1
|
Khan ES, Sankaran S, Paez JI, Muth C, Han MKL, Del Campo A. Retraction: Photoactivatable Hsp47: A Tool to Regulate Collagen Secretion and Assembly. Adv Sci (Weinh) 2023; 10:e2304457. [PMID: 37582689 PMCID: PMC10427363 DOI: 10.1002/advs.202304457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Adv. Sci. 2019, 6, 1801982 DOI: 10.1002/advs.201801982 The above article, published online on May 3, 2019, in Wiley Online Library (https://doi.org/10.1002/advs.201801982), has been retracted by agreement between the authors, the journal Editor-in-Chief Kirsten Severing, and Wiley-VCH GmbH. The retraction has been agreed on following concerns raised by a third party and a subsequent investigation by the corresponding authors. Data depicted in Figure 4 and Figure 5 could not be reproduced in follow-up experiments. Therefore, the conclusions associated with those figures in the article are considered invalid. E.S.K. participated in the study design, performed measurements, analyzed the data, compiled the figures and participated in manuscript writing. A.d.C. and S.S. participated in the study design, research supervision, and manuscript writing. J.I.P. participated in the study design. M.K.L.H. participated in research supervision and manuscript revision. C.M. assisted with the experimental procedures and data collection.
Collapse
|
2
|
Alhayek A, Khan ES, Schönauer E, Däinghaus T, Shafiei R, Voos K, Han MKL, Ducho C, Posselt G, Wessler S, Brandstetter H, Haupenthal J, del Campo A, Hirsch AKH. Inhibition of Collagenase Q1 of
Bacillus cereus
as a Novel Antivirulence Strategy for the Treatment of Skin‐Wound Infections. Advanced Therapeutics 2022; 5:2100222. [PMID: 35310821 PMCID: PMC7612511 DOI: 10.1002/adtp.202100222] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Despite the progress in surgical techniques and antibiotic prophylaxis, opportunistic wound infections with Bacillus cereus remain a public health problem. Secreted toxins are one of the main factors contributing to B. cereus pathogenicity. A promising strategy to treat such infections is to target these toxins and not the bacteria. Although the exoenzymes produced by B. cereus are thoroughly investigated, little is known about the role of B. cereus collagenases in wound infections. In this report, the collagenolytic activity of secreted collagenases (Col) is characterized in the B. cereus culture supernatant (csn) and its isolated recombinantly produced ColQ1 is characterized. The data reveals that ColQ1 causes damage on dermal collagen (COL). This results in gaps in the tissue, which might facilitate the spread of bacteria. The importance of B. cereus collagenases is also demonstrated in disease promotion using two inhibitors. Compound 2 shows high efficacy in peptidolytic, gelatinolytic, and COL degradation assays. It also preserves the fibrillar COLs in skin tissue challenged with ColQ1, as well as the viability of skin cells treated with B. cereus csn. A Galleria mellonella model highlights the significance of collagenase inhibition in vivo.
Collapse
Affiliation(s)
- Alaa Alhayek
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) Helmholtz Centre for Infection Research (HZI) 38124 Saarbrücken Germany
- Department of Pharmacy Saarland University, Saarbrücken Campus Campus E8.1 66123 Saarbrücken Germany
| | - Essak S. Khan
- Leibniz Institute for New Materials (INM) Saarland University Campus D2 2 66123 Saarbrücken Germany
| | - Esther Schönauer
- Department of Biosciences and Medical Biology Hellbrunner Str. 34 University of Salzburg Salzburg 5020 Austria
| | - Tobias Däinghaus
- Leibniz Institute for New Materials (INM) Saarland University Campus D2 2 66123 Saarbrücken Germany
| | - Roya Shafiei
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) Helmholtz Centre for Infection Research (HZI) 38124 Saarbrücken Germany
| | - Katrin Voos
- Department of Pharmacy Pharmaceutical and Medicinal Chemistry Saarland University Campus C2 3 66123 Saarbrücken Germany
| | - Mitchell K. L. Han
- Leibniz Institute for New Materials (INM) Saarland University Campus D2 2 66123 Saarbrücken Germany
| | - Christian Ducho
- Department of Pharmacy Pharmaceutical and Medicinal Chemistry Saarland University Campus C2 3 66123 Saarbrücken Germany
| | - Gernot Posselt
- Department of Biosciences and Medical Biology Hellbrunner Str. 34 University of Salzburg Salzburg 5020 Austria
| | - Silja Wessler
