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HEY1 functions are regulated by its phosphorylation at Ser-68

HEY1 (hairy/enhancer-of-split related with YRPW motif 1) is a member of the basic helix–loop–helix-orange (bHLH-O) family of transcription repressors that mediate Notch signalling. HEY1 acts as a positive regulator of the tumour suppressor p53 via still unknown mechanisms. A MALDI-TOF/TOF MS analysi...

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Autores principales: López-Mateo, Irene, Arruabarrena-Aristorena, Amaia, Artaza-Irigaray, Cristina, López, Juan A., Calvo, Enrique, Belandia, Borja
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Portland Press Ltd. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5293587/
https://www.ncbi.nlm.nih.gov/pubmed/27129302
http://dx.doi.org/10.1042/BSR20160123
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author López-Mateo, Irene
Arruabarrena-Aristorena, Amaia
Artaza-Irigaray, Cristina
López, Juan A.
Calvo, Enrique
Belandia, Borja
author_facet López-Mateo, Irene
Arruabarrena-Aristorena, Amaia
Artaza-Irigaray, Cristina
López, Juan A.
Calvo, Enrique
Belandia, Borja
author_sort López-Mateo, Irene
collection PubMed
description HEY1 (hairy/enhancer-of-split related with YRPW motif 1) is a member of the basic helix–loop–helix-orange (bHLH-O) family of transcription repressors that mediate Notch signalling. HEY1 acts as a positive regulator of the tumour suppressor p53 via still unknown mechanisms. A MALDI-TOF/TOF MS analysis has uncovered a novel HEY1 regulatory phosphorylation event at Ser-68. Strikingly, this single phosphorylation event controls HEY1 stability and function: simulation of HEY1 Ser-68 phosphorylation increases HEY1 protein stability but inhibits its ability to enhance p53 transcriptional activity. Unlike wild-type HEY1, expression of the phosphomimetic mutant HEY1-S68D failed to induce p53-dependent cell cycle arrest and it did not sensitize U2OS cells to p53-activating chemotherapeutic drugs. We have identified two related kinases, STK38 (serine/threonine kinase 38) and STK38L (serine/threonine kinase 38 like), which interact with and phosphorylate HEY1 at Ser-68. HEY1 is phosphorylated at Ser-68 during mitosis and it accumulates in the centrosomes of mitotic cells, suggesting a possible integration of HEY1-dependent signalling in centrosome function. Moreover, HEY1 interacts with a subset of p53-activating ribosomal proteins. Ribosomal stress causes HEY1 relocalization from the nucleoplasm to perinucleolar structures termed nucleolar caps. HEY1 interacts physically with at least one of the ribosomal proteins, RPL11, and both proteins cooperate in the inhibition of MDM2-mediated p53 degradation resulting in a synergistic positive effect on p53 transcriptional activity. HEY1 itself also interacts directly with MDM2 and it is subjected to MDM2-mediated degradation. Simulation of HEY1 Ser-68 phosphorylation prevents its interaction with p53, RPL11 and MDM2 and abolishes HEY1 migration to nucleolar caps upon ribosomal stress. Our findings uncover a novel mechanism for cross-talk between Notch signalling and nucleolar stress.
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spelling pubmed-52935872017-02-14 HEY1 functions are regulated by its phosphorylation at Ser-68 López-Mateo, Irene Arruabarrena-Aristorena, Amaia Artaza-Irigaray, Cristina López, Juan A. Calvo, Enrique Belandia, Borja Biosci Rep Original Papers HEY1 (hairy/enhancer-of-split related with YRPW motif 1) is a member of the basic helix–loop–helix-orange (bHLH-O) family of transcription repressors that mediate Notch signalling. HEY1 acts as a positive regulator of the tumour suppressor p53 via still unknown mechanisms. A MALDI-TOF/TOF MS analysis has uncovered a novel HEY1 regulatory phosphorylation event at Ser-68. Strikingly, this single phosphorylation event controls HEY1 stability and function: simulation of HEY1 Ser-68 phosphorylation increases HEY1 protein stability but inhibits its ability to enhance p53 transcriptional activity. Unlike wild-type HEY1, expression of the phosphomimetic mutant HEY1-S68D failed to induce p53-dependent cell cycle arrest and it did not sensitize U2OS cells to p53-activating chemotherapeutic drugs. We have identified two related kinases, STK38 (serine/threonine kinase 38) and STK38L (serine/threonine kinase 38 like), which interact with and phosphorylate HEY1 at Ser-68. HEY1 is phosphorylated at Ser-68 during mitosis and it accumulates in the centrosomes of mitotic cells, suggesting a possible integration of HEY1-dependent signalling in centrosome function. Moreover, HEY1 interacts with a subset of p53-activating ribosomal proteins. Ribosomal stress causes HEY1 relocalization from the nucleoplasm to perinucleolar structures termed nucleolar caps. HEY1 interacts physically with at least one of the ribosomal proteins, RPL11, and both proteins cooperate in the inhibition of MDM2-mediated p53 degradation resulting in a synergistic positive effect on p53 transcriptional activity. HEY1 itself also interacts directly with MDM2 and it is subjected to MDM2-mediated degradation. Simulation of HEY1 Ser-68 phosphorylation prevents its interaction with p53, RPL11 and MDM2 and abolishes HEY1 migration to nucleolar caps upon ribosomal stress. Our findings uncover a novel mechanism for cross-talk between Notch signalling and nucleolar stress. Portland Press Ltd. 2016-06-03 /pmc/articles/PMC5293587/ /pubmed/27129302 http://dx.doi.org/10.1042/BSR20160123 Text en © 2016 The Author(s) http://creativecommons.org/licenses/by/4.0/ This is an open access article published by Portland Press Limited on behalf of the Biochemical Society and distributed under the Creative Commons Attribution Licence 4.0 (CC BY) (http://creativecommons.org/licenses/by/4.0/) .
spellingShingle Original Papers
López-Mateo, Irene
Arruabarrena-Aristorena, Amaia
Artaza-Irigaray, Cristina
López, Juan A.
Calvo, Enrique
Belandia, Borja
HEY1 functions are regulated by its phosphorylation at Ser-68
title HEY1 functions are regulated by its phosphorylation at Ser-68
title_full HEY1 functions are regulated by its phosphorylation at Ser-68
title_fullStr HEY1 functions are regulated by its phosphorylation at Ser-68
title_full_unstemmed HEY1 functions are regulated by its phosphorylation at Ser-68
title_short HEY1 functions are regulated by its phosphorylation at Ser-68
title_sort hey1 functions are regulated by its phosphorylation at ser-68
topic Original Papers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5293587/
https://www.ncbi.nlm.nih.gov/pubmed/27129302
http://dx.doi.org/10.1042/BSR20160123
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