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001-es BibID:	BIBFORM096379
035-os BibID:	(Scopus)85100993394
Első szerző:	Sanchez, Colline
Cím:	Detection of Ca2+ transients near ryanodine receptors by targeting fluorescent Ca2+ sensors to the triad / Colline Sanchez, Christine Berthier, Yves Tourneur, Laloé Monteiro, Bruno Allard, Laszlo Csernoch, Vincent Jacquemond
Dátum:	2021
ISSN:	0022-1295 1540-7748
Megjegyzések:	In intact muscle fibers, functional properties of ryanodine receptor (RYR)?mediated sarcoplasmic reticulum (SR) Ca2+ release triggered by activation of the voltage sensor CaV1.1 have so far essentially been addressed with diffusible Ca2+-sensitive dyes. Here, we used a domain (T306) of the protein triadin to target the Ca2+-sensitive probe GCaMP6f to the junctional SR membrane, in the immediate vicinity of RYR channels, within the triad region. Fluorescence of untargeted GCaMP6f was distributed throughout the muscle fibers and experienced large Ca2+-dependent changes, with obvious kinetic delays, upon application of voltage-clamp depolarizing pulses. Conversely, T306-GCaMP6f localized to the triad and generated Ca2+-dependent fluorescence transients of lower amplitude and faster kinetics for low and intermediate levels of Ca2+ release than those of untargeted GCaMP6f. By contrast, model simulation of the spatial gradients of Ca2+ following Ca2+ release predicted limited kinetic differences under the assumptions that the two probes were present at the same concentration and suffered from identical kinetic limitations. At the spatial level, T306-GCaMP6f transients within distinct regions of a same fiber yielded a uniform time course, even at low levels of Ca2+ release activation. Similar observations were made using GCaMP6f fused to the ?1 auxiliary subunit of CaV1.1. Despite the probe's limitations, our results point out the remarkable synchronicity of voltage-dependent Ca2+ release activation and termination among individual triads and highlight the potential of the approach to visualize activation or closure of single groups of RYR channels. We anticipate targeting of improved Ca2+ sensors to the triad will provide illuminating insights into physiological normal RYR function and its dysfunction under stress or pathological conditions.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk SKELETAL-MUSCLE FIBERS CALCIUM-RELEASE SARCOPLASMIC-RETICULUM MEMBRANE DEPOLARIZATION VOLTAGE-DEPENDENCE MYOPLASMIC CALCIUM ELEMENTARY EVENTS MOUSE CALSEQUESTRIN EXPRESSION
Megjelenés:	Journal of General Physiology. - 153 : 4 (2021), p. e202012592. -
További szerzők:	Berthier, Christine Tourneur, Yves Monteiro, Laloé Allard, Bruno Csernoch László (1961-) (élettanász) Jacquemond, Vincent
Pályázati támogatás:	GINOP-2.3.2-15-2016-00044 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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