α-Synuclein overexpression in PC12 and chromaffin cells impairs catecholamine release by interfering with a late step in exocytosis

Kristin E. Larsen, Yvonne Schmitz, Matthew D. Troyer, Eugene Mosharov, Paula Dietrich, Abrar Z. Quazi, Magali Savalle, Venu Nemani, Farrukh A. Chaudhry, Robert H. Edwards, Leonidas Stefanis, David Sulzer

Research output: Contribution to journalArticle

255 Citations (Scopus)

Abstract

α-Synuclein (α-syn), a protein implicated in Parkinson's disease pathogenesis, is a presynaptic protein suggested to regulate transmitter release. We explored how α-syn overexpression in PC12 and chromaffin cells, which exhibit low endogenous α-syn levels relative to neurons, affects catecholamine release. Overexpression of wild-type or A30P mutant α-syn in PC12 cell lines inhibited evoked catecholamine release without altering calcium threshold or cooperativity of release. Electron micrographs revealed that vesicular pools were not reduced but that, on the contrary, a marked accumulation of morphologically "docked" vesicles was apparent in the α-syn-overexpressing lines. We used amperometric recordings from chromaffin cells derived from mice that overexpress A30P or wild-type (WT) α-syn, as well as chromaffin cells from control and α-syn null mice, to determine whether the filling of vesicles with the transmitter was altered. The quantal size and shape characteristics of amperometric events were identical for all mouse lines, suggesting that overexpression of WT or mutant α-syn did not affect vesicular transmitter accumulation or the kinetics of vesicle fusion. The frequency and number of exocytotic events per stimulus, however, was lower for both WT and A30P α-syn-overexpressing cells. The α-synoverexpressing cells exhibited reduced depression of evoked release in response to repeated stimuli, consistent with a smaller population of readily releasable vesicles. We conclude that α-syn overexpression inhibits a vesicle "priming" step, after secretory vesicle trafficking to "docking" sites but before calcium-dependent vesicle membrane fusion.

Original languageEnglish (US)
Pages (from-to)11915-11922
Number of pages8
JournalJournal of Neuroscience
Volume26
Issue number46
DOIs
StatePublished - Nov 15 2006

Fingerprint

Synucleins
Chromaffin Cells
PC12 Cells
Exocytosis
Catecholamines
Calcium
Membrane Fusion
Secretory Vesicles
Parkinson Disease
Proteins
Electrons
Neurons
Cell Line
Population

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)

Cite this

α-Synuclein overexpression in PC12 and chromaffin cells impairs catecholamine release by interfering with a late step in exocytosis. / Larsen, Kristin E.; Schmitz, Yvonne; Troyer, Matthew D.; Mosharov, Eugene; Dietrich, Paula; Quazi, Abrar Z.; Savalle, Magali; Nemani, Venu; Chaudhry, Farrukh A.; Edwards, Robert H.; Stefanis, Leonidas; Sulzer, David.

In: Journal of Neuroscience, Vol. 26, No. 46, 15.11.2006, p. 11915-11922.

Research output: Contribution to journalArticle

Larsen, KE, Schmitz, Y, Troyer, MD, Mosharov, E, Dietrich, P, Quazi, AZ, Savalle, M, Nemani, V, Chaudhry, FA, Edwards, RH, Stefanis, L & Sulzer, D 2006, 'α-Synuclein overexpression in PC12 and chromaffin cells impairs catecholamine release by interfering with a late step in exocytosis', Journal of Neuroscience, vol. 26, no. 46, pp. 11915-11922. https://doi.org/10.1523/JNEUROSCI.3821-06.2006
Larsen, Kristin E. ; Schmitz, Yvonne ; Troyer, Matthew D. ; Mosharov, Eugene ; Dietrich, Paula ; Quazi, Abrar Z. ; Savalle, Magali ; Nemani, Venu ; Chaudhry, Farrukh A. ; Edwards, Robert H. ; Stefanis, Leonidas ; Sulzer, David. / α-Synuclein overexpression in PC12 and chromaffin cells impairs catecholamine release by interfering with a late step in exocytosis. In: Journal of Neuroscience. 2006 ; Vol. 26, No. 46. pp. 11915-11922.
@article{3f853bf99230423fbbad9737ea60fccf,
title = "α-Synuclein overexpression in PC12 and chromaffin cells impairs catecholamine release by interfering with a late step in exocytosis",
abstract = "α-Synuclein (α-syn), a protein implicated in Parkinson's disease pathogenesis, is a presynaptic protein suggested to regulate transmitter release. We explored how α-syn overexpression in PC12 and chromaffin cells, which exhibit low endogenous α-syn levels relative to neurons, affects catecholamine release. Overexpression of wild-type or A30P mutant α-syn in PC12 cell lines inhibited evoked catecholamine release without altering calcium threshold or cooperativity of release. Electron micrographs revealed that vesicular pools were not reduced but that, on the contrary, a marked accumulation of morphologically {"}docked{"} vesicles was apparent in the α-syn-overexpressing lines. We used amperometric recordings from chromaffin cells derived from mice that overexpress A30P or wild-type (WT) α-syn, as well as chromaffin cells from control and α-syn null mice, to determine whether the filling of vesicles with the transmitter was altered. The quantal size and shape characteristics of amperometric events were identical for all mouse lines, suggesting that overexpression of WT or mutant α-syn did not affect vesicular transmitter accumulation or the kinetics of vesicle fusion. The frequency and number of exocytotic events per stimulus, however, was lower for both WT and A30P α-syn-overexpressing cells. The α-synoverexpressing cells exhibited reduced depression of evoked release in response to repeated stimuli, consistent with a smaller population of readily releasable vesicles. We conclude that α-syn overexpression inhibits a vesicle {"}priming{"} step, after secretory vesicle trafficking to {"}docking{"} sites but before calcium-dependent vesicle membrane fusion.",
author = "Larsen, {Kristin E.} and Yvonne Schmitz and Troyer, {Matthew D.} and Eugene Mosharov and Paula Dietrich and Quazi, {Abrar Z.} and Magali Savalle and Venu Nemani and Chaudhry, {Farrukh A.} and Edwards, {Robert H.} and Leonidas Stefanis and David Sulzer",
year = "2006",
month = "11",
day = "15",
doi = "10.1523/JNEUROSCI.3821-06.2006",
language = "English (US)",
volume = "26",
pages = "11915--11922",
journal = "Journal of Neuroscience",
issn = "0270-6474",
publisher = "Society for Neuroscience",
number = "46",

