1
|
Morán‐Lalangui M, Coutinho A, Prieto M, Fedorov A, Pérez‐Gil J, Loura LMS, García‐Álvarez B. Exploring protein-protein interactions and oligomerization state of pulmonary surfactant protein C (SP-C) through FRET and fluorescence self-quenching. Protein Sci 2024; 33:e4835. [PMID: 37984447 PMCID: PMC10731621 DOI: 10.1002/pro.4835] [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: 07/10/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/22/2023]
Abstract
Pulmonary surfactant (PS) is a lipid-protein complex that forms films reducing surface tension at the alveolar air-liquid interface. Surfactant protein C (SP-C) plays a key role in rearranging the lipids at the PS surface layers during breathing. The N-terminal segment of SP-C, a lipopeptide of 35 amino acids, contains two palmitoylated cysteines, which affect the stability and structure of the molecule. The C-terminal region comprises a transmembrane α-helix that contains a ALLMG motif, supposedly analogous to a well-studied dimerization motif in glycophorin A. Previous studies have demonstrated the potential interaction between SP-C molecules using approaches such as Bimolecular Complementation assays or computational simulations. In this work, the oligomerization state of SP-C in membrane systems has been studied using fluorescence spectroscopy techniques. We have performed self-quenching and FRET assays to analyze dimerization of native palmitoylated SP-C and a non-palmitoylated recombinant version of SP-C (rSP-C) using fluorescently labeled versions of either protein reconstituted in different lipid systems mimicking pulmonary surfactant environments. Our results reveal that doubly palmitoylated native SP-C remains primarily monomeric. In contrast, non-palmitoylated recombinant SP-C exhibits dimerization, potentiated at high concentrations, especially in membranes with lipid phase separation. Therefore, palmitoylation could play a crucial role in stabilizing the monomeric α-helical conformation of SP-C. Depalmitoylation, high protein densities as a consequence of membrane compartmentalization, and other factors may all lead to the formation of protein dimers and higher-order oligomers, which could have functional implications under certain pathological conditions and contribute to membrane transformations associated with surfactant metabolism and alveolar homeostasis.
Collapse
Affiliation(s)
- Mishelle Morán‐Lalangui
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
| | - Ana Coutinho
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
- Department of Chemistry and BiochemistryFaculty of Sciences, University of LisbonLisbonPortugal
| | - Manuel Prieto
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
| | - Alexander Fedorov
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
| | - Jesús Pérez‐Gil
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
| | - Luís M. S. Loura
- Department of Chemistry, Coimbra Chemistry Centre, Institute of Molecular Sciences (CQC‐IMS)University of CoimbraCoimbraPortugal
- CNC Centre for Neuroscience and Cell Biology, University of CoimbraCoimbraPortugal
- Faculty of PharmacyUniversity of CoimbraCoimbraPortugal
| | - Begoña García‐Álvarez
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
- Department of Biochemistry and Molecular BiologyFaculty of Chemistry, Complutense UniversityMadridSpain
| |
Collapse
|
2
|
Chakraborty A, Blatch GL, Edkins AL. Bimolecular Fluorescence Complementation Assay to Evaluate HSP90-Client Protein Interactions in Cells. Methods Mol Biol 2023; 2693:95-103. [PMID: 37540429 DOI: 10.1007/978-1-0716-3342-7_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Protein-protein interactions (PPI) in cells play a pivotal role in cellular function and dynamics. Cellular proteostasis is maintained by PPI networks between molecular chaperones, co-chaperones, and client proteins. Consequently, strategies to visualize and analyze PPI in cells are useful in understanding protein homeostasis regulation. The Bimolecular Fluorescence Complementation (BiFC) assay has emerged as a useful tool for studying PPI between proteins in live or fixed cells. BiFC is based on the detection of fluorescence generated when interacting protein pairs, produced as fusion proteins with either the N- or C-terminal fragment of a fluorescent protein, are in sufficient proximity to permit reconstitution of the split fluorophore. Here, we describe the application of the BiFC assay to a model of chaperone-client interactions using Hsp90 and the validated client protein CDK4. This assay allows for the distribution and spatiotemporal analysis of HSP90-CDK4 complexes in live or fixed cells and is amenable to studying the effects of inhibitors and mutations on chaperone-client protein networks.
Collapse
Affiliation(s)
- Abir Chakraborty
- Biomedical Biotechnology Research Unit (BioBRU), Department of Biochemistry and Microbiology, Rhodes University, Makhanda, South Africa
| | - Gregory L Blatch
- Biomedical Biotechnology Research Unit (BioBRU), Department of Biochemistry and Microbiology, Rhodes University, Makhanda, South Africa
- Biomedical Research and Drug Discovery Research Group, Faculty of Health Sciences, Higher Colleges of Technology, Sharjah, United Arab Emirates
- The Vice Chancellery, The University of Notre Dame Australia, Fremantle, WA, Australia
| | - Adrienne L Edkins
- Biomedical Biotechnology Research Unit (BioBRU), Department of Biochemistry and Microbiology, Rhodes University, Makhanda, South Africa.
| |
Collapse
|
3
|
Kalis AK, Sterrett MC, Armstrong C, Ballmer A, Burkstrand K, Chilson E, Emlen E, Ferrer E, Loeb S, Olin T, Tran K, Wheeler A, Ross Wolff J. Hox proteins interact to pattern neuronal subtypes in Caenorhabditis elegans males. Genetics 2022; 220:iyac010. [PMID: 35137058 PMCID: PMC8982040 DOI: 10.1093/genetics/iyac010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 01/10/2022] [Indexed: 11/14/2022] Open
Abstract
Hox transcription factors are conserved regulators of neuronal subtype specification on the anteroposterior axis in animals, with disruption of Hox gene expression leading to homeotic transformations of neuronal identities. We have taken advantage of an unusual mutation in the Caenorhabditis elegans Hox gene lin-39, lin-39(ccc16), which transforms neuronal fates in the C. elegans male ventral nerve cord in a manner that depends on a second Hox gene, mab-5. We have performed a genetic analysis centered around this homeotic allele of lin-39 in conjunction with reporters for neuronal target genes and protein interaction assays to explore how LIN-39 and MAB-5 exert both flexibility and specificity in target regulation. We identify cis-regulatory modules in neuronal reporters that are both region-specific and Hox-responsive. Using these reporters of neuronal subtype, we also find that the lin-39(ccc16) mutation disrupts neuronal fates specifically in the region where lin-39 and mab-5 are coexpressed, and that the protein encoded by lin-39(ccc16) is active only in the absence of mab-5. Moreover, the fates of neurons typical to the region of lin-39-mab-5 coexpression depend on both Hox genes. Our genetic analysis, along with evidence from Bimolecular Fluorescence Complementation protein interaction assays, supports a model in which LIN-39 and MAB-5 act at an array of cis-regulatory modules to cooperatively activate and to individually activate or repress neuronal gene expression, resulting in regionally specific neuronal fates.
