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Zhang L, Yu J, Zheng M, Zhen H, Xie Q, Zhang C, Zhou Z, Jin G. RAGA prevents tumor immune evasion of LUAD by promoting CD47 lysosome degradation. Commun Biol 2023; 6:211. [PMID: 36823443 PMCID: PMC9950044 DOI: 10.1038/s42003-023-04581-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 02/10/2023] [Indexed: 02/25/2023] Open
Abstract
CD47 is a macrophage-specific immune checkpoint protein acting by inhibiting phagocytosis. However, the underlying mechanism maintaining CD47 protein stability in cancer is not clear. Here we show that CD47 undergoes degradation via endocytosis/lysosome pathway. The lysosome protein RAGA interacts with and promotes CD47 lysosome localization and degradation. Disruption of RAGA blocks CD47 degradation, leading to CD47 accumulation, high plasma membrane/intracellular CD47 expression ratio and reduced phagocytic clearance of cancer cells. RAGA deficiency promotes tumor growth due to the accumulation of CD47, which sensitizes the tumor to CD47 blockade. Clinical analysis shows that RAGA and CD47 proteins are negatively correlated in lung adenocarcinoma patient samples. High RAGA protein level is related to longer patient survival. In addition, RAGAhighCD47low patients show the longest overall survival. Our study thereby not only reveals a mechanism by which RAGA regulates CD47 lysosome degradation, but also suggests RAGA is a potential diagnostic biomarker of lung adenocarcinoma.
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Affiliation(s)
- Lian Zhang
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
- College of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
| | - Jing Yu
- Department of Surgery Oncology, The Second People's Hospital of Neijiang, Neijiang, 641000, China
| | - Mingyue Zheng
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China
| | - Hui Zhen
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China
| | - Qingqiang Xie
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China
| | - Chundong Zhang
- Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing, 400016, China
| | - Zhongjun Zhou
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China.
| | - Guoxiang Jin
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China.
- Guangdong Provincial Geriatrics Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China.
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Lamb AK, Fernandez AN, Peersen OB, Di Pietro SM. The dynein light chain protein Tda2 functions as a dimerization engine to regulate actin capping protein during endocytosis. Mol Biol Cell 2021; 32:1459-1473. [PMID: 34081539 PMCID: PMC8351736 DOI: 10.1091/mbc.e21-01-0032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Clathrin- and actin-mediated endocytosis is a fundamental process in eukaryotic cells. Previously, we discovered Tda2 as a new yeast dynein light chain (DLC) that works with Aim21 to regulate actin assembly during endocytosis. Here we show Tda2 functions as a dimerization engine bringing two Aim21 molecules together using a novel binding surface different than the canonical DLC ligand binding groove. Point mutations on either protein that diminish the Tda2-Aim21 interaction in vitro cause the same in vivo phenotype as TDA2 deletion showing reduced actin capping protein (CP) recruitment and increased filamentous actin at endocytic sites. Remarkably, chemically induced dimerization of Aim21 rescues the endocytic phenotype of TDA2 deletion. We also uncovered a CP interacting motif in Aim21, expanding its function to a fundamental cellular pathway and showing such motif exists outside mammalian cells. Furthermore, specific disruption of this motif causes the same deficit of actin CP recruitment and increased filamentous actin at endocytic sites as AIM21 deletion. Thus, the data indicate the Tda2-Aim21 complex functions in actin assembly primarily through CP regulation. Collectively, our results provide a mechanistic view of the Tda2-Aim21 complex and its function in actin network regulation at endocytic sites.
