Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway.
Gain-of-function mutations in the human CaV2.1 gene CACNA1A cause familial hemiplegic migraine type 1 (FHM1). To characterize cellular problems potentially triggered by CaV2.1 gains of function, we engineered mutations encoding FHM1 amino-acid substitutions S218L (SL) and R192Q (RQ) into transgenes...
Main Authors: | , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Public Library of Science (PLoS)
2018-08-01
|
Series: | PLoS Genetics |
Online Access: | http://europepmc.org/articles/PMC6095605?pdf=render |
id |
doaj-8e84afdcc7674cc9a7d61507fc3ce816 |
---|---|
record_format |
Article |
spelling |
doaj-8e84afdcc7674cc9a7d61507fc3ce8162020-11-24T21:19:12ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042018-08-01148e100757710.1371/journal.pgen.1007577Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway.Douglas J BrusichAshlyn M SpringThomas D JamesCatherine J YeatesTimothy H HelmsC Andrew FrankGain-of-function mutations in the human CaV2.1 gene CACNA1A cause familial hemiplegic migraine type 1 (FHM1). To characterize cellular problems potentially triggered by CaV2.1 gains of function, we engineered mutations encoding FHM1 amino-acid substitutions S218L (SL) and R192Q (RQ) into transgenes of Drosophila melanogaster CaV2/cacophony. We expressed the transgenes pan-neuronally. Phenotypes were mild for RQ-expressing animals. By contrast, single mutant SL- and complex allele RQ,SL-expressing animals showed overt phenotypes, including sharply decreased viability. By electrophysiology, SL- and RQ,SL-expressing neuromuscular junctions (NMJs) exhibited enhanced evoked discharges, supernumerary discharges, and an increase in the amplitudes and frequencies of spontaneous events. Some spontaneous events were gigantic (10-40 mV), multi-quantal events. Gigantic spontaneous events were eliminated by application of TTX-or by lowered or chelated Ca2+-suggesting that gigantic events were elicited by spontaneous nerve firing. A follow-up genetic approach revealed that some neuronal hyperexcitability phenotypes were reversed after knockdown or mutation of Drosophila homologs of phospholipase Cβ (PLCβ), IP3 receptor, or ryanodine receptor (RyR)-all factors known to mediate Ca2+ release from intracellular stores. Pharmacological inhibitors of intracellular Ca2+ store release produced similar effects. Interestingly, however, the decreased viability phenotype was not reversed by genetic impairment of intracellular Ca2+ release factors. On a cellular level, our data suggest inhibition of signaling that triggers intracellular Ca2+ release could counteract hyperexcitability induced by gains of CaV2.1 function.http://europepmc.org/articles/PMC6095605?pdf=render |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Douglas J Brusich Ashlyn M Spring Thomas D James Catherine J Yeates Timothy H Helms C Andrew Frank |
spellingShingle |
Douglas J Brusich Ashlyn M Spring Thomas D James Catherine J Yeates Timothy H Helms C Andrew Frank Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway. PLoS Genetics |
author_facet |
Douglas J Brusich Ashlyn M Spring Thomas D James Catherine J Yeates Timothy H Helms C Andrew Frank |
author_sort |
Douglas J Brusich |
title |
Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway. |
title_short |
Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway. |
title_full |
Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway. |
title_fullStr |
Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway. |
title_full_unstemmed |
Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway. |
title_sort |
drosophila cav2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a ca2+ store release pathway. |
publisher |
Public Library of Science (PLoS) |
series |
PLoS Genetics |
issn |
1553-7390 1553-7404 |
publishDate |
2018-08-01 |
description |
Gain-of-function mutations in the human CaV2.1 gene CACNA1A cause familial hemiplegic migraine type 1 (FHM1). To characterize cellular problems potentially triggered by CaV2.1 gains of function, we engineered mutations encoding FHM1 amino-acid substitutions S218L (SL) and R192Q (RQ) into transgenes of Drosophila melanogaster CaV2/cacophony. We expressed the transgenes pan-neuronally. Phenotypes were mild for RQ-expressing animals. By contrast, single mutant SL- and complex allele RQ,SL-expressing animals showed overt phenotypes, including sharply decreased viability. By electrophysiology, SL- and RQ,SL-expressing neuromuscular junctions (NMJs) exhibited enhanced evoked discharges, supernumerary discharges, and an increase in the amplitudes and frequencies of spontaneous events. Some spontaneous events were gigantic (10-40 mV), multi-quantal events. Gigantic spontaneous events were eliminated by application of TTX-or by lowered or chelated Ca2+-suggesting that gigantic events were elicited by spontaneous nerve firing. A follow-up genetic approach revealed that some neuronal hyperexcitability phenotypes were reversed after knockdown or mutation of Drosophila homologs of phospholipase Cβ (PLCβ), IP3 receptor, or ryanodine receptor (RyR)-all factors known to mediate Ca2+ release from intracellular stores. Pharmacological inhibitors of intracellular Ca2+ store release produced similar effects. Interestingly, however, the decreased viability phenotype was not reversed by genetic impairment of intracellular Ca2+ release factors. On a cellular level, our data suggest inhibition of signaling that triggers intracellular Ca2+ release could counteract hyperexcitability induced by gains of CaV2.1 function. |
url |
http://europepmc.org/articles/PMC6095605?pdf=render |
work_keys_str_mv |
AT douglasjbrusich drosophilacav2channelsharboringhumanmigrainemutationscausesynapsehyperexcitabilitythatcanbesuppressedbyinhibitionofaca2storereleasepathway AT ashlynmspring drosophilacav2channelsharboringhumanmigrainemutationscausesynapsehyperexcitabilitythatcanbesuppressedbyinhibitionofaca2storereleasepathway AT thomasdjames drosophilacav2channelsharboringhumanmigrainemutationscausesynapsehyperexcitabilitythatcanbesuppressedbyinhibitionofaca2storereleasepathway AT catherinejyeates drosophilacav2channelsharboringhumanmigrainemutationscausesynapsehyperexcitabilitythatcanbesuppressedbyinhibitionofaca2storereleasepathway AT timothyhhelms drosophilacav2channelsharboringhumanmigrainemutationscausesynapsehyperexcitabilitythatcanbesuppressedbyinhibitionofaca2storereleasepathway AT candrewfrank drosophilacav2channelsharboringhumanmigrainemutationscausesynapsehyperexcitabilitythatcanbesuppressedbyinhibitionofaca2storereleasepathway |
_version_ |
1726006475543805952 |