Kinetics of the secretory response in bovine chromaffin cells following flash photolysis of caged Ca2+

Heinemann, Christian; Chow, Robert H.; Neher, Erwin; Zucker, Robert S.

doi:10.1016/s0006-3495(94)80744-1

Cited by 330 publications

(355 citation statements)

References 41 publications

Supporting

Mentioning

324

Contrasting

Unclassified

Order By: Relevance

“…Alternatively, the delay in human β-cell exocytosis could be due to an inherent delay in the exocytotic process, which would show up as a delayed increase in capacitance after flash-release of caged-Ca 2+ . Flash-release experiments have still not been performed in human β-cells, but we find it unlikely that they will reveal such long inherent delays, since exocytosis occurs < 15 ms after flash-release of caged-Ca 2+ in other endocrine cells (Barg et al, 2001;Thomas et al, 1993;Heinemann et al, 1994).…”

Section: Exocytosis In Human β-Cellsmentioning

confidence: 93%

Mathematical modeling and statistical analysis of calcium-regulated insulin granule exocytosis in β-cells from mice and humans

Pedersen

Cortese

Eliasson

2011

Progress in Biophysics and Molecular Biology

View full text Add to dashboard Cite

Section: Exocytosis In Human β-Cellsmentioning

confidence: 93%

Mathematical modeling and statistical analysis of calcium-regulated insulin granule exocytosis in β-cells from mice and humans

Pedersen

Cortese

Eliasson

2011

Progress in Biophysics and Molecular Biology

View full text Add to dashboard Cite

“…In turn, depolarization causes the activation of the L-type voltage-dependent calcium channels that result in the influx of extracellular calcium. This increased intracellular calcium then serves as a trigger for the initial fusion of insulincontaining dense core granules with the plasma membrane (8,9).…”

mentioning

confidence: 99%

Syntaxin 4 and Synip (Syntaxin 4 Interacting Protein) Regulate Insulin Secretion in the Pancreatic β HC-9 Cell

Saito

Okada

Yamada

et al. 2003

Journal of Biological Chemistry

View full text Add to dashboard Cite

Although syntaxin 1 is generally thought to function as the primary target-N-ethylmaleimide-sensitive factor attachment protein receptor required for pancreatic ␤ cell insulin secretion, we have observed that overexpression of a dominant-interfering syntaxin 4 mutant (syntaxin 4/⌬TM) attenuated glucose-stimulated insulin secretion in ␤HC-9 cells. Furthermore, these cells express the selective syntaxin 4-binding protein Synip (syntaxin 4 interacting protein), and Synip was specifically co-immunoprecipitated with syntaxin 4 but not syntaxin 1. Overexpression of the full-length Synip protein (Synip/wild type) inhibited VAMP2 association with syntaxin 4 and decreased glucose-stimulated insulin secretion. This did not occur with a Synip mutant (Synip/ ⌬EF) that was incapable of binding syntaxin 4. Consistent with a functional role of syntaxin 4 in this process, expression of syntaxin 4/⌬TM also inhibited glucosestimulated insulin secretion. Furthermore, analysis of first and second phase insulin secretion demonstrated that syntaxin 4/⌬TM mainly suppressed the second phase of insulin secretion. In contrast, overexpression of Synip resulted in an inhibition of both the first and second phase of glucose-stimulated insulin secretion. These data demonstrate that syntaxin 4 plays a functional role on insulin release and granule fusion in ␤ cells and that this process is regulated by the syntaxin 4-specific binding protein Synip.It is well established that glucose-stimulated insulin secretion occurs through a complex metabolic network in which the increased flux of glucose in pancreatic ␤ cells elevates the intracellular ATP/ADP ratio (1-5). The increased ATP/ADP ratio results in the closure of the ATP-sensitive potassium channel (K ATP channels) and subsequent cellular depolarization (6, 7). In turn, depolarization causes the activation of the L-type voltage-dependent calcium channels that result in the influx of extracellular calcium. This increased intracellular calcium then serves as a trigger for the initial fusion of insulincontaining dense core granules with the plasma membrane (8, 9).Although the calcium trigger mechanism, trafficking, and fusion of insulin granules have not been fully elucidated, recent studies have suggested that the majority of granules that initially fuse with the plasma membrane are localized beneath the plasma membrane in a bound (docked) state (10 -12). This pool of insulin granules has been referred as the readily releasable pool, and it appears to account for the first phase of stimulusmediated insulin secretion (13). This initial release process requires the functional interactions of the t-SNARE 1 proteins, syntaxin 1 and SNAP25, with the v-SNARE protein, VAMP2. For example, the use of SNARE mutants or various SNARE protein-specific proteolytic toxins prevent regulated insulin secretion (14 -17). However, since these endotoxins do not proteolyze complexed SNARE proteins, it is thought that the plasma membrane-bound (docked) insulin granules first undergo a priming step (core SNARE complex...