- Department of Biosciences and Medical Biology Hellbrunner Str. 34 University of Salzburg Salzburg 5020 Austria
| | - Hans Brandstetter
- Department of Biosciences and Medical Biology Hellbrunner Str. 34 University of Salzburg Salzburg 5020 Austria
| | - Jörg Haupenthal
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) Helmholtz Centre for Infection Research (HZI) 38124 Saarbrücken Germany
| | - Aránzazu del Campo
- Leibniz Institute for New Materials (INM) Saarland University Campus D2 2 66123 Saarbrücken Germany
- Chemistry Department Saarland University 66123 Saarbrücken Germany
| | - Anna K. H. Hirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) Helmholtz Centre for Infection Research (HZI) 38124 Saarbrücken Germany
- Department of Pharmacy Saarland University, Saarbrücken Campus Campus E8.1 66123 Saarbrücken Germany
| |
Collapse
|
3
|
Zheng Y, Han MKL, Zhao R, Blass J, Zhang J, Zhou DW, Colard-Itté JR, Dattler D, Çolak A, Hoth M, García AJ, Qu B, Bennewitz R, Giuseppone N, Del Campo A. Optoregulated force application to cellular receptors using molecular motors. Nat Commun 2021; 12:3580. [PMID: 34117256 PMCID: PMC8196032 DOI: 10.1038/s41467-021-23815-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/13/2021] [Indexed: 01/16/2023] Open
Abstract
Progress in our understanding of mechanotransduction events requires noninvasive methods for the manipulation of forces at molecular scale in physiological environments. Inspired by cellular mechanisms for force application (i.e. motor proteins pulling on cytoskeletal fibers), we present a unique molecular machine that can apply forces at cell-matrix and cell-cell junctions using light as an energy source. The key actuator is a light-driven rotatory molecular motor linked to polymer chains, which is intercalated between a membrane receptor and an engineered biointerface. The light-driven actuation of the molecular motor is converted in mechanical twisting of the entangled polymer chains, which will in turn effectively “pull” on engaged cell membrane receptors (e.g., integrins, T cell receptors) within the illuminated area. Applied forces have physiologically-relevant magnitude and occur at time scales within the relevant ranges for mechanotransduction at cell-friendly exposure conditions, as demonstrated in force-dependent focal adhesion maturation and T cell activation experiments. Our results reveal the potential of nanomotors for the manipulation of living cells at the molecular scale and demonstrate a functionality which at the moment cannot be achieved by other technologies for force application. Molecular scale force application in physiological environments is important for studying mechanotransduction. Here, the authors use a molecular machine to apply forces at cell-matrix and cell-cell junctions using light to trigger twisting actuation which then pulls on cell membrane receptors.
Collapse
Affiliation(s)
- Yijun Zheng
- INM - Leibniz Institute for New Materials, Saarbrücken, Germany
| | | | - Renping Zhao
- Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany
| | - Johanna Blass
- INM - Leibniz Institute for New Materials, Saarbrücken, Germany
| | - Jingnan Zhang
- INM - Leibniz Institute for New Materials, Saarbrücken, Germany
| | - Dennis W Zhou
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.,Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jean-Rémy Colard-Itté
- SAMS Research Group, Institut Charles Sadron, University of Strasbourg - CNRS, Strasbourg, France
| | - Damien Dattler
- SAMS Research Group, Institut Charles Sadron, University of Strasbourg - CNRS, Strasbourg, France
| | - Arzu Çolak
- INM - Leibniz Institute for New Materials, Saarbrücken, Germany
| | - Markus Hoth
- Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany
| | - Andrés J García
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.,Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Bin Qu
- INM - Leibniz Institute for New Materials, Saarbrücken, Germany.,Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany
| | - Roland Bennewitz
- INM - Leibniz Institute for New Materials, Saarbrücken, Germany.,Saarland University, Physics Department, Saarbrücken, Germany
| | - Nicolas Giuseppone
- SAMS Research Group, Institut Charles Sadron, University of Strasbourg - CNRS, Strasbourg, France
| | - Aránzazu Del Campo
- INM - Leibniz Institute for New Materials, Saarbrücken, Germany. .,Saarland University, Chemistry Department, Saarbrücken, Germany.