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Affiliation(s)
- Andrew K Lamb
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870
| | - Andres N Fernandez
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870
| | - Olve B Peersen
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870
| | - Santiago M Di Pietro
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870
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Dumitru CA, Brouwer E, Stelzer T, Nocerino S, Rading S, Wilkens L, Sandalcioglu IE, Karsak M. Dynein Light Chain Protein Tctex1: A Novel Prognostic Marker and Molecular Mediator in Glioblastoma. Cancers (Basel) 2021; 13:cancers13112624. [PMID: 34071761 PMCID: PMC8199143 DOI: 10.3390/cancers13112624] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/20/2021] [Accepted: 05/24/2021] [Indexed: 11/25/2022] Open
Abstract
Simple Summary Glioblastoma (GBM) remains one of the deadliest solid cancers, with only a dismal proportion of GBM patients achieving 5-year survival. Thus, it is critical to identify molecular mechanisms that could be targeted by novel therapeutic approaches in this tumor type. Our study identified Tctex1/DYNLT1 as an independent prognostic marker for the overall survival of GBM patients. Importantly, Tctex1 promoted the aggressiveness of GBM cells by enhancing tumor proliferation and invasion. These effects of Tctex1 appeared to be modulated via phosphorylation of retinoblastoma protein (RB) and the release of matrix metalloprotease 2 (MMP2), respectively. As Tctex1 can potentially be inhibited in vivo, our study provides a rationale for novel, individualized therapeutic strategies in GBM patients. Abstract The purpose of this study was to determine the role of Tctex1 (DYNLT1, dynein light chain-1) in the pathophysiology of glioblastoma (GBM). To this end, we performed immunohistochemical analyses on tissues from GBM patients (n = 202). Tctex1 was additionally overexpressed in two different GBM cell lines, which were then evaluated in regard to their proliferative and invasive properties. We found that Tctex1 levels were significantly higher in GBM compared to healthy adjacent brain tissues. Furthermore, high Tctex1 expression was significantly associated with the short overall- (p = 0.002, log-rank) and progression-free (p = 0.028, log-rank) survival of GBM patients and was an independent predictor of poor overall survival in multivariate Cox-regression models. In vitro, Tctex1 promoted the metabolic activity, anchorage-independent growth and proliferation of GBM cells. This phenomenon was previously shown to occur via the phosphorylation of retinoblastoma protein (phospho-RB). Here, we found a direct and significant correlation between the levels of Tctex1 and phospho-RB (Ser807/801) in tissues from GBM patients (p = 0.007, Rho = 0.284, Spearman’s rank). Finally, Tctex1 enhanced the invasiveness of GBM cells and the release of pro-invasive matrix metalloprotease 2 (MMP2). These findings indicate that Tctex1 promotes GBM progression and therefore might be a useful therapeutic target in this type of cancer.
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Affiliation(s)
- Claudia Alexandra Dumitru
- Department of Neurosurgery, Otto-von-Guericke University, 39120 Magdeburg, Germany;
- Correspondence: (C.A.D.); (M.K.)
| | - Eileen Brouwer
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (E.B.); (T.S.); (S.N.); (S.R.)
| | - Tamina Stelzer
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (E.B.); (T.S.); (S.N.); (S.R.)
| | - Salvatore Nocerino
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (E.B.); (T.S.); (S.N.); (S.R.)
| | - Sebastian Rading
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (E.B.); (T.S.); (S.N.); (S.R.)
| | - Ludwig Wilkens
- Department of Pathology, Nordstadt Hospital Hannover, 30167 Hannover, Germany;
| | | | - Meliha Karsak
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (E.B.); (T.S.); (S.N.); (S.R.)
- Correspondence: (C.A.D.); (M.K.)
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Ismail OZ, Sriranganathan S, Zhang X, Bonventre JV, Zervos AS, Gunaratnam L. Tctex-1, a novel interaction partner of Kidney Injury Molecule-1, is required for efferocytosis. J Cell Physiol 2018; 233:6877-6895. [PMID: 29693725 DOI: 10.1002/jcp.26578] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 03/01/2018] [Indexed: 02/04/2023]
Abstract
Kidney injury molecule-1 (KIM-1) is a phosphatidylserine receptor that is specifically upregulated on proximal tubular epithelial cells (PTECs) during acute kidney injury and mitigates tissue damage by mediating efferocytosis (the phagocytic clearance of apoptotic cells). The signaling molecules that regulate efferocytosis in TECs are not well understood. Using a yeast two-hybrid screen, we identified the dynein light chain protein, Tctex-1, as a novel KIM-1-interacting protein. Immunoprecipitation and confocal imaging studies suggested that Tctex-1 associates with KIM-1 in cells at baseline, but, dissociates from KIM-1 within 90 min of initiation of efferocytosis. Interfering with actin or microtubule polymerization interestingly prevented the dissociation of KIM-1 from Tctex-1. Moreover, the subcellular localization of Tctex-1 changed from being microtubule-associated to mainly cytosolic upon expression of KIM-1. Short hairpin RNA-mediated silencing of endogenous Tctex-1 in cells significantly inhibited efferocytosis to levels comparable to that of knock down of KIM-1 in the same cells. Importantly, Tctex-1 was not involved in the delivery of KIM-1 to the cell-surface. On the other hand, KIM-1 expression significantly inhibited the phosphorylation of Tctex-1 at threonine 94 (T94), a post-translational modification which is known to disrupt the binding of Tctex-1 to dynein on microtubules. In keeping with this, we found that KIM-1 bound less efficiently to the phosphomimic (T94E) mutant of Tctex-1 compared to wild type Tctex-1. Surprisingly, expression of Tctex-1 T94E did not influence KIM-1-mediated efferocytosis. Our studies uncover a previously unknown role for Tctex-1 in KIM-1-dependent efferocytosis in epithelial cells.