Collapse
Affiliation(s)
- Andrea K Kalis
- Department of Biology, St. Catherine University, St. Paul, MN 55105, USA
| | - Maria C Sterrett
- Department of Biology, Carleton College, Northfield, MN 55057, USA
| | - Cecily Armstrong
- Department of Biology, St. Catherine University, St. Paul, MN 55105, USA
| | | | - Kylie Burkstrand
- Department of Biology, St. Catherine University, St. Paul, MN 55105, USA
| | - Elizabeth Chilson
- Department of Biology, St. Catherine University, St. Paul, MN 55105, USA
| | - Estee Emlen
- Department of Biology, Carleton College, Northfield, MN 55057, USA
| | - Emma Ferrer
- Department of Biology, Carleton College, Northfield, MN 55057, USA
| | - Seanna Loeb
- Department of Biology, St. Catherine University, St. Paul, MN 55105, USA
| | - Taylor Olin
- Department of Biology, St. Catherine University, St. Paul, MN 55105, USA
| | - Kevin Tran
- Department of Biology, Carleton College, Northfield, MN 55057, USA
| | - Andrew Wheeler
- Department of Biology, Carleton College, Northfield, MN 55057, USA
| | | |
Collapse
|
4
|
Groß VE, Gershkovich MM, Schöneberg T, Kaiser A, Prömel S. NanoBRET in C. elegans illuminates functional receptor interactions in real time. BMC Mol Cell Biol 2022; 23:8. [PMID: 35100990 PMCID: PMC8805316 DOI: 10.1186/s12860-022-00405-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/11/2022] [Indexed: 11/10/2022] Open
Abstract
Background Protein-protein interactions form the basis of every organism and thus, investigating their dynamics, intracellular protein localization, trafficking and interactions of distinct proteins such as receptors and their ligand-binding are of general interest. Bioluminescence resonance energy transfer (BRET) is a powerful tool to investigate these aspects in vitro. Since in vitro approaches mostly neglect the more complex in vivo situation, we established BRET as an in vivo tool for studying protein interactions in the nematode C. elegans. Results We generated worms expressing NanoBRET sensors and elucidated the interaction of two ligand-G protein-coupled receptor (GPCR) pairs, the neuropeptide receptor NPR-11 and the Adhesion GPCR LAT-1. Furthermore, we adapted the enhanced bystander BRET technology to measure subcellular protein localization. Using this approach, we traced ligand-induced internalization of NPR-11 in vivo. Conclusions Our results indicate that in vivo NanoBRET is a tool to investigate specific protein interactions and localization in a physiological setting in real time in the living organism C. elegans. Supplementary Information The online version contains supplementary material available at 10.1186/s12860-022-00405-w.
Collapse
Affiliation(s)
- Victoria Elisabeth Groß
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103, Leipzig, Germany.,Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | | | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103, Leipzig, Germany
| | - Anette Kaiser
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, 04103, Leipzig, Germany.
| | - Simone Prömel
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103, Leipzig, Germany. .,Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
| |
Collapse
|
5
|
Li S, Xiong Q, Chen M, Wang B, Yang X, Yang M, Wang Q, Cui Z, Ge F. Long noncoding RNA HOTAIR interacts with Y-Box Protein-1 (YBX1) to regulate cell proliferation. Life Sci Alliance 2021; 4:4/9/e202101139. [PMID: 34266873 PMCID: PMC8321693 DOI: 10.26508/lsa.202101139] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 02/06/2023] Open
Abstract
The authors determined that HOTAIR specifically bind to YBX1 and promote its nuclear translocation, and then regulating cell proliferation by stimulating the PI3K/Akt and ERK/RSK signaling pathways. HOTAIR is a long noncoding RNA (lncRNA) which serves as an important factor regulating diverse processes linked with cancer development. Here, we used comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS) to explore the HOTAIR-protein interactome. We were able to identify 348 proteins interacting with HOTAIR, allowing us to establish a heavily interconnected HOTAIR-protein interaction network. We further developed a novel near-infrared fluorescent protein (iRFP)-trimolecular fluorescence complementation (TriFC) system to assess the interaction between HOTAIR and its interacting proteins. Then, we determined that HOTAIR specifically binds to YBX1, promotes YBX1 nuclear translocation, and stimulates the PI3K/Akt and ERK/RSK signaling pathways. We further demonstrated that HOTAIR exerts its effects on cell proliferation, at least in part, through the regulation of two YBX1 downstream targets phosphoenolpyruvate carboxykinase 2 (PCK2) and platelet derived growth factor receptor β. Our findings revealed a novel mechanism, whereby an lncRNA is able to regulate cell proliferation via altering intracellular protein localization. Moreover, the imaging tools developed herein have excellent potential for future in vivo imaging of lncRNA–protein interaction.
Collapse
Affiliation(s)
- Siting Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qian Xiong
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Minghai Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Bing Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xue Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Mingkun Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Zongqiang Cui
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China .,University of Chinese Academy of Sciences, Beijing, China
| | - Feng Ge
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China .,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
6
|
Leveraging a gain-of-function allele of Caenorhabditis elegans paqr-1 to elucidate membrane homeostasis by PAQR proteins. PLoS Genet 2020; 16:e1008975. [PMID: 32750056 PMCID: PMC7428288 DOI: 10.1371/journal.pgen.1008975] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 08/14/2020] [Accepted: 07/01/2020] [Indexed: 12/12/2022] Open
Abstract
The C. elegans proteins PAQR-2 (a homolog of the human seven-transmembrane domain AdipoR1 and AdipoR2 proteins) and IGLR-2 (a homolog of the mammalian LRIG proteins characterized by a single transmembrane domain and the presence of immunoglobulin domains and leucine-rich repeats in their extracellular portion) form a complex that protects against plasma membrane rigidification by promoting the expression of fatty acid desaturases and the incorporation of polyunsaturated fatty acids into phospholipids, hence increasing membrane fluidity. In the present study, we leveraged a novel gain-of-function allele of PAQR-1, a PAQR-2 paralog, to carry out structure-function studies. We found that the transmembrane domains of PAQR-2 are responsible for its functional requirement for IGLR-2, that PAQR-1 does not require IGLR-2 but acts via the same pathway as PAQR-2, and that the divergent N-terminal cytoplasmic domains of the PAQR-1 and PAQR-2 proteins serve a regulatory function and may regulate access to the catalytic site of these proteins. We also show that overexpression of human AdipoR1 or AdipoR2 alone is sufficient to confer increased palmitic acid resistance in HEK293 cells, and thus act in a manner analogous to the PAQR-1 gain-of-function allele.