| |
Collapse
|
4
|
Khan ES, Sankaran S, Paez JI, Muth C, Han MKL, del Campo A. Photoactivatable Hsp47: A Tool to Regulate Collagen Secretion and Assembly. Adv Sci (Weinh) 2019; 6:1801982. [PMID: 31065523 PMCID: PMC6498102 DOI: 10.1002/advs.201801982] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 02/13/2019] [Indexed: 06/09/2023]
Abstract
Collagen is the most abundant structural protein in mammals and is crucial for the mechanical integrity of tissues. Hsp47, an endoplasmic reticulum resident collagen-specific chaperone, is involved in collagen biosynthesis and plays a fundamental role in the folding, stability, and intracellular transport of procollagen triple helices. This work reports on a photoactivatable derivative of Hsp47 that allows regulation of collagen biosynthesis within mammalian cells using light. Photoactivatable Hsp47 contains a non-natural light-responsive tyrosine (o-nitro benzyl tyrosine (ONBY)) at Tyr383 position of the protein sequence. This mutation renders Hsp47 inactive toward collagen binding. The inactive, photoactivatable protein is easily uptaken by cells within a few minutes of incubation, and accumulated at the endoplasmic reticulum via retrograde KDEL receptor-mediated uptake. Upon light exposure, the photoactivatable Hsp47 turns into functional Hsp47 in situ. The increased intracellular concentration of Hsp47 results in stimulated secretion of collagen. The ability to promote collagen synthesis on demand, with spatiotemporal resolution, and in diseased state cells is demonstrated in vitro. It is envisioned that photoactivatable Hsp47 allows unprecedented fundamental studies of collagen biosynthesis, matrix biology, and inspires new therapeutic concepts in biomedicine and tissue regeneration.
Collapse
Affiliation(s)
- Essak S. Khan
- INM‐Leibniz Institute for New MaterialsCampus D2 2,66123SaarbrückenGermany
- Chemistry DepartmentSaarland University66123SaarbrückenGermany
| | | | - Julieta I. Paez
- INM‐Leibniz Institute for New MaterialsCampus D2 2,66123SaarbrückenGermany
| | - Christina Muth
- INM‐Leibniz Institute for New MaterialsCampus D2 2,66123SaarbrückenGermany
| | - Mitchell K. L. Han
- INM‐Leibniz Institute for New MaterialsCampus D2 2,66123SaarbrückenGermany
| | - Aránzazu del Campo
- INM‐Leibniz Institute for New MaterialsCampus D2 2,66123SaarbrückenGermany
- Chemistry DepartmentSaarland University66123SaarbrückenGermany
| |
Collapse
|
5
|
Abstract
The formation of multicellular tissues during development is governed by mechanical forces that drive cell shape and tissue architecture. Protein complexes at sites of adhesion to the extracellular matrix (ECM) and cell neighbors, not only transmit these mechanical forces, but also allow cells to respond to changes in force by inducing biochemical feedback pathways. Such force-induced signaling processes are termed mechanotransduction. Vinculin is a central protein in mechanotransduction that in both integrin-mediated cell-ECM and cadherin-mediated cell-cell adhesions mediates force-induced cytoskeletal remodeling and adhesion strengthening. Vinculin was found to be important for the integrity and remodeling of epithelial tissues in cell culture models and could therefore be expected to be of broad importance in epithelial morphogenesis in vivo. Besides a function in mouse heart development, however, the importance of vinculin in morphogenesis of other vertebrate tissues has remained unclear. To investigate this further, we knocked out vinculin functioning in zebrafish, which contain two fully functional isoforms designated as vinculin A and vinculin B that both show high sequence conservation with higher vertebrates. Using TALEN and CRISPR-Cas gene editing technology we generated vinculin-deficient zebrafish. While single vinculin A mutants are viable and able to reproduce, additional loss of zygotic vinculin B was lethal after embryonic stages. Remarkably, vinculin-deficient embryos do not show major developmental defects, apart from mild pericardial edemas. These results lead to the conclusion that vinculin is not of broad importance for the development and morphogenesis of zebrafish tissues.