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Affiliation(s)
- Ola Z Ismail
- Matthew Mailing Center for Translational Transplant Studies, London Health Sciences Center, Lawson Health Research Institute, London, Ontario, Canada
| | - Saranga Sriranganathan
- Matthew Mailing Center for Translational Transplant Studies, London Health Sciences Center, Lawson Health Research Institute, London, Ontario, Canada
| | - Xizhong Zhang
- Matthew Mailing Center for Translational Transplant Studies, London Health Sciences Center, Lawson Health Research Institute, London, Ontario, Canada
| | - Joseph V Bonventre
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Antonis S Zervos
- Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, Orlando, Florida
| | - Lakshman Gunaratnam
- Matthew Mailing Center for Translational Transplant Studies, London Health Sciences Center, Lawson Health Research Institute, London, Ontario, Canada.,Division of Nephrology, Department of Medicine, Schulich School of Medicine and Dentistry, London, Western University, Ontario, Canada
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Silencing of Tctex1 impairs autophagy lysosomal degradation of α-synuclein and cell viability. Neuroreport 2018; 29:385-392. [PMID: 29406369 DOI: 10.1097/wnr.0000000000000979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Tctex1 is an important element of the dynein motor unit in mammalian cells that helps move targets along microtubules and toward the centrosome for degradation. Here, we analyzed the role of Tctex1 in the α-synuclein autophagy-lysosome degradation pathway using Tctex1-siRNA in SH-SY5Y cells. Results showed that siRNA silencing of Tctex1 suppressed cellular viability and promoted cell apoptosis. Protein and mRNA expression of Tctex1 and dynein decreased after Tctex1 knockdown, whereas α-synuclein, LC3-II, and LAMP2 increased. Consistently, fluorescence intensity of Tctex1 was weaker in siRNA-Tctex1-transfected cells, and that of α-synuclein, LC3-II, and LAMP2 was increased. Tctex1 inhibition reduced cell viability and promoted apoptosis. These results show that Tctex1 plays an important role in α-synuclein autophagic degradation and in maintaining cellular homeostasis.
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Osseman Q, Gallucci L, Au S, Cazenave C, Berdance E, Blondot ML, Cassany A, Bégu D, Ragues J, Aknin C, Sominskaya I, Dishlers A, Rabe B, Anderson F, Panté N, Kann M. The chaperone dynein LL1 mediates cytoplasmic transport of empty and mature hepatitis B virus capsids. J Hepatol 2018; 68:441-448. [PMID: 29113909 DOI: 10.1016/j.jhep.2017.10.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 09/26/2017] [Accepted: 10/27/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Hepatitis B virus (HBV) has a DNA genome but replicates within the nucleus by reverse transcription of an RNA pregenome, which is converted to DNA in cytoplasmic capsids. Capsids in this compartment are correlated with inflammation and epitopes of the capsid protein core (Cp) are a major target for T cell-mediated immune responses. We investigated the mechanism of cytoplasmic capsid transport, which is important for infection but also for cytosolic capsid removal. METHODS We used virion-derived capsids containing mature rcDNA (matC) and empty capsids (empC). RNA-containing capsids (rnaC) were used as a control. The investigations comprised pull-down assays for identification of cellular interaction partners, immune fluorescence microscopy for their colocalization and electron microscopy after microinjection to determine their biological significance. RESULTS matC and empC underwent active transport through the cytoplasm towards the nucleus, while rnaC was poorly transported. We identified the dynein light chain LL1 as a functional interaction partner linking capsids to the dynein motor complex and showed that there is no compensatory transport pathway. Using capsid and dynein LL1 mutants we characterized the required domains on the capsid and LL1. CONCLUSIONS This is the first investigation on the detailed molecular mechanism of how matC pass the cytoplasm upon infection and how empC can be actively removed from the cytoplasm into the nucleus. Considering that hepatocytes with cytoplasmic capsids are better recognized by the T cells, we hypothesize that targeting capsid DynLL1-interaction will not only block HBV infection but also stimulate elimination of infected cells. LAY SUMMARY In this study, we identified the molecular details of HBV translocation through the cytoplasm. Our evidence offers a new drug target which could not only inhibit infection but also stimulate immune clearance of HBV infected cells.