Collapse
|
7
|
Day NJ, Wang X, Voronina E. In Situ Detection of Ribonucleoprotein Complex Assembly in the C. elegans Germline using Proximity Ligation Assay. J Vis Exp 2020. [PMID: 32449701 DOI: 10.3791/60982] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Understanding when and where protein-protein interactions (PPIs) occur is critical to understanding protein function in the cell and how broader processes such as development are affected. The Caenorhabditis elegans germline is a great model system for studying PPIs that are related to the regulation of stem cells, meiosis, and development. There are a variety of well-developed techniques that allow proteins of interest to be tagged for recognition by standard antibodies, making this system advantageous for proximity ligation assay (PLA) reactions. As a result, the PLA is able to show where PPIs occur in a spatial and temporal manner in germlines more effectively than alternative approaches. Described here is a protocol for the application and quantification of this technology to probe PPIs in the C. elegans germline.
Collapse
Affiliation(s)
| | - Xiaobo Wang
- Division of Biological Sciences, University of Montana
| | | |
Collapse
|
8
|
Steinmetz EL, Dewald DN, Walldorf U. Homeodomain-interacting protein kinase phosphorylates the Drosophila Paired box protein 6 (Pax6) homologues Twin of eyeless and Eyeless. INSECT MOLECULAR BIOLOGY 2018; 27:198-211. [PMID: 29205612 DOI: 10.1111/imb.12363] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Homeodomain-interacting protein kinase (Hipk), the Drosophila homologue of mammalian HIPK2, plays several important roles in regulating differentiation, proliferation, apoptosis, and stress responses and acts as a mediator for signals of diverse pathways, such as Notch or Wingless signalling. The Paired box protein 6 (Pax6) has two Drosophila homologues, Twin of eyeless (Toy) and Eyeless (Ey). Both stand atop the retinal determination gene network (RDGN), which is essential for proper eye development in Drosophila. Here, we set Hipk and the master regulators Toy and Ey in an enzyme-substrate relationship. Furthermore, we prove a physical interaction between Toy and Hipk in vivo using bimolecular fluorescence complementation. Using in vitro kinase assays with different truncated Toy constructs and mutational analyses, we mapped four Hipk phosphorylation sites of Toy, one in the paired domain (Ser121 ) and three in the C-terminal transactivation domain of Toy (Thr395 , Ser410 and Thr452 ). The interaction and phosphorylation of the master regulator Toy by Hipk may be important for precise tuning of signalling within the RDGN and therefore for Drosophila eye development.
Collapse
Affiliation(s)
- E L Steinmetz
- Developmental Biology, Saarland University, Homburg, Germany
| | - D N Dewald
- Developmental Biology, Saarland University, Homburg, Germany
| | - U Walldorf
- Developmental Biology, Saarland University, Homburg, Germany
| |
Collapse
|
9
|
Regulation of WNT Signaling at the Neuromuscular Junction by the Immunoglobulin Superfamily Protein RIG-3 in Caenorhabditis elegans. Genetics 2017; 206:1521-1534. [PMID: 28515212 PMCID: PMC5500148 DOI: 10.1534/genetics.116.195297] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 05/11/2017] [Indexed: 12/17/2022] Open
Abstract
Perturbations in synaptic function could affect the normal behavior of an animal, making it important to understand the regulatory mechanisms of synaptic signaling. Previous work has shown that in Caenorhabditis elegans an immunoglobulin superfamily protein, RIG-3, functions in presynaptic neurons to maintain normal acetylcholine receptor levels at the neuromuscular junction (NMJ). In this study, we elucidate the molecular and functional mechanism of RIG-3. We demonstrate by genetic and BiFC (Bi-molecular Fluorescence Complementation) assays that presynaptic RIG-3 functions by directly interacting with the immunoglobulin domain of the nonconventional Wnt receptor, ROR receptor tyrosine kinase (RTK), CAM-1, which functions in postsynaptic body-wall muscles. This interaction in turn inhibits Wnt/LIN-44 signaling through the ROR/CAM-1 receptor, and allows for maintenance of normal acetylcholine receptor, AChR/ACR-16, levels at the neuromuscular synapse. Further, this work reveals that RIG-3 and ROR/CAM-1 function through the β-catenin/HMP-2 at the NMJ. Taken together, our results demonstrate that RIG-3 functions as an inhibitory molecule of the Wnt/LIN-44 signaling pathway through the RTK, CAM-1.
Collapse
|
10
|
Jeong DE, Lee D, Hwang SY, Lee Y, Lee JE, Seo M, Hwang W, Seo K, Hwang AB, Artan M, Son HG, Jo JH, Baek H, Oh YM, Ryu Y, Kim HJ, Ha CM, Yoo JY, Lee SJV. Mitochondrial chaperone HSP-60 regulates anti-bacterial immunity via p38 MAP kinase signaling. EMBO J 2017; 36:1046-1065. [PMID: 28283579 DOI: 10.15252/embj.201694781] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 02/08/2017] [Accepted: 02/10/2017] [Indexed: 12/13/2022] Open
Abstract
Mitochondria play key roles in cellular immunity. How mitochondria contribute to organismal immunity remains poorly understood. Here, we show that HSP-60/HSPD1, a major mitochondrial chaperone, boosts anti-bacterial immunity through the up-regulation of p38 MAP kinase signaling. We first identify 16 evolutionarily conserved mitochondrial components that affect the immunity of Caenorhabditis elegans against pathogenic Pseudomonas aeruginosa (PA14). Among them, the mitochondrial chaperone HSP-60 is necessary and sufficient to increase resistance to PA14. We show that HSP-60 in the intestine and neurons is crucial for the resistance to PA14. We then find that p38 MAP kinase signaling, an evolutionarily conserved anti-bacterial immune pathway, is down-regulated by genetic inhibition of hsp-60, and up-regulated by increased expression of hsp-60 Overexpression of HSPD1, the mammalian ortholog of hsp-60, increases p38 MAP kinase activity in human cells, suggesting an evolutionarily conserved mechanism. Further, cytosol-localized HSP-60 physically binds and stabilizes SEK-1/MAP kinase kinase 3, which in turn up-regulates p38 MAP kinase and increases immunity. Our study suggests that mitochondrial chaperones protect host eukaryotes from pathogenic bacteria by up-regulating cytosolic p38 MAPK signaling.
