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Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding

Mutations in myosin VI have been associated with autosomal-recessive (DFNB37) and autosomal-dominant (DFNA22) deafness in humans. Here, we characterise an myosin VI nonsense mutation (R1166X) that was identified in a family with hereditary hearing loss in Pakistan. This mutation leads to the deletio...

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Autores principales: Arden, Susan D., Tumbarello, David A., Butt, Tariq, Kendrick-Jones, John, Buss, Folma
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Portland Press Ltd. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5074368/
https://www.ncbi.nlm.nih.gov/pubmed/27474411
http://dx.doi.org/10.1042/BCJ20160571
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author Arden, Susan D.
Tumbarello, David A.
Butt, Tariq
Kendrick-Jones, John
Buss, Folma
author_facet Arden, Susan D.
Tumbarello, David A.
Butt, Tariq
Kendrick-Jones, John
Buss, Folma
author_sort Arden, Susan D.
collection PubMed
description Mutations in myosin VI have been associated with autosomal-recessive (DFNB37) and autosomal-dominant (DFNA22) deafness in humans. Here, we characterise an myosin VI nonsense mutation (R1166X) that was identified in a family with hereditary hearing loss in Pakistan. This mutation leads to the deletion of the C-terminal 120 amino acids of the myosin VI cargo-binding domain, which includes the WWY-binding motif for the adaptor proteins LMTK2, Tom1 as well as Dab2. Interestingly, compromising myosin VI vesicle-binding ability by expressing myosin VI with the R1166X mutation or with single point mutations in the adaptor-binding sites leads to increased F-actin binding of this myosin in vitro and in vivo. As our results highlight the importance of cargo attachment for regulating actin binding to the motor domain, we perform a detailed characterisation of adaptor protein binding and identify single amino acids within myosin VI required for binding to cargo adaptors. We not only show that the adaptor proteins can directly interact with the cargo-binding tail of myosin VI, but our in vitro studies also suggest that multiple adaptor proteins can bind simultaneously to non-overlapping sites in the myosin VI tail. In conclusion, our characterisation of the human myosin VI deafness mutant (R1166X) suggests that defects in cargo binding may leave myosin VI in a primed/activated state with an increased actin-binding ability.
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spelling pubmed-50743682016-10-21 Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding Arden, Susan D. Tumbarello, David A. Butt, Tariq Kendrick-Jones, John Buss, Folma Biochem J Research Articles Mutations in myosin VI have been associated with autosomal-recessive (DFNB37) and autosomal-dominant (DFNA22) deafness in humans. Here, we characterise an myosin VI nonsense mutation (R1166X) that was identified in a family with hereditary hearing loss in Pakistan. This mutation leads to the deletion of the C-terminal 120 amino acids of the myosin VI cargo-binding domain, which includes the WWY-binding motif for the adaptor proteins LMTK2, Tom1 as well as Dab2. Interestingly, compromising myosin VI vesicle-binding ability by expressing myosin VI with the R1166X mutation or with single point mutations in the adaptor-binding sites leads to increased F-actin binding of this myosin in vitro and in vivo. As our results highlight the importance of cargo attachment for regulating actin binding to the motor domain, we perform a detailed characterisation of adaptor protein binding and identify single amino acids within myosin VI required for binding to cargo adaptors. We not only show that the adaptor proteins can directly interact with the cargo-binding tail of myosin VI, but our in vitro studies also suggest that multiple adaptor proteins can bind simultaneously to non-overlapping sites in the myosin VI tail. In conclusion, our characterisation of the human myosin VI deafness mutant (R1166X) suggests that defects in cargo binding may leave myosin VI in a primed/activated state with an increased actin-binding ability. Portland Press Ltd. 2016-10-01 2016-09-27 /pmc/articles/PMC5074368/ /pubmed/27474411 http://dx.doi.org/10.1042/BCJ20160571 Text en © 2016 The Author(s) https://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 License 4.0 (CC BY) (https://creativecommons.org/licenses/by/4.0) .
spellingShingle Research Articles
Arden, Susan D.
Tumbarello, David A.
Butt, Tariq
Kendrick-Jones, John
Buss, Folma
Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding
title Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding
title_full Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding
title_fullStr Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding
title_full_unstemmed Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding
title_short Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding
title_sort loss of cargo binding in the human myosin vi deafness mutant (r1166x) leads to increased actin filament binding
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5074368/
https://www.ncbi.nlm.nih.gov/pubmed/27474411
http://dx.doi.org/10.1042/BCJ20160571
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