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Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme
PPP-family phosphatases such as PP1 have little intrinsic specificity. Cofactors can target PP1 to substrates or subcellular locations, but it remains unclear how they might confer sequence-specificity on PP1. The cytoskeletal regulator Phactr1 is a neuronally enriched PP1 cofactor that is controlle...
Autores principales: | , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7599070/ https://www.ncbi.nlm.nih.gov/pubmed/32975518 http://dx.doi.org/10.7554/eLife.61509 |
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author | Fedoryshchak, Roman O Přechová, Magdalena Butler, Abbey M Lee, Rebecca O'Reilly, Nicola Flynn, Helen R Snijders, Ambrosius P Eder, Noreen Ultanir, Sila Mouilleron, Stephane Treisman, Richard |
author_facet | Fedoryshchak, Roman O Přechová, Magdalena Butler, Abbey M Lee, Rebecca O'Reilly, Nicola Flynn, Helen R Snijders, Ambrosius P Eder, Noreen Ultanir, Sila Mouilleron, Stephane Treisman, Richard |
author_sort | Fedoryshchak, Roman O |
collection | PubMed |
description | PPP-family phosphatases such as PP1 have little intrinsic specificity. Cofactors can target PP1 to substrates or subcellular locations, but it remains unclear how they might confer sequence-specificity on PP1. The cytoskeletal regulator Phactr1 is a neuronally enriched PP1 cofactor that is controlled by G-actin. Structural analysis showed that Phactr1 binding remodels PP1's hydrophobic groove, creating a new composite surface adjacent to the catalytic site. Using phosphoproteomics, we identified mouse fibroblast and neuronal Phactr1/PP1 substrates, which include cytoskeletal components and regulators. We determined high-resolution structures of Phactr1/PP1 bound to the dephosphorylated forms of its substrates IRSp53 and spectrin αII. Inversion of the phosphate in these holoenzyme-product complexes supports the proposed PPP-family catalytic mechanism. Substrate sequences C-terminal to the dephosphorylation site make intimate contacts with the composite Phactr1/PP1 surface, which are required for efficient dephosphorylation. Sequence specificity explains why Phactr1/PP1 exhibits orders-of-magnitude enhanced reactivity towards its substrates, compared to apo-PP1 or other PP1 holoenzymes. |
format | Online Article Text |
id | pubmed-7599070 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-75990702020-11-02 Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme Fedoryshchak, Roman O Přechová, Magdalena Butler, Abbey M Lee, Rebecca O'Reilly, Nicola Flynn, Helen R Snijders, Ambrosius P Eder, Noreen Ultanir, Sila Mouilleron, Stephane Treisman, Richard eLife Biochemistry and Chemical Biology PPP-family phosphatases such as PP1 have little intrinsic specificity. Cofactors can target PP1 to substrates or subcellular locations, but it remains unclear how they might confer sequence-specificity on PP1. The cytoskeletal regulator Phactr1 is a neuronally enriched PP1 cofactor that is controlled by G-actin. Structural analysis showed that Phactr1 binding remodels PP1's hydrophobic groove, creating a new composite surface adjacent to the catalytic site. Using phosphoproteomics, we identified mouse fibroblast and neuronal Phactr1/PP1 substrates, which include cytoskeletal components and regulators. We determined high-resolution structures of Phactr1/PP1 bound to the dephosphorylated forms of its substrates IRSp53 and spectrin αII. Inversion of the phosphate in these holoenzyme-product complexes supports the proposed PPP-family catalytic mechanism. Substrate sequences C-terminal to the dephosphorylation site make intimate contacts with the composite Phactr1/PP1 surface, which are required for efficient dephosphorylation. Sequence specificity explains why Phactr1/PP1 exhibits orders-of-magnitude enhanced reactivity towards its substrates, compared to apo-PP1 or other PP1 holoenzymes. eLife Sciences Publications, Ltd 2020-09-25 /pmc/articles/PMC7599070/ /pubmed/32975518 http://dx.doi.org/10.7554/eLife.61509 Text en © 2020, Fedoryshchak et al http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Biochemistry and Chemical Biology Fedoryshchak, Roman O Přechová, Magdalena Butler, Abbey M Lee, Rebecca O'Reilly, Nicola Flynn, Helen R Snijders, Ambrosius P Eder, Noreen Ultanir, Sila Mouilleron, Stephane Treisman, Richard Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme |
title | Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme |
title_full | Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme |
title_fullStr | Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme |
title_full_unstemmed | Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme |
title_short | Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme |
title_sort | molecular basis for substrate specificity of the phactr1/pp1 phosphatase holoenzyme |
topic | Biochemistry and Chemical Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7599070/ https://www.ncbi.nlm.nih.gov/pubmed/32975518 http://dx.doi.org/10.7554/eLife.61509 |
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