Collapse
Affiliation(s)
- Dae-Eun Jeong
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Dongyeop Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Sun-Young Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Yujin Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Jee-Eun Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Mihwa Seo
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Wooseon Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Keunhee Seo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Ara B Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Murat Artan
- Information Technology Convergence Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Heehwa G Son
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Jay-Hyun Jo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Haeshim Baek
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Young Min Oh
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Youngjae Ryu
- Research Division, Korea Brain Research Institute, Daegu, Korea
| | - Hyung-Jun Kim
- Research Division, Korea Brain Research Institute, Daegu, Korea
| | - Chang Man Ha
- Research Division, Korea Brain Research Institute, Daegu, Korea
| | - Joo-Yeon Yoo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Seung-Jae V Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea .,School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea.,Information Technology Convergence Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| |
Collapse
|
11
|
Svensk E, Devkota R, Ståhlman M, Ranji P, Rauthan M, Magnusson F, Hammarsten S, Johansson M, Borén J, Pilon M. Caenorhabditis elegans PAQR-2 and IGLR-2 Protect against Glucose Toxicity by Modulating Membrane Lipid Composition. PLoS Genet 2016; 12:e1005982. [PMID: 27082444 PMCID: PMC4833288 DOI: 10.1371/journal.pgen.1005982] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/16/2016] [Indexed: 12/19/2022] Open
Abstract
In spite of the worldwide impact of diabetes on human health, the mechanisms behind glucose toxicity remain elusive. Here we show that C. elegans mutants lacking paqr-2, the worm homolog of the adiponectin receptors AdipoR1/2, or its newly identified functional partner iglr-2, are glucose intolerant and die in the presence of as little as 20 mM glucose. Using FRAP (Fluorescence Recovery After Photobleaching) on living worms, we found that cultivation in the presence of glucose causes a decrease in membrane fluidity in paqr-2 and iglr-2 mutants and that genetic suppressors of this sensitivity act to restore membrane fluidity by promoting fatty acid desaturation. The essential roles of paqr-2 and iglr-2 in the presence of glucose are completely independent from daf-2 and daf-16, the C. elegans homologs of the insulin receptor and its downstream target FoxO, respectively. Using bimolecular fluorescence complementation, we also show that PAQR-2 and IGLR-2 interact on plasma membranes and thus may act together as a fluidity sensor that controls membrane lipid composition.
Collapse
Affiliation(s)
- Emma Svensk
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Parmida Ranji
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Manish Rauthan
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Magnusson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Sofia Hammarsten
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Maja Johansson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
12
|
Kodama Y, Hu CD. Bimolecular fluorescence complementation (BiFC): a 5-year update and future perspectives. Biotechniques 2013; 53:285-98. [PMID: 23148879 DOI: 10.2144/000113943] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 09/28/2012] [Indexed: 11/23/2022] Open
Abstract
Over the past decade, bimolecular fluorescence complementation (BiFC) has emerged as a key technique to visualize protein-protein interactions in a variety of model organisms. The BiFC assay is based on reconstitution of an intact fluorescent protein when two complementary non-fluorescent fragments are brought together by a pair of interacting proteins. While the originally reported BiFC method has enabled the study of many protein-protein interactions, increasing demands to visualize protein-protein interactions under various physiological conditions have not only prompted a series of recent BiFC technology improvements, but also stimulated interest in developing completely new approaches. Here we review current BiFC technology, focusing on the development and improvement of BiFC systems, the understanding of split sites in fluorescent proteins, and enhancements in the signal-to-noise ratio. In addition, we provide perspectives on possible future improvements of the technique.
Collapse
Affiliation(s)
- Yutaka Kodama
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi, Japan.
| | | |
Collapse
|
13
|
Diversity in genetic in vivo methods for protein-protein interaction studies: from the yeast two-hybrid system to the mammalian split-luciferase system. Microbiol Mol Biol Rev 2012; 76:331-82. [PMID: 22688816 DOI: 10.1128/mmbr.05021-11] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The yeast two-hybrid system pioneered the field of in vivo protein-protein interaction methods and undisputedly gave rise to a palette of ingenious techniques that are constantly pushing further the limits of the original method. Sensitivity and selectivity have improved because of various technical tricks and experimental designs. Here we present an exhaustive overview of the genetic approaches available to study in vivo binary protein interactions, based on two-hybrid and protein fragment complementation assays. These methods have been engineered and employed successfully in microorganisms such as Saccharomyces cerevisiae and Escherichia coli, but also in higher eukaryotes. From single binary pairwise interactions to whole-genome interactome mapping, the self-reassembly concept has been employed widely. Innovative studies report the use of proteins such as ubiquitin, dihydrofolate reductase, and adenylate cyclase as reconstituted reporters. Protein fragment complementation assays have extended the possibilities in protein-protein interaction studies, with technologies that enable spatial and temporal analyses of protein complexes. In addition, one-hybrid and three-hybrid systems have broadened the types of interactions that can be studied and the findings that can be obtained. Applications of these technologies are discussed, together with the advantages and limitations of the available assays.
Collapse
|
14
|
Kahner BN, Kato H, Banno A, Ginsberg MH, Shattil SJ, Ye F. Kindlins, integrin activation and the regulation of talin recruitment to αIIbβ3. PLoS One 2012; 7:e34056. [PMID: 22457811 PMCID: PMC3311585 DOI: 10.1371/journal.pone.0034056] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 02/21/2012] [Indexed: 11/18/2022] Open
Abstract
Talins and kindlins bind to the integrin β3 cytoplasmic tail and both are required for effective activation of integrin αIIbβ3 and resulting high-affinity ligand binding in platelets. However, binding of the talin head domain alone to β3 is sufficient to activate purified integrin αIIbβ3 in vitro. Since talin is localized to the cytoplasm of unstimulated platelets, its re-localization to the plasma membrane and to the integrin is required for activation. Here we explored the mechanism whereby kindlins function as integrin co-activators. To test whether kindlins regulate talin recruitment to plasma membranes and to αIIbβ3, full-length talin and kindlin recruitment to β3 was studied using a reconstructed CHO cell model system that recapitulates agonist-induced αIIbβ3 activation. Over-expression of kindlin-2, the endogenous kindlin isoform in CHO cells, promoted PAR1-mediated and talin-dependent ligand binding. In contrast, shRNA knockdown of kindlin-2 inhibited ligand binding. However, depletion of kindlin-2 by shRNA did not affect talin recruitment to the plasma membrane, as assessed by sub-cellular fractionation, and neither over-expression of kindlins nor depletion of kindlin-2 affected talin interaction with αIIbβ3 in living cells, as monitored by bimolecular fluorescence complementation. Furthermore, talin failed to promote kindlin-2 association with αIIbβ3 in CHO cells. In addition, purified talin and kindlin-3, the kindlin isoform expressed in platelets, failed to promote each other's binding to the β3 cytoplasmic tail in vitro. Thus, kindlins do not promote initial talin recruitment to αIIbβ3, suggesting that they co-activate integrin through a mechanism independent of recruitment.