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Affiliation(s)
- Quentin Osseman
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Lara Gallucci
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Shelly Au
- Department of Zoology, University of British Columbia Vancouver, B.C. V6T 1Z4, Canada
| | - Christian Cazenave
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Elodie Berdance
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Marie-Lise Blondot
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Aurélia Cassany
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Dominique Bégu
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Jessica Ragues
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Cindy Aknin
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | | | - Andris Dishlers
- Latvian Biomedical Research and Study Center, 1067 Riga, Latvia
| | - Birgit Rabe
- Institute of Medical Virology, University of Giessen, 35392 Giessen, Germany
| | - Fenja Anderson
- Institute of Medical Virology, University of Giessen, 35392 Giessen, Germany; Institute of Virology, Hannover Medical School, 30625 Hannover, Germany
| | - Nelly Panté
- Department of Zoology, University of British Columbia Vancouver, B.C. V6T 1Z4, Canada
| | - Michael Kann
- Univ. de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33076 Bordeaux, France; CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France; Institute of Medical Virology, University of Giessen, 35392 Giessen, Germany; CHU de Bordeaux, 33000 Bordeaux, France.
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Tctex1 plays a key role in the α-synuclein autophagy lysosomal degradation pathway. Neurosci Lett 2017; 661:90-95. [PMID: 28970129 DOI: 10.1016/j.neulet.2017.09.050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/04/2017] [Accepted: 09/25/2017] [Indexed: 11/23/2022]
Abstract
Tctex1 is an important structure of dynein light chain in mammalian cells, clarifying the role of Tctex1 in α-synuclein autophagy lysosomal degradation may offer insights into the formation of Lewy bodies and neuronal death. We constructed dsRED-N1-Tctex1 overexpression, pDsRED2-N1-Tctex1(T94E) mutation and transfected into SH-SY5Y cells. Relative protein expression was measured by Western Blot and mRNA levels were measured by real-time quantitative PCR. Confocal microscopy was used to observe their sublocalizations in cells. We found that: WST assay results show that cell activity decreased after Tctex1 mutation (T94E), while Tctex1 overexpression increased cell activity. In Tctex1 mutation transfected cell lines Tctex1 and dynein protein levels decreased; α-synuclein, LC3-II and LAMP2 protein increased. However, α-synuclein, LC3-II and LAMP2 proteins were reduced in Tctex1 overexpression cell lines, with the same trend was found in mRNA levels. In Tctex1 mutation transfected cell lines Tctex1 fluorescence intensity weakened; α-synuclein, LC3-II and LAMP2 fluorescence was enhanced, while α-synuclein, LC3-II and LAMP2 weakened in Tctex1 overexpressing cells. Our results suggest that Tctex1 mutants interference lead to Tctex1 downregulation and dysfunction. Tctex1 overexpression promoted autophagy lysosome fusion and effectively degraded α-synuclein with increased cell activity. Thus, Tctex1 plays an important role in α-synuclein autophagic degradation.
