| 1.Research Institution | Okazaki National Research Institutes | |
| 2.Research Area | Life Science | |
| 3.Research Field | Cellular Signaling | |
| 4.Term of Project | FY1996〜FY2000 | |
| 5.Project Number | 96L00301 | |
| 6.Title of Project | Calcium Signaling in Secretion |
| Name | Institution,Department | Title of Position |
| Kasai, Haruo | National Institute for Physiological Sciences | Professor |
8.Core Members
9.Cooperating Researchers
| Names | Institution,Department | Title of Position |
| Kukita, Fumio | National Institute for Physiological Sciences | Research Associate |
| Nemoto, Kazuki | National Institute for Physiological Sciences | Research Associate |
| Takahashi, Noriko | National Institute for Physiological Sciences | Research Associate |
10.Summary of Research Results
|
We have systematically investigated the Ca2+ dependent exocytosis from neuronal, endocrine and exocrine cells in a quantitative manner, using caged Ca2+ compounds, amperometry and 2-photon excitation imaging. 1. The results of neuronal PC12 cell line indicate that the rate of exocytosis are markedly different between the dense-core vesicles (LVs) and the small synaptic vesicles (SVs), even though they are stimulated by the same amplitudes of Ca2+ increases. Removal of neuronal SNAREs resulted in further slowing of SVs in PC12 cells, while the amplitude of exocytosis remained unchanged, suggesting that the neuronal SNAREs controls the rate of exocytosis. Natures of Ca2+ sensors were investigated by using different divalent cations. The results is consistent with the role of synaptotamin in the LV exocytosis, while Ca2+ sensors for SVs likely involve another Ca2+ sensing mechanisms. 2. Exocytosis of insulin vesicles were investigated with amperometry and with 2-photon excitation imaging. Our results indicate the presence of two distinct populations of insulin vesicles, one undergoes exocytosis rapidly upon stimulation by Ca2+ and cAMP, while the other slowly by Ca2+. The two populations of vesicles can account for the classical two phases of insulin exocytoses from the islet of Langerhans under high-glucose stimulation. 3. Exocytosis of exocrine glands is found to require micromolar increases in Ca2+, as in the case of neuronal and endocrine cells, suggesting the involvement of synaptotagmin in the exocrine secretion. We found sequential progresses of exocytosis into the cytosol of acinar cells with physiological agonist stimulation. These results indicate that the plasma membrane factor is necessary for the fusion of LVs, and that the Ca2+ release from internal Ca2+ stores is optimized to maintain such sequential exocytosis. |
11.Key Words
(1)Secretion、(2)Calcium、(3)Synapse
(4)Exocrine gland、(5)Pancreatic Beta-cells、(6)Insulin
12.References
| Author | Title of Article | |||
| Kasai, H | Two components of exocytosis and endocytosis in phaeochromocytoma cells studied using caged-Ca2+ compounds | |||
| Journal | Volume | Year | Pages Concerned | |
| Journal of Physiology | 496 | 1996 | 53-65 | |
| Author | Title of Article | |||
| Ninomiya, Y. | Ca2+-dependent exocytotic pathways in Chinese hamster ovary fibroblast revealed by capacitace measurement and caged-Ca2+ compound | |||
| Journal | Volume | Year | Pages Concerned | |
| Journal of Biological Chemistry | 271 | 1996 | 17751-17754 | |
| Author | Title of Article | |||
| Kasai, H. | Neuronal Ca2+ signalling | |||
| Journal | Volume | Year | Pages Concerned | |
| Seminar in Neuroscience | 8 | 1996 | 259 | |
| Author | Title of Article | |||
| Petersen, O. H. P. | Intracellular calcium. in Text book of Receptor Pharmacology, ed. J. C. Foreman and T. Johansen | |||
| Journal | Volume | Year | Pages Concerned | |
| CRC Press, England | 1996 | 213-226 | ||
| Author | Title of Article | |||
| Sjoedin, L. | Cytoplasmic Ca2+ gradients evoked by acetylcholine and peptides in pancreatic acinar cells of the guinea pig | |||