Collapse
Affiliation(s)
- Bryan N Kahner
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | | | | | | | | | | |
Collapse
|
15
|
Tian G, Lu Q, Zhang L, Kohalmi SE, Cui Y. Detection of protein interactions in plant using a gateway compatible bimolecular fluorescence complementation (BiFC) system. J Vis Exp 2011:3473. [PMID: 21947026 PMCID: PMC3230203 DOI: 10.3791/3473] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
We have developed a BiFC technique to test the interaction between two proteins in vivo. This is accomplished by splitting a yellow fluorescent protein (YFP) into two non-overlapping fragments. Each fragment is cloned in-frame to a gene of interest. These constructs can then be co-transformed into Nicotiana benthamiana via Agrobacterium mediated transformation, allowing the transit expression of fusion proteins. The reconstitution of YFP signal only occurs when the inquest proteins interact (1-7). To test and validate the protein-protein interactions, BiFC can be used together with yeast two hybrid (Y2H) assay. This may detect indirect interactions which can be overlooked in the Y2H. Gateway technology is a universal platform that enables researchers to shuttle the gene of interest (GOI) into as many expression and functional analysis systems as possible(8,9). Both the orientation and reading frame can be maintained without using restriction enzymes or ligation to make expression-ready clones. As a result, one can eliminate all the re-sequencing steps to ensure consistent results throughout the experiments. We have created a series of Gateway compatible BiFC and Y2H vectors which provide researchers with easy-to-use tools to perform both BiFC and Y2H assays(10). Here, we demonstrate the ease of using our BiFC system to test protein-protein interactions in N. benthamiana plants.
Collapse
Affiliation(s)
- Gang Tian
- Department of Biology, University of Western Ontario, Canada
| | | | | | | | | |
Collapse
|
16
|
Talaty P, Emery A, Everly DN. Characterization of the latent membrane protein 1 signaling complex of Epstein-Barr virus in the membrane of mammalian cells with bimolecular fluorescence complementation. Virol J 2011; 8:414. [PMID: 21864338 PMCID: PMC3173395 DOI: 10.1186/1743-422x-8-414] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 08/24/2011] [Indexed: 01/07/2023] Open
Abstract
Background Bimolecular fluorescence complementation (BiFC) is a novel technique to examine protein-protein interaction through the assembly of fluorescent proteins. In the present study, BiFC was used to study the assembly of the Epstein-Barr virus latent membrane protein 1 (LMP1) signaling complex within the membrane of mammalian cells. LMP1 signaling requires oligomerization, localization to lipid rafts, and association of the cytoplasmic domain to adaptor proteins, such as the tumor necrosis factor receptor associated factors (TRAFs). Methods LMP1-TRAF and LMP1-LMP1 interactions were assayed by BiFC using fluorescence microscopy and flow cytometry. Function of LMP1 BiFC contructs were confirmed by transformation assays and nuclear factor- κB (NF-κB) reporter assays. Results BiFC was observed between LMP1 and TRAF2 or TRAF3 and mutation of the LMP1 signaling domains reduced complementation. Fluorescence was observed in previously described LMP1 signaling locations. Oligomerization of LMP1 with itself induced complementation and BiFC. LMP1-BiFC constructs were fully functional in rodent fibroblast transformation assays and activation of NF-κB reporter activity. The BiFC domain partially suppressed some LMP1 mutant phenotypes. Conclusions Together these data suggest that BiFC is a unique and novel platform to identify and characterize proteins recruited to the LMP1-signaling complex.
Collapse
Affiliation(s)
- Pooja Talaty
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, Illinois 60064, USA
| | | | | |
Collapse
|
17
|
Miller RR, Okkema PG. The Caenorhabditis elegans T-box factor MLS-1 requires Groucho co-repressor interaction for uterine muscle specification. PLoS Genet 2011; 7:e1002210. [PMID: 21852953 PMCID: PMC3154951 DOI: 10.1371/journal.pgen.1002210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 06/15/2011] [Indexed: 11/18/2022] Open
Abstract
T-box proteins are conserved transcription factors that play crucial roles in development of all metazoans; and, in humans, mutations affecting T-box genes are associated with a variety of congenital diseases and cancers. Despite the importance of this transcription factor family, very little is known regarding how T-box factors regulate gene expression. The Caenorhabditis elegans genome contains 21 T-box genes, and their characterized functions include cell fate specification in a variety of tissues. The C. elegans Tbx1 sub-family member MLS-1 functions during larval development to specify the fate of non-striated uterine muscles; and, in mls-1 mutants, uterine muscles are transformed to a vulval muscle fate. Here we demonstrate that MLS-1 function depends on binding to the Groucho-family co-repressor UNC-37. MLS-1 interacts with UNC-37 via a conserved eh1 motif, and the MLS-1 eh1 motif is necessary for MLS-1 to specify uterine muscle fate. Moreover, unc-37 loss-of-function produces uterine muscle to vulval muscle fate transformation similar to those observed in mls-1 mutants. Based on these results, we conclude that MLS-1 specifies uterine muscle fate by repressing target gene expression, and this function depends on interaction with UNC-37. Moreover, we suggest that MLS-1 shares a common mechanism for transcriptional repression with related T-box factors in other animal phyla.
Collapse
Affiliation(s)
- Raymond R Miller
- Department of Biological Sciences, Laboratory for Molecular Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | | |
Collapse
|
18
|
Newman RH, Fosbrink MD, Zhang J. Genetically encodable fluorescent biosensors for tracking signaling dynamics in living cells. Chem Rev 2011; 111:3614-66. [PMID: 21456512 PMCID: PMC3092831 DOI: 10.1021/cr100002u] [Citation(s) in RCA: 260] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Robert H. Newman
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Matthew D. Fosbrink
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Jin Zhang
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| |
Collapse
|
19
|
Zhou J, Lin J, Zhou C, Deng X, Xia B. An improved bimolecular fluorescence complementation tool based on superfolder green fluorescent protein. Acta Biochim Biophys Sin (Shanghai) 2011; 43:239-44. [PMID: 21273204 DOI: 10.1093/abbs/gmq128] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Bimolecular fluorescence complementation (BiFC) has been widely used in the analysis of protein-protein interactions (PPIs) in recent years. There are many notable advantages of BiFC such as convenience and direct visualization of PPI in cells. However, BiFC has one common limitation: the separated non-fluorescent fragments can be spontaneously self-assembled into an intact protein, which leads to false-positive results. In this study, a pair of complementary fragments (sfGFPN and sfGFPC) was constructed by splitting superfolder GFP (sfGFP) between the 214 and 215 amino acid residue, and sfGFPC was mutated by site-directed gene mutagenesis to decrease the signal of negative control. Our results showed that mutations in sfGFPC (sfGFPC(m12)) can effectively decrease the signal of negative control. Thus, we provide an improved BiFC tool for the analysis of PPI. Further, since the self-assembly problem is a common shortcoming for application of BiFC, our research provides a feasible strategy for other BiFC candidate proteins with the same problem.
