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Measuring Integrin Conformational Change on the Cell Surface with Super-Resolution Microscopy
We use super-resolution interferometric photoactivation and localization microscopy (iPALM) and a constrained photoactivatable fluorescent protein integrin fusion to measure the displacement of the head of integrin lymphocyte function-associated 1 (LFA-1) resulting from integrin conformational chang...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5851489/ https://www.ncbi.nlm.nih.gov/pubmed/29444440 http://dx.doi.org/10.1016/j.celrep.2018.01.062 |
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author | Moore, Travis I. Aaron, Jesse Chew, Teng-Leong Springer, Timothy A. |
author_facet | Moore, Travis I. Aaron, Jesse Chew, Teng-Leong Springer, Timothy A. |
author_sort | Moore, Travis I. |
collection | PubMed |
description | We use super-resolution interferometric photoactivation and localization microscopy (iPALM) and a constrained photoactivatable fluorescent protein integrin fusion to measure the displacement of the head of integrin lymphocyte function-associated 1 (LFA-1) resulting from integrin conformational change on the cell surface. We demonstrate that the distance of the LFA-1 head increases substantially between basal and ligand-engaged conformations, which can only be explained at the molecular level by integrin extension. We further demonstrate that one class of integrin antagonist maintains the bent conformation, while another antagonist class induces extension. Our molecular scale measurements on cell-surface LFA-1 are in excellent agreement with distances derived from crystallographic and electron microscopy structures of bent and extended integrins. Our distance measurements are also in excellent agreement with a previous model of LFA-1 bound to ICAM-1 derived from the orientation of LFA-1 on the cell surface measured using fluorescence polarization microscopy. |
format | Online Article Text |
id | pubmed-5851489 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
record_format | MEDLINE/PubMed |
spelling | pubmed-58514892018-03-14 Measuring Integrin Conformational Change on the Cell Surface with Super-Resolution Microscopy Moore, Travis I. Aaron, Jesse Chew, Teng-Leong Springer, Timothy A. Cell Rep Article We use super-resolution interferometric photoactivation and localization microscopy (iPALM) and a constrained photoactivatable fluorescent protein integrin fusion to measure the displacement of the head of integrin lymphocyte function-associated 1 (LFA-1) resulting from integrin conformational change on the cell surface. We demonstrate that the distance of the LFA-1 head increases substantially between basal and ligand-engaged conformations, which can only be explained at the molecular level by integrin extension. We further demonstrate that one class of integrin antagonist maintains the bent conformation, while another antagonist class induces extension. Our molecular scale measurements on cell-surface LFA-1 are in excellent agreement with distances derived from crystallographic and electron microscopy structures of bent and extended integrins. Our distance measurements are also in excellent agreement with a previous model of LFA-1 bound to ICAM-1 derived from the orientation of LFA-1 on the cell surface measured using fluorescence polarization microscopy. 2018-02-13 /pmc/articles/PMC5851489/ /pubmed/29444440 http://dx.doi.org/10.1016/j.celrep.2018.01.062 Text en This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
spellingShingle | Article Moore, Travis I. Aaron, Jesse Chew, Teng-Leong Springer, Timothy A. Measuring Integrin Conformational Change on the Cell Surface with Super-Resolution Microscopy |
title | Measuring Integrin Conformational Change on the Cell Surface with Super-Resolution Microscopy |
title_full | Measuring Integrin Conformational Change on the Cell Surface with Super-Resolution Microscopy |
title_fullStr | Measuring Integrin Conformational Change on the Cell Surface with Super-Resolution Microscopy |
title_full_unstemmed | Measuring Integrin Conformational Change on the Cell Surface with Super-Resolution Microscopy |
title_short | Measuring Integrin Conformational Change on the Cell Surface with Super-Resolution Microscopy |
title_sort | measuring integrin conformational change on the cell surface with super-resolution microscopy |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5851489/ https://www.ncbi.nlm.nih.gov/pubmed/29444440 http://dx.doi.org/10.1016/j.celrep.2018.01.062 |
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