show abstract

“…With capacitance detection, postsynaptic sensitivity is not an issue, and Ca 2ϩ can be maintained at constant levels using photorelease of caged Ca 2ϩ . A decline in the rate of capacitance increase during sustained elevation of intracellular Ca 2ϩ has been interpreted as evidence for rapid depletion of release-ready vesicle pools (Neher and Zucker 1993;Thomas et al, 1993;Heidelberger et al, 1994;Heinemann et al, 1994).…”

mentioning

confidence: 99%

Short-Term Changes in the Ca²⁺-Exocytosis Relationship during Repetitive Pulse Protocols in Bovine Adrenal Chromaffin Cells

1997

View full text Add to dashboard Cite

Stimulus-secretion coupling was monitored with capacitance detection in bovine chromaffin cells recorded in perforated patch mode and stimulated with trains of depolarizing pulses. A subset of stimulus trains evoked a response with a Ca 2ϩ -exocytosis relationship identical to that obtained for single depolarizing pulses (Engisch and Nowycky, 1996). Other trains evoked responses with enhanced or diminished Ca 2ϩ efficacy relative to this input-output function. The probability of obtaining a particular Ca 2ϩ -exocytosis relationship was correlated with the amount of Ca 2ϩ entry per pulse, such that shorter pulses or smaller currents were associated with the greatest efficacy, and longer pulses and larger currents with the lowest efficacy.Apparent enhancements in Ca 2ϩ efficacy were not caused by residual Ca 2ϩ summing between pulses, because decreasing the interval between pulses usually reduced efficacy in the same cell; conversely, increasing the interval between pulses did not prevent an enhanced Ca 2ϩ -exocytosis relationship. Apparent decreases in Ca 2ϩ efficacy were not caused by depletion of an available pool of release-ready vesicles, because an equivalent amount of total Ca 2ϩ entry during a single long depolarizing pulse usually evoked a much larger secretory response in the same cell. Finally, there were no striking differences in global Ca 2ϩ levels monitored with the fluorescent indicator Fura Red that could account for apparent changes in Ca 2ϩ efficacy during repetitive stimulus protocols. It appears that in chromaffin cells, the Ca 2ϩ -exocytosis relationship is subject to activity-dependent changes during a stimulus train and can be modulated up or down from a basal state accessed by single pulse stimulations.

show abstract

Kinetics of the secretory response in bovine chromaffin cells following flash photolysis of caged Ca2+

Cited by 330 publications

References 41 publications

Mathematical modeling and statistical analysis of calcium-regulated insulin granule exocytosis in β-cells from mice and humans

Mathematical modeling and statistical analysis of calcium-regulated insulin granule exocytosis in β-cells from mice and humans

Syntaxin 4 and Synip (Syntaxin 4 Interacting Protein) Regulate Insulin Secretion in the Pancreatic β HC-9 Cell

Short-Term Changes in the Ca²⁺-Exocytosis Relationship during Repetitive Pulse Protocols in Bovine Adrenal Chromaffin Cells

Contact Info

Product

Resources

About

Kinetics of the secretory response in bovine chromaffin cells following flash photolysis of caged Ca2+

Cited by 330 publications

References 41 publications

Mathematical modeling and statistical analysis of calcium-regulated insulin granule exocytosis in β-cells from mice and humans

Mathematical modeling and statistical analysis of calcium-regulated insulin granule exocytosis in β-cells from mice and humans

Syntaxin 4 and Synip (Syntaxin 4 Interacting Protein) Regulate Insulin Secretion in the Pancreatic β HC-9 Cell

Short-Term Changes in the Ca2+-Exocytosis Relationship during Repetitive Pulse Protocols in Bovine Adrenal Chromaffin Cells

Contact Info

Product

Resources

About

Short-Term Changes in the Ca²⁺-Exocytosis Relationship during Repetitive Pulse Protocols in Bovine Adrenal Chromaffin Cells