Collapse
Affiliation(s)
- Jun Zhou
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Biomedical Engineering, Beihang University, Beijing, China
| | | | | | | | | |
Collapse
|
20
|
Hsu CC, Moncaleano J, Wagner O. Sub-cellular distribution of UNC-104(KIF1A) upon binding to adaptors as UNC-16(JIP3), DNC-1(DCTN1/Glued) and SYD-2(Liprin-α) in C. elegans neurons. Neuroscience 2011; 176:39-52. [DOI: 10.1016/j.neuroscience.2010.12.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 12/19/2010] [Accepted: 12/23/2010] [Indexed: 10/18/2022]
|
21
|
An improved bimolecular fluorescence complementation assay with a high signal-to-noise ratio. Biotechniques 2011; 49:793-805. [PMID: 21091444 DOI: 10.2144/000113519] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Protein-protein interactions (PPIs) play crucial roles in various biological processes. Among biochemical, genetic, and imaging approaches that have been used for the study of PPIs, visualization of PPIs in living cells is the key to understanding their cellular functions. The bimolecular fluorescence complementation (BiFC) assay represents one of these imaging tools for direct visualization of PPIs in living cells. The BiFC assay is based on the structural complementation of two nonfluorescent N- and C-terminal fragments of a fluorescent protein when they are fused to a pair of interacting proteins. Although over 10 different fluorescent proteins have been used for BiFC assays, the two nonfluorescent fragments from all of these fluorescent proteins can spontaneously self-assemble, which contributes to background fluorescence and decreases the signal-to-noise (S/N) ratio in the BiFC assay. Here we report the identification of a mutation, I152L, that can specifically reduce self-assembly and decrease background fluorescence in a Venus-based BiFC system. This mutation allows a 4-fold increase in the S/N ratio of the BiFC assay in living cells. This improved Venus-based BiFC system will facilitate PPI studies in various biological research fields.
Collapse
|
22
|
Lee YR, Park JH, Hahm SH, Kang LW, Chung JH, Nam KH, Hwang KY, Kwon IC, Han YS. Development of bimolecular fluorescence complementation using Dronpa for visualization of protein-protein interactions in cells. Mol Imaging Biol 2011; 12:468-78. [PMID: 20373040 DOI: 10.1007/s11307-010-0312-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE We developed a bimolecular fluorescence complementation (BiFC) strategy using Dronpa, a new fluorescent protein with reversible photoswitching activity and fast responsibility to light, to monitor protein-protein interactions in cells. PROCEDURES Dronpa was split at residue Glu164 in order to generate two Dronpa fragments [Dronpa N-terminal: DN (Met1-Glu164), Dronpa C-terminal: DC (Gly165-Lys224)]. DN or DC was separately fused with C terminus of hHus1 or N terminus of hRad1. Flexible linker [(GGGGS)×2] was introduced to enhance Dronpa complementation by hHus1-hRad1 interaction. Furthermore, we developed expression vectors to visualize the interaction between hMYH and hHus1. Gene fragments corresponding to the coding regions of hMYH and hHus1 were N-terminally or C-terminally fused with DN and DC coding region. RESULTS Complemented Dronpa fluorescence was only observed in HEK293 cells cotransfected with hHus1-LDN and DCL-hRad1 expression vectors, but not with hHus1-LDN or DCL-hRad1 expression vector alone. Western blot analysis of immunoprecipitated samples using anti-c-myc or anti-flag showed that DN-fused hHus1 interacted with DC-fused hRad1. Complemented Dronpa fluorescence was also observed in cells cotransfected with hMYH-LDN and DCL-hHus1 expression vectors or hMYH-LDN and hHus1-LDC expression vectors. Furthermore, complemented Dronpa, induced by the interaction between hMYH-LDN and DCL-hHus1, showed almost identical photoswitching activity as that of native Dronpa. CONCLUSION These results demonstrate that BiFC using Dronpa can be successfully used to investigate protein-protein interaction in live cells. Furthermore, the fact that complemented Dronpa has a reversible photoswitching activity suggests that it can be used as a tool for tracking protein-protein interaction.
Collapse
Affiliation(s)
- You Ri Lee
- Department of Advanced Technology Fusion, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul, 143-701, Republic of Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
The BK channel is a Ca²+- and voltage-gated potassium channel with many important physiological functions. To identify proteins important to its function in vivo, we screened for Caenorhabditis elegans mutants that suppressed a lethargic phenotype caused by expressing a gain-of-function (gf) isoform of the BK channel α-subunit SLO-1. BKIP-1 (for BK channel interacting protein), a small peptide with no significant homology to any previously characterized molecules, was thus identified. BKIP-1 and SLO-1 showed similar expression and subcellular localization patterns and appeared to interact physically through discrete domains. bkip-1 loss-of-function (lf) mutants phenocopied slo-1(lf) mutants in behavior and synaptic transmission and suppressed the lethargy, egg-laying defect, and deficient neurotransmitter release caused by SLO-1(gf). In heterologous expression systems, BKIP-1 decreased the activation rate and shifted the conductance-voltage relationship of SLO-1 in a Ca²+-dependent manner and increased SLO-1 surface expression. Thus, BKIP-1 is a novel auxiliary subunit critical to SLO-1 function in vivo.
Collapse
|
24
|
Pétrin D, Hébert TE. Imaging-based approaches to understanding g protein-coupled receptor signalling complexes. Methods Mol Biol 2011; 756:37-60. [PMID: 21870219 DOI: 10.1007/978-1-61779-160-4_2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In the last 10 years, imaging assays based on resonance energy transfer (RET) and protein fragment complementation have made it possible to study interactions between components of G protein-coupled receptor (GPCR) signalling complexes in living cells under physiological conditions. Here, we consider the history of such approaches, the current tools available and how they have changed our understanding of GPCR signalling. We also discuss some theoretical and methodological issues important when combining the different types of assay.
Collapse
Affiliation(s)
- Darlaine Pétrin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada
| | | |
Collapse
|
25
|
Guo SJ, Hu JG, Zhao BM, Shen L, Wang R, Zhou JS, Lü HZ. Olig1 and ID4 interactions in living cells visualized by bimolecular fluorescence complementation technique. Mol Biol Rep 2010; 38:4637-42. [PMID: 21132377 DOI: 10.1007/s11033-010-0597-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 11/20/2010] [Indexed: 10/18/2022]
Abstract
Olig1, a member of class B basic-helix-loop-helix (bHLH), plays key roles in early oligodendrocyte specification. Inhibitors of DNA binding (Id) is another sub-class of HLH proteins, act as dominant-negative regulators of bHLH proteins, which can form heterodimers with class A or B bHLH proteins, but lack the critical basic DNA binding domain. Id4 was recently found to interact with olig1 and inhibit oligodendrocyte differentiation. However, there still no direct evidence to reveal the spatial and temporal interaction of olig1 and ID4 in living cells. In this study, we performed bimolecular fluorescence complementation (BiFC) analysis to further characterize the distinct subcellular localization of olig1, ID4 and their dimer in living SW1116 cells. To examine the subcellular localization of olig1 and ID4 by themselves, the olig1-EGFP or ID4-DsRed2 fusion proteins were also expressed in SW1116 cells, respectively. As predicted, the olig1-EGFP fusion proteins were located in the nucleus, and ID4-DsRed2 fusion proteins were located in the cytoplasm. When olig1-EGFP and ID4-DsRed2 fusion proteins were co-expressed, the green and red signals were co-located in the cytoplasm. Using BiFC, the strong BiFC signals could be detected in pBiFC-olig1VN173 and pBiFC-ID4VC155 co-transfected cells and the fluorescence signal was located in the cytoplasm. These results collectively confirmed that olig1 and ID4 could interact and form dimer in living cells, and ID4 could block the transport of olig1 from cytoplasm to nucleus.
