Optical profiling of autonomous Ca2+ nanodomains generated by lysosomal TPC2 and TRPML1
<p>Multiple families of Ca<sup>2+</sup>-permeable channels co-exist on lysosomal Ca<sup>2+</sup> stores but how each family couples to its own unique downstream physiology is unclear. We have therefore investigated the Ca<sup>2+</sup>-signalling arc...
Main Authors: | , , |
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Format: | Journal article |
Language: | English |
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Elsevier
2023
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_version_ | 1797111289764380672 |
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author | Davis, LC Morgan, AJ Galione, A |
author_facet | Davis, LC Morgan, AJ Galione, A |
author_sort | Davis, LC |
collection | OXFORD |
description | <p>Multiple families of Ca<sup>2+</sup>-permeable channels co-exist on lysosomal Ca<sup>2+</sup> stores but how each family couples to its own unique downstream physiology is unclear. We have therefore investigated the Ca<sup>2+</sup>-signalling architecture underpinning different channels on the same vesicle that drive separate pathways, using phagocytosis as a physiological stimulus. Lysosomal Ca<sup>2+</sup>-channels are a major Ca<sup>2+</sup> source driving particle uptake in macrophages, but different channels drive different aspects of Fc-receptor-mediated phagocytosis: TPC2 couples to dynamin activation, whilst TRPML1 couples to lysosomal exocytosis. We hypothesised that they are driven by discrete local plumes of Ca<sup>2+</sup> around open channels (Ca<sup>2+</sup> nanodomains). To test this, we optimized Ca<sup>2+</sup>-nanodomain recordings by screening panels of genetically encoded Ca<sup>2+</sup> indicators (GECIs) fused to TPC2 to monitor the [Ca<sup>2+</sup>] next to the channel. Signal calibration accounting for the distance of the GECI from the channel mouth reveals that, during phagocytosis, TPC2 generates local Ca<sup>2+</sup> nanodomains around itself of up to 42 µM, nearly a hundred-fold greater than the global cytosolic [Ca<sup>2+</sup>] rise. We further show that TPC2 and TRPML1, though on the same lysosomes, generate autonomous Ca<sup>2+</sup> nanodomains of high [Ca<sup>2+</sup>] that are largely insulated from one another, a platform allowing their discrete Ca<sup>2+</sup>-decoding to promote unique respective physiologies.</p> |
first_indexed | 2024-03-07T08:06:42Z |
format | Journal article |
id | oxford-uuid:7e41a1b0-565a-4739-bef4-800dcd413e87 |
institution | University of Oxford |
language | English |
last_indexed | 2024-03-07T08:06:42Z |
publishDate | 2023 |
publisher | Elsevier |
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spelling | oxford-uuid:7e41a1b0-565a-4739-bef4-800dcd413e872023-11-07T10:01:08ZOptical profiling of autonomous Ca2+ nanodomains generated by lysosomal TPC2 and TRPML1Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:7e41a1b0-565a-4739-bef4-800dcd413e87EnglishSymplectic ElementsElsevier2023Davis, LCMorgan, AJGalione, A<p>Multiple families of Ca<sup>2+</sup>-permeable channels co-exist on lysosomal Ca<sup>2+</sup> stores but how each family couples to its own unique downstream physiology is unclear. We have therefore investigated the Ca<sup>2+</sup>-signalling architecture underpinning different channels on the same vesicle that drive separate pathways, using phagocytosis as a physiological stimulus. Lysosomal Ca<sup>2+</sup>-channels are a major Ca<sup>2+</sup> source driving particle uptake in macrophages, but different channels drive different aspects of Fc-receptor-mediated phagocytosis: TPC2 couples to dynamin activation, whilst TRPML1 couples to lysosomal exocytosis. We hypothesised that they are driven by discrete local plumes of Ca<sup>2+</sup> around open channels (Ca<sup>2+</sup> nanodomains). To test this, we optimized Ca<sup>2+</sup>-nanodomain recordings by screening panels of genetically encoded Ca<sup>2+</sup> indicators (GECIs) fused to TPC2 to monitor the [Ca<sup>2+</sup>] next to the channel. Signal calibration accounting for the distance of the GECI from the channel mouth reveals that, during phagocytosis, TPC2 generates local Ca<sup>2+</sup> nanodomains around itself of up to 42 µM, nearly a hundred-fold greater than the global cytosolic [Ca<sup>2+</sup>] rise. We further show that TPC2 and TRPML1, though on the same lysosomes, generate autonomous Ca<sup>2+</sup> nanodomains of high [Ca<sup>2+</sup>] that are largely insulated from one another, a platform allowing their discrete Ca<sup>2+</sup>-decoding to promote unique respective physiologies.</p> |
spellingShingle | Davis, LC Morgan, AJ Galione, A Optical profiling of autonomous Ca2+ nanodomains generated by lysosomal TPC2 and TRPML1 |
title | Optical profiling of autonomous Ca2+ nanodomains generated by lysosomal TPC2 and TRPML1 |
title_full | Optical profiling of autonomous Ca2+ nanodomains generated by lysosomal TPC2 and TRPML1 |
title_fullStr | Optical profiling of autonomous Ca2+ nanodomains generated by lysosomal TPC2 and TRPML1 |
title_full_unstemmed | Optical profiling of autonomous Ca2+ nanodomains generated by lysosomal TPC2 and TRPML1 |
title_short | Optical profiling of autonomous Ca2+ nanodomains generated by lysosomal TPC2 and TRPML1 |
title_sort | optical profiling of autonomous ca2 nanodomains generated by lysosomal tpc2 and trpml1 |
work_keys_str_mv | AT davislc opticalprofilingofautonomousca2nanodomainsgeneratedbylysosomaltpc2andtrpml1 AT morganaj opticalprofilingofautonomousca2nanodomainsgeneratedbylysosomaltpc2andtrpml1 AT galionea opticalprofilingofautonomousca2nanodomainsgeneratedbylysosomaltpc2andtrpml1 |