| Journal | Volume | Year | Pages Concerned | |
| Pflugers Archiv | 433 | 1997 | 397-402 | |
| Author | Title of Article | |||
| Ito, K. | Micromolar and submicromolar Ca2+ spikes regulating distinct cellular functions in pancreatic acinar cells | |||
| Journal | Volume | Year | Pages Concerned | |
| EMBO Journal | 16 | 1997 | 242-251 | |
| Author | Title of Article | |||
| Ninomiya, Y. | Kinetic diversity in the fusion of exocytotic vesicles | |||
| Journal | Volume | Year | Pages Concerned | |
| EMBO Journal | 16 | 1997 | 929-934 | |
| Author | Title of Article | |||
| Takahashi, N. | Multiple exocytotic pathways in pancreatic β-cells | |||
| Journal | Volume | Year | Pages Concerned | |
| Journal of Cell Biology | 138 | 1997 | 55-64 | |
| Author | Title of Article | |||
| Kasai, H. | Ca2+ dependent exocytosis in endocrine, exocrine and non-secretory cells | |||
| Journal | Volume | Year | Pages Concerned | |
| Korean Journal of Physiology and Pharmacology | 2 | 1998 | 1-7 | |
| Author | Title of Article | |||
| Kasai, H. | Comparative biology of Ca2+-dependent exocytosis: implications of kinetic diversity for secretory function | |||
| Journal | Volume | Year | Pages Concerned | |
| Trends in Neurosciences | 22 | 1999 | 88-93 | |
| Author | Title of Article | |||
| Takahashi, N. | Post-priming actions of ATP on Ca2+-dependent exocytosis in pancreatic beta cells | |||
| Journal | Volume | Year | Pages Concerned | |
| Proceedings of the National Academy of Sciences of the U. S. A. | 96 | 1999 | 760-765 | |
| Author | Title of Article | |||
| Kasai, H. | Multiple components of exocytosis and Ca2+ requirements. | |||
| Journal | Volume | Year | Pages Concerned | |
| Philosophical Transactions of the Royal Society of London- Series B:Biological Sciences | 354 | 1999 | 331-335 | |
| Author | Title of Article | |||
| Kasai, H. | Mutiple and diverse forms of regulated exocytosis revealed in wild-type and defective PC12 cells | |||
| Journal | Volume | Year | Pages Concerned | |
| Proceedings of the National Academy of Sciences of the U. S. A. | 96 | 1999 | 945-949 | |
| Author | Title of Article | |||
| Eto, K. | Role of NADH shuttle system in glucose-induced activation of mitochondrial metabolism and insulin secretion | |||
| Journal | Volume | Year | Pages Concerned | |
| Science | 283 | 1999 | 981-985 | |
| Author | Title of Article | |||
| Ito, K. | Kinetic control of multiple forms of Ca2+ spikes by inositol trisphosphate in pancreatic acinar cells | |||
| Journal | Volume | Year | Pages Concerned | |
| Journal of Cell Bioogy | 146 | 1999 | 405-414 | |
| Author | Title of Article | |||
| Eto, K. | NADH shuttle system regulates KATP channel-dependent pathway and steps distal to cytosolic Ca2+ concentration elevation in glucose-induced insulin secretion | |||
| Journal | Volume | Year | Pages Concerned | |
| Journal of Biological Chemistry | 274(36) | 1999 | 25386-25393 | |
| Author | Title of Article | |||
| Maeda, H. | Supralinear Ca2+ signaling by cooperative and mobile Ca2+ buffering in Purkinje neurons | |||
| Journal | Volume | Year | Pages Concerned | |
| Neuron | 24 | 1999 | 989-1002 | |
| Author | Title of Article | |||
| Tsubamoto Y. | Hexamminecobalt (III) Chloride Inhibits Glucose-Induced Insulin Secretion at the Exocytotic Process | |||
| Journal | Volume | Year | Pages Concerned | |
| Journal of Biological Chemistry | 276, | 2001 | 2979-2985 | |
| Author | Title of Article | |||
| Nemoto, T. | Sequential-replenishment mechanism of exocytosis in pancreatic acini. | |||
| Journal | Volume | Year | Pages Concerned | |
| Nature Cell Biology | 3 | 2001 | 253-258 | |
| Author | Title of Article | |||
| Kishimoto, T. | Ion selectivities of the Ca2+ sensors for exocytosis in rat phaeochromocytoma cells | |||
| Journal | Volume | Year | Pages Concerned | |
| Journal of Physiology(Lonon) | in press | 2001 | ||