Collapse
Affiliation(s)
- Shu-Jun Guo
- Department of Immunology, and Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Anhui 233030, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
26
|
Gohl C, Banovic D, Grevelhörster A, Bogdan S. WAVE forms hetero- and homo-oligomeric complexes at integrin junctions in Drosophila visualized by bimolecular fluorescence complementation. J Biol Chem 2010; 285:40171-9. [PMID: 20937809 DOI: 10.1074/jbc.m110.139337] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Dynamic actin polymerization drives a variety of morphogenetic events during metazoan development. Members of the WASP/WAVE protein family are central nucleation-promoting factors. They are embedded within regulatory networks of macromolecular complexes controlling Arp2/3-mediated actin nucleation in time and space. WAVE (Wiskott-Aldrich syndrome protein family verprolin-homologous protein) proteins are found in a conserved pentameric heterocomplex that contains Abi, Kette/Nap1, Sra-1/CYFIP, and HSPC300. Formation of the WAVE complex contributes to the localization, activity, and stability of the various WAVE proteins. Here, we established the Bimolecular Fluorescence Complementation (BiFC) technique in Drosophila to determine the subcellular localization of the WAVE complex in living flies. Using different split-YFP combinations, we are able to visualize the formation of the WAVE-Abi complex in vivo. We found that WAVE also forms dimers that are capable of forming higher order clusters with endogenous WAVE complex components. The N-terminal WAVE homology domain (WHD) of the WAVE protein mediates both WAVE-Abi and WAVE-WAVE interactions. Detailed localization analyses show that formation of WAVE complexes specifically takes place at basal cell compartments promoting actin polymerization. In the wing epithelium, hetero- and homooligomeric WAVE complexes co-localize with Integrin and Talin suggesting a role in integrin-mediated cell adhesion. RNAi mediated suppression of single components of the WAVE and the Arp2/3 complex in the wing further suggests that WAVE-dependent Arp2/3-mediated actin nucleation is important for the maintenance of stable integrin junctions.
Collapse
Affiliation(s)
- Christina Gohl
- Institut für Neurobiologie, Universität Münster, Badestr 9, 48149 Münster, Germany
| | | | | | | |
Collapse
|
27
|
α-Catulin CTN-1 is required for BK channel subcellular localization in C. elegans body-wall muscle cells. EMBO J 2010; 29:3184-95. [PMID: 20700105 DOI: 10.1038/emboj.2010.194] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 07/20/2010] [Indexed: 11/09/2022] Open
Abstract
The BK channel, a voltage- and Ca(2+)-gated large-conductance potassium channel with many important functions, is often localized at specific subcellular domains. Although proper subcellular localization is likely a prerequisite for the channel to perform its physiological functions, little is known about the molecular basis of localization. Here, we show that CTN-1, a homologue of mammalian α-catulin, is required for subcellular localization of SLO-1, the Caenorhabditis elegans BK channel α-subunit, in body-wall muscle cells. CTN-1 was identified in a genetic screen for mutants that suppressed a lethargic phenotype caused by expressing a gain-of-function (gf) isoform of SLO-1. In body-wall muscle cells, CTN-1 coclusters with SLO-1 at regions of dense bodies, which are Z-disk analogs of mammalian skeletal muscle. In ctn-1 loss-of-function (lf) mutants, SLO-1 was mislocalized in body-wall muscle but its transcription and protein level were unchanged. Targeted rescue of ctn-1(lf) in muscle was sufficient to reinstate the lethargic phenotype in slo-1(gf);ctn-1(lf). These results suggest that CTN-1 plays an important role in BK channel function by mediating channel subcellular localization.
Collapse
|
28
|
He B, Yu X, Margolis M, Liu X, Leng X, Etzion Y, Zheng F, Lu N, Quiocho FA, Danino D, Zhou Z. Live-cell imaging in Caenorhabditis elegans reveals the distinct roles of dynamin self-assembly and guanosine triphosphate hydrolysis in the removal of apoptotic cells. Mol Biol Cell 2010; 21:610-29. [PMID: 20016007 PMCID: PMC2820425 DOI: 10.1091/mbc.e09-05-0440] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Dynamins are large GTPases that oligomerize along membranes. Dynamin's membrane fission activity is believed to underlie many of its physiological functions in membrane trafficking. Previously, we reported that DYN-1 (Caenorhabditis elegans dynamin) drove the engulfment and degradation of apoptotic cells through promoting the recruitment and fusion of intracellular vesicles to phagocytic cups and phagosomes, an activity distinct from dynamin's well-known membrane fission activity. Here, we have detected the oligomerization of DYN-1 in living C. elegans embryos and identified DYN-1 mutations that abolish DYN-1's oligomerization or GTPase activities. Specifically, abolishing self-assembly destroys DYN-1's association with the surfaces of extending pseudopods and maturing phagosomes, whereas inactivating guanosine triphosphate (GTP) binding blocks the dissociation of DYN-1 from these membranes. Abolishing the self-assembly or GTPase activities of DYN-1 leads to common as well as differential phagosomal maturation defects. Whereas both types of mutations cause delays in the transient enrichment of the RAB-5 GTPase to phagosomal surfaces, only the self-assembly mutation but not GTP binding mutation causes failure in recruiting the RAB-7 GTPase to phagosomal surfaces. We propose that during cell corpse removal, dynamin's self-assembly and GTP hydrolysis activities establish a precise dynamic control of DYN-1's transient association to its target membranes and that this control mechanism underlies the dynamic recruitment of downstream effectors to target membranes.
Collapse
Affiliation(s)
- Bin He
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Poe JA, Smithgall TE. HIV-1 Nef dimerization is required for Nef-mediated receptor downregulation and viral replication. J Mol Biol 2009; 394:329-42. [PMID: 19781555 DOI: 10.1016/j.jmb.2009.09.047] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 09/15/2009] [Accepted: 09/17/2009] [Indexed: 10/20/2022]
Abstract
Nef, a human immunodeficiency virus type 1 (HIV-1) accessory factor capable of interaction with a diverse array of host cell signaling molecules, is essential for high-titer HIV replication and AIDS progression. Previous biochemical and structural studies have suggested that Nef may form homodimers and higher-order oligomers in HIV-infected cells, which may be required for both immune and viral receptor downregulation as well as viral replication. Using bimolecular fluorescence complementation, we provide the first direct evidence for Nef dimers within HIV host cells and identify the structural requirements for dimerization in vivo. Bimolecular fluorescence complementation analysis shows that the multiple hydrophobic and electrostatic interactions found within the dimerization interface of the Nef X-ray crystal structure are essential for dimerization in cells. Nef dimers localized to the plasma membrane as well as the trans-Golgi network, two subcellular localizations essential for Nef function. Mutations in the Nef dimerization interface dramatically reduced both Nef-induced CD4 downregulation and HIV replication. Viruses expressing dimerization-defective Nef mutants were disabled to the same extent as HIV that fails to express Nef in terms of replication. These results identify the Nef dimerization region as a potential molecular target for antiretroviral drug discovery.
