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E50K-OPTN-Induced Retinal Cell Death Involves the Rab GTPase-Activating Protein, TBC1D17 Mediated Block in Autophagy

The protein optineurin coded by OPTN gene is involved in several functions including regulation of endocytic trafficking, autophagy and signal transduction. Certain missense mutations in the gene OPTN cause normal tension glaucoma. A glaucoma-causing mutant of optineurin, E50K, induces death selecti...

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Autores principales: Chalasani, Madhavi Latha Somaraju, Kumari, Asha, Radha, Vegesna, Swarup, Ghanshyam
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3994150/
https://www.ncbi.nlm.nih.gov/pubmed/24752605
http://dx.doi.org/10.1371/journal.pone.0095758
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author Chalasani, Madhavi Latha Somaraju
Kumari, Asha
Radha, Vegesna
Swarup, Ghanshyam
author_facet Chalasani, Madhavi Latha Somaraju
Kumari, Asha
Radha, Vegesna
Swarup, Ghanshyam
author_sort Chalasani, Madhavi Latha Somaraju
collection PubMed
description The protein optineurin coded by OPTN gene is involved in several functions including regulation of endocytic trafficking, autophagy and signal transduction. Certain missense mutations in the gene OPTN cause normal tension glaucoma. A glaucoma-causing mutant of optineurin, E50K, induces death selectively in retinal cells. This mutant induces defective endocytic recycling of transferrin receptor by causing inactivation of Rab8 mediated by the GTPase-activating protein, TBC1D17. Here, we have explored the mechanism of E50K-induced cell death. E50K-OPTN-induced cell death was inhibited by co-expression of a catalytically inactive mutant of TBC1D17 and also by shRNA mediated knockdown of TBC1D17. Endogenous TBC1D17 colocalized with E50K-OPTN in vesicular structures. Co-expression of transferrin receptor partially protected against E50K-induced cell death. Overexpression of the E50K-OPTN but not WT-OPTN inhibited autophagy flux. Treatment of cells with rapamycin, an inducer of autophagy, reduced E50K-OPTN-induced cell death. An LC3-binding-defective mutant of E50K-OPTN showed reduced cell death, further suggesting the involvement of autophagy. TBC1D17 localized to autophagosomes and inhibited autophagy flux dependent on its catalytic activity. Knockdown of TBC1D17 rescued cells from E50K-mediated inhibition of autophagy flux. Overall, our results suggest that E50K mutant induced death of retinal cells involves impaired autophagy as well as impaired transferrin receptor function. TBC1D17, a GTPase-activating protein for Rab GTPases, plays a crucial role in E50K-induced impaired autophagy and cell death.
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spelling pubmed-39941502014-04-25 E50K-OPTN-Induced Retinal Cell Death Involves the Rab GTPase-Activating Protein, TBC1D17 Mediated Block in Autophagy Chalasani, Madhavi Latha Somaraju Kumari, Asha Radha, Vegesna Swarup, Ghanshyam PLoS One Research Article The protein optineurin coded by OPTN gene is involved in several functions including regulation of endocytic trafficking, autophagy and signal transduction. Certain missense mutations in the gene OPTN cause normal tension glaucoma. A glaucoma-causing mutant of optineurin, E50K, induces death selectively in retinal cells. This mutant induces defective endocytic recycling of transferrin receptor by causing inactivation of Rab8 mediated by the GTPase-activating protein, TBC1D17. Here, we have explored the mechanism of E50K-induced cell death. E50K-OPTN-induced cell death was inhibited by co-expression of a catalytically inactive mutant of TBC1D17 and also by shRNA mediated knockdown of TBC1D17. Endogenous TBC1D17 colocalized with E50K-OPTN in vesicular structures. Co-expression of transferrin receptor partially protected against E50K-induced cell death. Overexpression of the E50K-OPTN but not WT-OPTN inhibited autophagy flux. Treatment of cells with rapamycin, an inducer of autophagy, reduced E50K-OPTN-induced cell death. An LC3-binding-defective mutant of E50K-OPTN showed reduced cell death, further suggesting the involvement of autophagy. TBC1D17 localized to autophagosomes and inhibited autophagy flux dependent on its catalytic activity. Knockdown of TBC1D17 rescued cells from E50K-mediated inhibition of autophagy flux. Overall, our results suggest that E50K mutant induced death of retinal cells involves impaired autophagy as well as impaired transferrin receptor function. TBC1D17, a GTPase-activating protein for Rab GTPases, plays a crucial role in E50K-induced impaired autophagy and cell death. Public Library of Science 2014-04-21 /pmc/articles/PMC3994150/ /pubmed/24752605 http://dx.doi.org/10.1371/journal.pone.0095758 Text en © 2014 Chalasani et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Chalasani, Madhavi Latha Somaraju
Kumari, Asha
Radha, Vegesna
Swarup, Ghanshyam
E50K-OPTN-Induced Retinal Cell Death Involves the Rab GTPase-Activating Protein, TBC1D17 Mediated Block in Autophagy
title E50K-OPTN-Induced Retinal Cell Death Involves the Rab GTPase-Activating Protein, TBC1D17 Mediated Block in Autophagy
title_full E50K-OPTN-Induced Retinal Cell Death Involves the Rab GTPase-Activating Protein, TBC1D17 Mediated Block in Autophagy
title_fullStr E50K-OPTN-Induced Retinal Cell Death Involves the Rab GTPase-Activating Protein, TBC1D17 Mediated Block in Autophagy
title_full_unstemmed E50K-OPTN-Induced Retinal Cell Death Involves the Rab GTPase-Activating Protein, TBC1D17 Mediated Block in Autophagy
title_short E50K-OPTN-Induced Retinal Cell Death Involves the Rab GTPase-Activating Protein, TBC1D17 Mediated Block in Autophagy
title_sort e50k-optn-induced retinal cell death involves the rab gtpase-activating protein, tbc1d17 mediated block in autophagy
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3994150/
https://www.ncbi.nlm.nih.gov/pubmed/24752605
http://dx.doi.org/10.1371/journal.pone.0095758
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