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Merino-Gracia J, Zamora-Carreras H, Bruix M, Rodríguez-Crespo I. Molecular Basis for the Protein Recognition Specificity of the Dynein Light Chain DYNLT1/Tctex1: CHARACTERIZATION OF THE INTERACTION WITH ACTIVIN RECEPTOR IIB. J Biol Chem 2016; 291:20962-20975. [PMID: 27502274 DOI: 10.1074/jbc.m116.736884] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Indexed: 01/19/2023] Open
Abstract
It has been suggested that DYNLT1, a dynein light chain known to bind to various cellular and viral proteins, can function both as a molecular clamp and as a microtubule-cargo adapter. Recent data have shown that the DYNLT1 homodimer binds to two dynein intermediate chains to subsequently link cargo proteins such as the guanine nucleotide exchange factor Lfc or the small GTPases RagA and Rab3D. Although over 20 DYNLT1-interacting proteins have been reported, the exact sequence requirements that enable their association to the canonical binding groove or to the secondary site within the DYNLT1 surface are unknown. We describe herein the sequence recognition properties of the hydrophobic groove of DYNLT1 known to accommodate dynein intermediate chain. Using a pepscan approach, we have substituted each amino acid within the interacting peptide for all 20 natural amino acids and identified novel binding sequences. Our data led us to propose activin receptor IIB as a novel DYNLT1 ligand and suggest that DYNLT1 functions as a molecular dimerization engine bringing together two receptor monomers in the cytoplasmic side of the membrane. In addition, we provide evidence regarding a dual binding mode adopted by certain interacting partners such as Lfc or the parathyroid hormone receptor. Finally, we have used NMR spectroscopy to obtain the solution structure of human DYNLT1 forming a complex with dynein intermediate chain of ∼74 kDa; it is the first mammalian structure available.
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Affiliation(s)
- Javier Merino-Gracia
- From the Departamento Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain and
| | - Héctor Zamora-Carreras
- Departamento Química Física Biológica, Instituto Química Física Rocasolano, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain
| | - Marta Bruix
- Departamento Química Física Biológica, Instituto Química Física Rocasolano, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain
| | - Ignacio Rodríguez-Crespo
- From the Departamento Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain and
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Merino-Gracia J, Costas-Insua C, Canales MÁ, Rodríguez-Crespo I. Insights into the C-terminal Peptide Binding Specificity of the PDZ Domain of Neuronal Nitric-oxide Synthase: CHARACTERIZATION OF THE INTERACTION WITH THE TIGHT JUNCTION PROTEIN CLAUDIN-3. J Biol Chem 2016; 291:11581-95. [PMID: 27030110 DOI: 10.1074/jbc.m116.724427] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Indexed: 11/06/2022] Open
Abstract
Neuronal nitric-oxide synthase, unlike its endothelial and inducible counterparts, displays a PDZ (PSD-95/Dlg/ZO-1) domain located at its N terminus involved in subcellular targeting. The C termini of various cellular proteins insert within the binding groove of this PDZ domain and determine the subcellular distribution of neuronal NOS (nNOS). The molecular mechanisms underlying these interactions are poorly understood because the PDZ domain of nNOS can apparently exhibit class I, class II, and class III binding specificity. In addition, it has been recently suggested that the PDZ domain of nNOS binds with very low affinity to the C termini of target proteins, and a necessary simultaneous lateral interaction must take place for binding to occur. We describe herein that the PDZ domain of nNOS can behave as a bona fide class III PDZ domain and bind to C-terminal sequences with acidic residues at the P-2 position with low micromolar binding constants. Binding to C-terminal sequences with a hydrophobic residue at the P-2 position plus an acidic residue at the P-3 position (class II) can also occur, although interactions involving residues extending up to the P-7 position mediate this type of binding. This promiscuous behavior also extends to its association to class I sequences, which must display a Glu residue at P-3 and a Thr residue at P-2 By means of site-directed mutagenesis and NMR spectroscopy, we have been able to identify the residues involved in each specific type of binding and rationalize the mechanisms used to recognize binding partners. Finally, we have analyzed the high affinity association of the PDZ domain of nNOS to claudin-3 and claudin-14, two tight junction tetraspan membrane proteins that are essential components of the paracellular barrier.
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Affiliation(s)
| | | | - María Ángeles Canales
- Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid 28040, Spain
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