Collapse
Affiliation(s)
- Mitchell K. L. Han
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Gerard N. M. van der Krogt
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Johan de Rooij
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
| |
Collapse
|
6
|
Han MKL, Hoijman E, Nöel E, Garric L, Bakkers J, de Rooij J. αE-catenin-dependent mechanotransduction is essential for proper convergent extension in zebrafish. Biol Open 2016; 5:1461-1472. [PMID: 27612508 PMCID: PMC5087688 DOI: 10.1242/bio.021378] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cadherin complexes mediate cell-cell adhesion and are crucial for embryonic development. Besides their structural function, cadherin complexes also transduce tension across the junction-actomyosin axis into proportional biochemical responses. Central to this mechanotransduction is the stretching of the cadherin-F-actin-linker α-catenin, which opens its central domain for binding to effectors such as vinculin. Mechanical unfolding of α-catenin leads to force-dependent reinforcement of cadherin-based junctions as studied in cell culture. The importance of cadherin mechanotransduction for embryonic development has not been studied yet. Here we used TALEN-mediated gene disruption to perturb endogenous αE-catenin in zebrafish development. Zygotic α-catenin mutants fail to maintain their epithelial barrier, resulting in tissue rupturing. We then specifically disrupted mechanotransduction, while maintaining cadherin adhesion, by expressing an αE-catenin construct in which the mechanosensitive domain was perturbed. Expression of either wild-type or mechano-defective α-catenin fully rescues barrier function in α-catenin mutants; however, expression of mechano-defective α-catenin also induces convergence and extension defects. Specifically, the polarization of cadherin-dependent, lamellipodia-driven cell migration of the lateral mesoderm was lost. These results indicate that cadherin mechanotransduction is crucial for proper zebrafish morphogenesis, and uncover one of the essential processes affected by its perturbation. Summary: Cadherin adhesions transduce tension across the junction-actomyosin axis into proportional biochemical responses via α-catenin. Here we show for the first time how this function of the cadherin complex is important during zebrafish morphogenesis.
Collapse
Affiliation(s)
- Mitchell K L Han
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Universiteitsweg 100, Utrecht 3584CG, The Netherlands
| | - Esteban Hoijman
- The Hubrecht Institute for Developmental Biology and Stem Cell Research and University Medical Center Utrecht, Uppsalalaan 8, Utrecht 3584CT, The Netherlands
| | - Emily Nöel
- The Hubrecht Institute for Developmental Biology and Stem Cell Research and University Medical Center Utrecht, Uppsalalaan 8, Utrecht 3584CT, The Netherlands
| | - Laurence Garric
- The Hubrecht Institute for Developmental Biology and Stem Cell Research and University Medical Center Utrecht, Uppsalalaan 8, Utrecht 3584CT, The Netherlands
| | - Jeroen Bakkers
- The Hubrecht Institute for Developmental Biology and Stem Cell Research and University Medical Center Utrecht, Uppsalalaan 8, Utrecht 3584CT, The Netherlands Department of Medical Physiology, University Medical Center Utrecht, Yalelaan 50, Utrecht 3584 CM, The Netherlands
| | - Johan de Rooij
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Universiteitsweg 100, Utrecht 3584CG, The Netherlands
| |
Collapse
|
7
|
Han MKL, de Rooij J. Converging and Unique Mechanisms of Mechanotransduction at Adhesion Sites. Trends Cell Biol 2016; 26:612-623. [PMID: 27036655 DOI: 10.1016/j.tcb.2016.03.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 12/31/2022]
Abstract
The molecular mechanisms by which physical forces control tissue development are beginning to be elucidated. Sites of adhesion between both cells and the extracellular environment [extracellular matrix (ECM) or neighboring cells] contain protein complexes capable of sensing fluctuations in tensile forces. Tension-dependent changes in the dynamics and composition of these complexes mark the transformation of physical input into biochemical signals that defines mechanotransduction. It is becoming apparent that, although the core constituents of these different adhesions are distinct, principles and proteins involved in mechanotransduction are conserved. Here, we discuss the current knowledge of overlapping and distinct aspects of mechanotransduction between integrin and cadherin adhesion complexes.
Collapse
Affiliation(s)
- Mitchell K L Han
- Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Stratenum 3.231, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Johan de Rooij
- Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Stratenum 3.231, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands.