Collapse
Affiliation(s)
- Jerrod A Poe
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, E1240 Biomedical Science Tower, Pittsburgh, PA 15261, USA
| | | |
Collapse
|
30
|
Hiatt SM, Duren HM, Shyu YJ, Ellis RE, Hisamoto N, Matsumoto K, Kariya KI, Kerppola TK, Hu CD. Caenorhabditis elegans FOS-1 and JUN-1 regulate plc-1 expression in the spermatheca to control ovulation. Mol Biol Cell 2009; 20:3888-95. [PMID: 19570917 DOI: 10.1091/mbc.e08-08-0833] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Fos and Jun are components of activator protein-1 (AP-1) and play crucial roles in the regulation of many cellular, developmental, and physiological processes. Caenorhabditis elegans fos-1 has been shown to act in uterine and vulval development. Here, we provide evidence that C. elegans fos-1 and jun-1 control ovulation, a tightly regulated rhythmic program in animals. Knockdown of fos-1 or jun-1 blocks dilation of the distal spermathecal valve, a critical step for the entry of mature oocytes into the spermatheca for fertilization. Furthermore, fos-1 and jun-1 regulate the spermathecal-specific expression of plc-1, a gene that encodes a phospholipase C (PLC) isozyme that is rate-limiting for inositol triphosphate production and ovulation, and overexpression of PLC-1 rescues the ovulation defect in fos-1(RNAi) worms. Unlike fos-1, regulation of ovulation by jun-1 requires genetic interactions with eri-1 and lin-15B, which are involved in the RNA interference pathway and chromatin remodeling, respectively. At least two isoforms of jun-1 are coexpressed with fos-1b in the spermatheca, and different AP-1 dimers formed between these isoforms have distinct effects on the activation of a reporter gene. These findings uncover a novel role for FOS-1 and JUN-1 in the reproductive system and establish C. elegans as a model for studying AP-1 dimerization.
Collapse
Affiliation(s)
- Susan M Hiatt
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, IN 47907, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Hopper-Borge EA, Nasto RE, Ratushny V, Weiner LM, Golemis EA, Astsaturov I. Mechanisms of tumor resistance to EGFR-targeted therapies. Expert Opin Ther Targets 2009; 13:339-62. [PMID: 19236156 PMCID: PMC2670612 DOI: 10.1517/14712590902735795] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Much effort has been devoted to development of cancer therapies targeting EGFR, based on its role in regulating cell growth. Small-molecule and antibody EGFR inhibitors have clinical roles based on their efficacy in a subset of cancers, generally as components of combination therapies. Many cancers are either initially resistant to EGFR inhibitors or become resistant during treatment, limiting the efficacy of these reagents. OBJECTIVE/METHODS To review cellular resistance mechanisms to EGFR-targeted therapies. RESULTS/CONCLUSIONS The best validated of these mechanisms include activation of classic ATP-binding casette (ABC) multidrug transporters; activation or mutation of EGFR; and overexpression or activation of signaling proteins operating in relation to EGFR. We discuss current efforts and potential strategies to override these sources of resistance. We describe emerging systems-biology-based concepts of alternative resistance to EGFR-targeted therapies, and discuss their implications for use of EGFR-targeted and other targeted therapies.
Collapse
Affiliation(s)
- Elizabeth A Hopper-Borge
- Fox Chase Cancer Center, W462, 333 Cottman Ave., Philadelphia, PA 19111, USA, Tel: (215) 728-2500; Fax: -3616; E-mail:
| | - Rochelle E Nasto
- Fox Chase Cancer Center, W462, 333 Cottman Ave., Philadelphia, PA 19111, USA, Tel: (215) 728-2500; Fax: -3616; E-mail:
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Vladimir Ratushny
- Fox Chase Cancer Center, W462, 333 Cottman Ave., Philadelphia, PA 19111, USA, Tel: (215) 728-2500; Fax: -3616; E-mail:
- Department of Biochemistry, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - Louis M Weiner
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057-1468, USA
| | - Erica A Golemis
- Fox Chase Cancer Center, W462, 333 Cottman Ave., Philadelphia, PA 19111, USA, Tel: (215) 728-2500; Fax: -3616; E-mail:
| | - Igor Astsaturov
- Fox Chase Cancer Center, W462, 333 Cottman Ave., Philadelphia, PA 19111, USA, Tel: (215) 728-2500; Fax: -3616; E-mail:
| |
Collapse
|
32
|
Dittman J. Chapter 2 Worm Watching: Imaging Nervous System Structure and Function in Caenorhabditis elegans. ADVANCES IN GENETICS 2009; 65:39-78. [DOI: 10.1016/s0065-2660(09)65002-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
|
33
|
Kerppola TK. Overcoming uncertainty through advances in fluorescence imaging of molecular processes in cells. Methods 2008; 45:183-4. [PMID: 18675216 PMCID: PMC2556219 DOI: 10.1016/j.ymeth.2008.07.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2008] [Accepted: 07/20/2008] [Indexed: 01/16/2023] Open
Affiliation(s)
- Tom K Kerppola
- Department of Biological Chemistry, Howard Hughes Medical Institute, University of Michigan School of Medicine, Ann Arbor 48109-0650, USA.
| |
Collapse
|
34
|
Shyu YJ, Hu CD. Fluorescence complementation: an emerging tool for biological research. Trends Biotechnol 2008; 26:622-30. [PMID: 18804297 DOI: 10.1016/j.tibtech.2008.07.006] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 07/20/2008] [Accepted: 07/22/2008] [Indexed: 11/29/2022]
Abstract
Numerous technologies based on utilizing fluorescent proteins have been developed for biological research, and fluorescence complementation (FC) is a recent application for visualization of molecular events in living cells and organisms. Currently, ten fluorescent proteins have been demonstrated to support FC. Over the past five years, FC-based technologies have been developed to visualize a variety of molecular events, such as protein-protein interactions, post-translational modifications, protein folding, conformational changes, RNA-protein interactions, mRNA localization and DNA hybridization. In addition, FC has also been used for drug discovery. These applications are providing fascinating insights into many biological processes. Here, we review the principles and applications of FC technologies, discuss their current challenges and examine prospects for future advances.
Collapse
Affiliation(s)
- Y John Shyu
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Cancer Center, Purdue University, West Lafayette, IN 47907, USA
| | | |
Collapse
|