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Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication

Merkel Cell Polyomavirus (MCPyV) was recently discovered as a novel human polyomavirus that is associated with ~80% of Merkel Cell Carcinomas. The Large Tumor antigen (LT) is an early viral protein which has a variety of functions, including manipulation of the cell cycle and initiating viral DNA re...

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Autores principales: Diaz, Jason, Wang, Xin, Tsang, Sabrina H., Jiao, Jing, You, Jianxin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190550/
https://www.ncbi.nlm.nih.gov/pubmed/25006834
http://dx.doi.org/10.3390/cancers6031464
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author Diaz, Jason
Wang, Xin
Tsang, Sabrina H.
Jiao, Jing
You, Jianxin
author_facet Diaz, Jason
Wang, Xin
Tsang, Sabrina H.
Jiao, Jing
You, Jianxin
author_sort Diaz, Jason
collection PubMed
description Merkel Cell Polyomavirus (MCPyV) was recently discovered as a novel human polyomavirus that is associated with ~80% of Merkel Cell Carcinomas. The Large Tumor antigen (LT) is an early viral protein which has a variety of functions, including manipulation of the cell cycle and initiating viral DNA replication. Phosphorylation plays a critical regulatory role for polyomavirus LT proteins, but no investigation of MCPyV LT phosphorylation has been performed to date. In this report mass spectrometry analysis reveals three unique phosphorylation sites: T271, T297 and T299. In vivo replication assays confirm that phosphorylation of T271 does not play a role in viral replication, while modification at T297 and T299 have dramatic and opposing effects on LT’s ability to initiate replication from the viral origin. We test these mutants for their ability to bind, unwind, and act as a functional helicase at the viral origin. These studies provide a framework for understanding how phosphorylation of LT may dynamically regulate viral replication. Although the natural host cell of MCPyV has not yet been established, this work provides a foundation for understanding how LT activity is regulated and provides tools for better exploring this regulation in both natural host cells and Merkel cells.
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spelling pubmed-41905502014-10-09 Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication Diaz, Jason Wang, Xin Tsang, Sabrina H. Jiao, Jing You, Jianxin Cancers (Basel) Article Merkel Cell Polyomavirus (MCPyV) was recently discovered as a novel human polyomavirus that is associated with ~80% of Merkel Cell Carcinomas. The Large Tumor antigen (LT) is an early viral protein which has a variety of functions, including manipulation of the cell cycle and initiating viral DNA replication. Phosphorylation plays a critical regulatory role for polyomavirus LT proteins, but no investigation of MCPyV LT phosphorylation has been performed to date. In this report mass spectrometry analysis reveals three unique phosphorylation sites: T271, T297 and T299. In vivo replication assays confirm that phosphorylation of T271 does not play a role in viral replication, while modification at T297 and T299 have dramatic and opposing effects on LT’s ability to initiate replication from the viral origin. We test these mutants for their ability to bind, unwind, and act as a functional helicase at the viral origin. These studies provide a framework for understanding how phosphorylation of LT may dynamically regulate viral replication. Although the natural host cell of MCPyV has not yet been established, this work provides a foundation for understanding how LT activity is regulated and provides tools for better exploring this regulation in both natural host cells and Merkel cells. MDPI 2014-07-08 /pmc/articles/PMC4190550/ /pubmed/25006834 http://dx.doi.org/10.3390/cancers6031464 Text en © 2014 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Diaz, Jason
Wang, Xin
Tsang, Sabrina H.
Jiao, Jing
You, Jianxin
Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication
title Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication
title_full Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication
title_fullStr Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication
title_full_unstemmed Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication
title_short Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication
title_sort phosphorylation of large t antigen regulates merkel cell polyomavirus replication
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190550/
https://www.ncbi.nlm.nih.gov/pubmed/25006834
http://dx.doi.org/10.3390/cancers6031464
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