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Dlg-1 Interacts With and Regulates the Activities of Fibroblast Growth Factor Receptors and EphA2 in the Mouse Lens

PURPOSE: We previously showed that Discs large-1 (Dlg-1) regulates lens fiber cell structure and the fibroblast growth factor receptor (Fgfr) signaling pathway, a pathway required for fiber cell differentiation. Herein, we investigated the mechanism through which Dlg-1 regulates Fgfr signaling. METH...

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Autores principales: Lee, SungKyoung, Shatadal, Shalini, Griep, Anne E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Association for Research in Vision and Ophthalmology 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4771194/
https://www.ncbi.nlm.nih.gov/pubmed/26906157
http://dx.doi.org/10.1167/iovs.15-17727
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author Lee, SungKyoung
Shatadal, Shalini
Griep, Anne E.
author_facet Lee, SungKyoung
Shatadal, Shalini
Griep, Anne E.
author_sort Lee, SungKyoung
collection PubMed
description PURPOSE: We previously showed that Discs large-1 (Dlg-1) regulates lens fiber cell structure and the fibroblast growth factor receptor (Fgfr) signaling pathway, a pathway required for fiber cell differentiation. Herein, we investigated the mechanism through which Dlg-1 regulates Fgfr signaling. METHODS: Immunofluorescence was used to measure levels of Fgfr1, Fgfr2, and activated Fgfr signaling intermediates, pErk and pAkt, in control and Dlg-1–deficient lenses that were haplodeficient for Fgfr1 or Fgfr2. Immunoblotting was used to measure levels of N-cadherin, EphA2, β-catenin, and tyrosine-phosphorylated EphA2, Fgfr1, Fgfr2, and Fgfr3 in cytoskeletal-associated and cytosolic fractions of control and Dlg-1–deficient lenses. Complex formation between Dlg-1, N-cadherin, β-catenin, Fgfr1, Fgfr2, Fgfr3, and EphA2 was assessed by coimmunoprecipitation. RESULTS: Lenses deficient for Dlg-1 and haplodeficient for Fgfr1 or Fgfr2 showed increased levels of Fgfr2 or Fgfr1, respectively. Levels of pErk and pAkt correlated with the level of Fgfr2. N-cadherin was reduced in the cytoskeletal-associated fraction and increased in the cytosolic fraction of Dlg-1–deficient lenses. Dlg-1 complexed with β-catenin, EphA2, Fgfr1, Fgfr2, and Fgfr3. EphA2 complexed with N-cadherin, β-catenin, Fgfr1, Fgfr2, and Fgfr3. Levels of these interactions were altered in Dlg-1–deficient lenses. Loss of Dlg-1 led to changes in Fgfr1, Fgfr2, Fgfr3, and EphA2 levels and to greater changes in the levels of their activation. CONCLUSIONS: Dlg-1 complexes with and regulates the activities of EphA2, Fgfr1, Fgfr2, and Fgfr3. As EphA2 contains a Psd95/Dlg/ZO-1 (PDZ) binding motif, whereas Fgfrs do not, we propose that the PDZ protein, Dlg-1, modulates Fgfr signaling through regulation of EphA2.
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spelling pubmed-47711942016-08-01 Dlg-1 Interacts With and Regulates the Activities of Fibroblast Growth Factor Receptors and EphA2 in the Mouse Lens Lee, SungKyoung Shatadal, Shalini Griep, Anne E. Invest Ophthalmol Vis Sci Lens PURPOSE: We previously showed that Discs large-1 (Dlg-1) regulates lens fiber cell structure and the fibroblast growth factor receptor (Fgfr) signaling pathway, a pathway required for fiber cell differentiation. Herein, we investigated the mechanism through which Dlg-1 regulates Fgfr signaling. METHODS: Immunofluorescence was used to measure levels of Fgfr1, Fgfr2, and activated Fgfr signaling intermediates, pErk and pAkt, in control and Dlg-1–deficient lenses that were haplodeficient for Fgfr1 or Fgfr2. Immunoblotting was used to measure levels of N-cadherin, EphA2, β-catenin, and tyrosine-phosphorylated EphA2, Fgfr1, Fgfr2, and Fgfr3 in cytoskeletal-associated and cytosolic fractions of control and Dlg-1–deficient lenses. Complex formation between Dlg-1, N-cadherin, β-catenin, Fgfr1, Fgfr2, Fgfr3, and EphA2 was assessed by coimmunoprecipitation. RESULTS: Lenses deficient for Dlg-1 and haplodeficient for Fgfr1 or Fgfr2 showed increased levels of Fgfr2 or Fgfr1, respectively. Levels of pErk and pAkt correlated with the level of Fgfr2. N-cadherin was reduced in the cytoskeletal-associated fraction and increased in the cytosolic fraction of Dlg-1–deficient lenses. Dlg-1 complexed with β-catenin, EphA2, Fgfr1, Fgfr2, and Fgfr3. EphA2 complexed with N-cadherin, β-catenin, Fgfr1, Fgfr2, and Fgfr3. Levels of these interactions were altered in Dlg-1–deficient lenses. Loss of Dlg-1 led to changes in Fgfr1, Fgfr2, Fgfr3, and EphA2 levels and to greater changes in the levels of their activation. CONCLUSIONS: Dlg-1 complexes with and regulates the activities of EphA2, Fgfr1, Fgfr2, and Fgfr3. As EphA2 contains a Psd95/Dlg/ZO-1 (PDZ) binding motif, whereas Fgfrs do not, we propose that the PDZ protein, Dlg-1, modulates Fgfr signaling through regulation of EphA2. The Association for Research in Vision and Ophthalmology 2016-02-23 2016-02 /pmc/articles/PMC4771194/ /pubmed/26906157 http://dx.doi.org/10.1167/iovs.15-17727 Text en http://creativecommons.org/licenses/by-nc-nd/4.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
spellingShingle Lens
Lee, SungKyoung
Shatadal, Shalini
Griep, Anne E.
Dlg-1 Interacts With and Regulates the Activities of Fibroblast Growth Factor Receptors and EphA2 in the Mouse Lens
title Dlg-1 Interacts With and Regulates the Activities of Fibroblast Growth Factor Receptors and EphA2 in the Mouse Lens
title_full Dlg-1 Interacts With and Regulates the Activities of Fibroblast Growth Factor Receptors and EphA2 in the Mouse Lens
title_fullStr Dlg-1 Interacts With and Regulates the Activities of Fibroblast Growth Factor Receptors and EphA2 in the Mouse Lens
title_full_unstemmed Dlg-1 Interacts With and Regulates the Activities of Fibroblast Growth Factor Receptors and EphA2 in the Mouse Lens
title_short Dlg-1 Interacts With and Regulates the Activities of Fibroblast Growth Factor Receptors and EphA2 in the Mouse Lens
title_sort dlg-1 interacts with and regulates the activities of fibroblast growth factor receptors and epha2 in the mouse lens
topic Lens
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4771194/
https://www.ncbi.nlm.nih.gov/pubmed/26906157
http://dx.doi.org/10.1167/iovs.15-17727
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