}

TY - JOUR

T1 - α-Synuclein overexpression in PC12 and chromaffin cells impairs catecholamine release by interfering with a late step in exocytosis

AU - Larsen, Kristin E.

AU - Schmitz, Yvonne

AU - Troyer, Matthew D.

AU - Mosharov, Eugene

AU - Dietrich, Paula

AU - Quazi, Abrar Z.

AU - Savalle, Magali

AU - Nemani, Venu

AU - Chaudhry, Farrukh A.

AU - Edwards, Robert H.

AU - Stefanis, Leonidas

AU - Sulzer, David

PY - 2006/11/15

Y1 - 2006/11/15

N2 - α-Synuclein (α-syn), a protein implicated in Parkinson's disease pathogenesis, is a presynaptic protein suggested to regulate transmitter release. We explored how α-syn overexpression in PC12 and chromaffin cells, which exhibit low endogenous α-syn levels relative to neurons, affects catecholamine release. Overexpression of wild-type or A30P mutant α-syn in PC12 cell lines inhibited evoked catecholamine release without altering calcium threshold or cooperativity of release. Electron micrographs revealed that vesicular pools were not reduced but that, on the contrary, a marked accumulation of morphologically "docked" vesicles was apparent in the α-syn-overexpressing lines. We used amperometric recordings from chromaffin cells derived from mice that overexpress A30P or wild-type (WT) α-syn, as well as chromaffin cells from control and α-syn null mice, to determine whether the filling of vesicles with the transmitter was altered. The quantal size and shape characteristics of amperometric events were identical for all mouse lines, suggesting that overexpression of WT or mutant α-syn did not affect vesicular transmitter accumulation or the kinetics of vesicle fusion. The frequency and number of exocytotic events per stimulus, however, was lower for both WT and A30P α-syn-overexpressing cells. The α-synoverexpressing cells exhibited reduced depression of evoked release in response to repeated stimuli, consistent with a smaller population of readily releasable vesicles. We conclude that α-syn overexpression inhibits a vesicle "priming" step, after secretory vesicle trafficking to "docking" sites but before calcium-dependent vesicle membrane fusion.

AB - α-Synuclein (α-syn), a protein implicated in Parkinson's disease pathogenesis, is a presynaptic protein suggested to regulate transmitter release. We explored how α-syn overexpression in PC12 and chromaffin cells, which exhibit low endogenous α-syn levels relative to neurons, affects catecholamine release. Overexpression of wild-type or A30P mutant α-syn in PC12 cell lines inhibited evoked catecholamine release without altering calcium threshold or cooperativity of release. Electron micrographs revealed that vesicular pools were not reduced but that, on the contrary, a marked accumulation of morphologically "docked" vesicles was apparent in the α-syn-overexpressing lines. We used amperometric recordings from chromaffin cells derived from mice that overexpress A30P or wild-type (WT) α-syn, as well as chromaffin cells from control and α-syn null mice, to determine whether the filling of vesicles with the transmitter was altered. The quantal size and shape characteristics of amperometric events were identical for all mouse lines, suggesting that overexpression of WT or mutant α-syn did not affect vesicular transmitter accumulation or the kinetics of vesicle fusion. The frequency and number of exocytotic events per stimulus, however, was lower for both WT and A30P α-syn-overexpressing cells. The α-synoverexpressing cells exhibited reduced depression of evoked release in response to repeated stimuli, consistent with a smaller population of readily releasable vesicles. We conclude that α-syn overexpression inhibits a vesicle "priming" step, after secretory vesicle trafficking to "docking" sites but before calcium-dependent vesicle membrane fusion.

UR - http://www.scopus.com/inward/record.url?scp=33751113009&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33751113009&partnerID=8YFLogxK

U2 - 10.1523/JNEUROSCI.3821-06.2006

DO - 10.1523/JNEUROSCI.3821-06.2006

M3 - Article

C2 - 17108165

AN - SCOPUS:33751113009

VL - 26

SP - 11915

EP - 11922

JO - Journal of Neuroscience

JF - Journal of Neuroscience

SN - 0270-6474

IS - 46

ER -