and vacuolar membranes in vivo. The ability of Ykt6 to cycle between the cytosol and the membranes depends on the intramolecular interaction of the N-terminal longin and C-terminal SNARE domains and not on either domain alone. A mutant deficient in this interaction accumulates on membranes and--in contrast to the wild-type protein--does not get released from vacuoles. Our data also indicate that Ykt6 is a substrate of the DHHC (Asp-His-His-Cys) acyltransferase network. Overexpression of the vacuolar acyltransferase Pfa3 drives the F42S mutant not only to the vacuole but also into the vacuolar lumen. Thus, depalmitoylation and release of Ykt6 are needed for its recycling and to circumvent its entry into the endosomal multivesicular body pathway.
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