| |
Collapse
|
8
|
Lee AY, St Onge RP, Proctor MJ, Wallace IM, Nile AH, Spagnuolo PA, Jitkova Y, Gronda M, Wu Y, Kim MK, Cheung-Ong K, Torres NP, Spear ED, Han MKL, Schlecht U, Suresh S, Duby G, Heisler LE, Surendra A, Fung E, Urbanus ML, Gebbia M, Lissina E, Miranda M, Chiang JH, Aparicio AM, Zeghouf M, Davis RW, Cherfils J, Boutry M, Kaiser CA, Cummins CL, Trimble WS, Brown GW, Schimmer AD, Bankaitis VA, Nislow C, Bader GD, Giaever G. Mapping the cellular response to small molecules using chemogenomic fitness signatures. Science 2014; 344:208-11. [PMID: 24723613 DOI: 10.1126/science.1250217] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Genome-wide characterization of the in vivo cellular response to perturbation is fundamental to understanding how cells survive stress. Identifying the proteins and pathways perturbed by small molecules affects biology and medicine by revealing the mechanisms of drug action. We used a yeast chemogenomics platform that quantifies the requirement for each gene for resistance to a compound in vivo to profile 3250 small molecules in a systematic and unbiased manner. We identified 317 compounds that specifically perturb the function of 121 genes and characterized the mechanism of specific compounds. Global analysis revealed that the cellular response to small molecules is limited and described by a network of 45 major chemogenomic signatures. Our results provide a resource for the discovery of functional interactions among genes, chemicals, and biological processes.
Collapse
Affiliation(s)
- Anna Y Lee
- The Donnelly Centre, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Wallace IM, Urbanus ML, Luciani GM, Burns AR, Han MKL, Wang H, Arora K, Heisler LE, Proctor M, St Onge RP, Roemer T, Roy PJ, Cummins CL, Bader GD, Nislow C, Giaever G. Compound prioritization methods increase rates of chemical probe discovery in model organisms. ACTA ACUST UNITED AC 2012; 18:1273-83. [PMID: 22035796 DOI: 10.1016/j.chembiol.2011.07.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 06/29/2011] [Accepted: 07/15/2011] [Indexed: 11/30/2022]
Abstract
Preselection of compounds that are more likely to induce a phenotype can increase the efficiency and reduce the costs for model organism screening. To identify such molecules, we screened ~81,000 compounds in Saccharomyces cerevisiae and identified ~7500 that inhibit cell growth. Screening these growth-inhibitory molecules across a diverse panel of model organisms resulted in an increased phenotypic hit-rate. These data were used to build a model to predict compounds that inhibit yeast growth. Empirical and in silico application of the model enriched the discovery of bioactive compounds in diverse model organisms. To demonstrate the potential of these molecules as lead chemical probes, we used chemogenomic profiling in yeast and identified specific inhibitors of lanosterol synthase and of stearoyl-CoA 9-desaturase. As community resources, the ~7500 growth-inhibitory molecules have been made commercially available and the computational model and filter used are provided.
Collapse
Affiliation(s)
- Iain M Wallace
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Canals M, Scholten DJ, de Munnik S, Han MKL, Smit MJ, Leurs R. Ubiquitination of CXCR7 controls receptor trafficking. PLoS One 2012; 7:e34192. [PMID: 22457824 PMCID: PMC3311620 DOI: 10.1371/journal.pone.0034192] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 02/28/2012] [Indexed: 12/21/2022] Open
Abstract
The chemokine receptor CXCR7 binds CXCL11 and CXCL12 with high affinity, chemokines that were previously thought to bind exclusively to CXCR4 and CXCR3, respectively. Expression of CXCR7 has been associated with cardiac development as well as with tumor growth and progression. Despite having all the canonical features of G protein-coupled receptors (GPCRs), the signalling pathways following CXCR7 activation remain controversial, since unlike typical chemokine receptors, CXCR7 fails to activate Gαi-proteins. CXCR7 has recently been shown to interact with β-arrestins and such interaction has been suggested to be responsible for G protein-independent signals through ERK-1/2 phosphorylation. Signal transduction by CXCR7 is controlled at the membrane by the process of GPCR trafficking. In the present study we investigated the regulatory processes triggered by CXCR7 activation as well as the molecular interactions that participate in such processes. We show that, CXCR7 internalizes and recycles back to the cell surface after agonist exposure, and that internalization is not only β-arrestin-mediated but also dependent on the Serine/Threonine residues at the C-terminus of the receptor. Furthermore we describe, for the first time, the constitutive ubiquitination of CXCR7. Such ubiquitination is a key modification responsible for the correct trafficking of CXCR7 from and to the plasma membrane. Moreover, we found that CXCR7 is reversibly de-ubiquitinated upon treatment with CXCL12. Finally, we have also identified the Lysine residues at the C-terminus of CXCR7 to be essential for receptor cell surface delivery. Together these data demonstrate the differential regulation of CXCR7 compared to the related CXCR3 and CXCR4 receptors, and highlight the importance of understanding the molecular determinants responsible for this process.
Collapse
Affiliation(s)
- Meritxell Canals
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|