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Function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βI domain α1-α1′ helix

We showed that the αLβ2 integrin with the non-functional mutation G150D cannot be induced with Mg/EGTA to express the mAb KIM127 epitope, which reports the leg-extended conformation. We extended the study to the αIIbβ3, an integrin without an αI domain. The equivalent mutation, i.e. G161D, also resu...

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Autores principales: Guan, Siyu, Tan, Suet-Mien, Li, Yan, Torres, Jaume, Alex Law, S.K.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613341/
https://www.ncbi.nlm.nih.gov/pubmed/28955909
http://dx.doi.org/10.1016/j.bbrep.2016.06.013
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author Guan, Siyu
Tan, Suet-Mien
Li, Yan
Torres, Jaume
Alex Law, S.K.
author_facet Guan, Siyu
Tan, Suet-Mien
Li, Yan
Torres, Jaume
Alex Law, S.K.
author_sort Guan, Siyu
collection PubMed
description We showed that the αLβ2 integrin with the non-functional mutation G150D cannot be induced with Mg/EGTA to express the mAb KIM127 epitope, which reports the leg-extended conformation. We extended the study to the αIIbβ3, an integrin without an αI domain. The equivalent mutation, i.e. G161D, also resulted in an expressible, but non-adhesive αIIbβ3 integrin. An NMR study of synthetic peptides spanning the α1-α1′ helix of the β3 I domain shows that both wild-type and mutant peptides are α-helical. However, whereas in the wild-type peptide this helix is continuous, the mutant presents a discontinuity, or kink, precisely at the site of mutation G161D. Our results suggest that the mutation may lock integrin heterodimers in a bent conformation that prevents integrin activation via conformational extension.
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spelling pubmed-56133412017-09-27 Function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βI domain α1-α1′ helix Guan, Siyu Tan, Suet-Mien Li, Yan Torres, Jaume Alex Law, S.K. Biochem Biophys Rep Research Article We showed that the αLβ2 integrin with the non-functional mutation G150D cannot be induced with Mg/EGTA to express the mAb KIM127 epitope, which reports the leg-extended conformation. We extended the study to the αIIbβ3, an integrin without an αI domain. The equivalent mutation, i.e. G161D, also resulted in an expressible, but non-adhesive αIIbβ3 integrin. An NMR study of synthetic peptides spanning the α1-α1′ helix of the β3 I domain shows that both wild-type and mutant peptides are α-helical. However, whereas in the wild-type peptide this helix is continuous, the mutant presents a discontinuity, or kink, precisely at the site of mutation G161D. Our results suggest that the mutation may lock integrin heterodimers in a bent conformation that prevents integrin activation via conformational extension. Elsevier 2016-06-20 /pmc/articles/PMC5613341/ /pubmed/28955909 http://dx.doi.org/10.1016/j.bbrep.2016.06.013 Text en © 2016 The Authors http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Research Article
Guan, Siyu
Tan, Suet-Mien
Li, Yan
Torres, Jaume
Alex Law, S.K.
Function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βI domain α1-α1′ helix
title Function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βI domain α1-α1′ helix
title_full Function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βI domain α1-α1′ helix
title_fullStr Function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βI domain α1-α1′ helix
title_full_unstemmed Function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βI domain α1-α1′ helix
title_short Function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βI domain α1-α1′ helix
title_sort function and conformation analyses of an aspartate substitution of the invariant glycine in the integrin βi domain α1-α1′ helix
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613341/
https://www.ncbi.nlm.nih.gov/pubmed/28955909
http://dx.doi.org/10.1016/j.bbrep.2016.06.013
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