Temperature-Sensitive Random Insulin Granule Diffusion is a Prerequisite for Recruiting Granules for Release.
(2004) In Traffic: the International Journal of Intracellular Transport 5(10). p.750-762- Abstract
- Glucose-evoked insulin secretion exhibits a biphasic time course and is associated with accelerated intracellular granule movement. We combined live confocal imaging of EGFP-labelled insulin granules with capacitance measurements of exocytosis in clonal INS-1 cells to explore the relation between distinct random and directed modes of insulin granule movement, as well as exocytotic capacity. Reducing the temperature from 34 °C to 24 °C caused a dramatic 81% drop in the frequency of directed events, but reduced directed velocities by a mere 25%. The much stronger temperature sensitivity of the frequency of directed events (estimated energy of activation ~ 135 kJ/mol) than that of the granule velocities (~ 22 kJ/mol) suggests that... (More)
- Glucose-evoked insulin secretion exhibits a biphasic time course and is associated with accelerated intracellular granule movement. We combined live confocal imaging of EGFP-labelled insulin granules with capacitance measurements of exocytosis in clonal INS-1 cells to explore the relation between distinct random and directed modes of insulin granule movement, as well as exocytotic capacity. Reducing the temperature from 34 °C to 24 °C caused a dramatic 81% drop in the frequency of directed events, but reduced directed velocities by a mere 25%. The much stronger temperature sensitivity of the frequency of directed events (estimated energy of activation ~ 135 kJ/mol) than that of the granule velocities (~ 22 kJ/mol) suggests that cooling-induced suppression of insulin granule movement is attributable to factors other than reduced motor protein adenosine 5'-triphosphatase activity. Indeed, cooling suppresses random granule diffusion by ~ 50%. In the single cell, the number of directed events depends on the extent of granule diffusion. Finally, single-cell exocytosis exhibits a biphasic pattern corresponding to that observed in vivo, and only the component reflecting 2nd phase insulin secretion is affected by cooling. We conclude that random diffusive movement is a prerequisite for directed insulin granule transport and for the recruitment of insulin granules released during 2nd phase insulin secretion. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/127530
- author
- Ivarsson, Rosita LU ; Obermüller, Stefanie LU ; Rutter, Guy A ; Galvanovskis, Juris LU and Renström, Erik LU
- organization
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Traffic: the International Journal of Intracellular Transport
- volume
- 5
- issue
- 10
- pages
- 750 - 762
- publisher
- Wiley-Blackwell
- external identifiers
-
- wos:000223748400003
- pmid:15355511
- scopus:4744371528
- pmid:15355511
- ISSN
- 1398-9219
- DOI
- 10.1111/j.1600-0854.2004.00216.x
- language
- English
- LU publication?
- yes
- id
- 31e5f1bd-a4e6-4a4d-9882-e8e6db59f82f (old id 127530)
- date added to LUP
- 2016-04-01 12:02:00
- date last changed
- 2022-04-21 01:25:28
@article{31e5f1bd-a4e6-4a4d-9882-e8e6db59f82f,
abstract = {{Glucose-evoked insulin secretion exhibits a biphasic time course and is associated with accelerated intracellular granule movement. We combined live confocal imaging of EGFP-labelled insulin granules with capacitance measurements of exocytosis in clonal INS-1 cells to explore the relation between distinct random and directed modes of insulin granule movement, as well as exocytotic capacity. Reducing the temperature from 34 °C to 24 °C caused a dramatic 81% drop in the frequency of directed events, but reduced directed velocities by a mere 25%. The much stronger temperature sensitivity of the frequency of directed events (estimated energy of activation ~ 135 kJ/mol) than that of the granule velocities (~ 22 kJ/mol) suggests that cooling-induced suppression of insulin granule movement is attributable to factors other than reduced motor protein adenosine 5'-triphosphatase activity. Indeed, cooling suppresses random granule diffusion by ~ 50%. In the single cell, the number of directed events depends on the extent of granule diffusion. Finally, single-cell exocytosis exhibits a biphasic pattern corresponding to that observed in vivo, and only the component reflecting 2nd phase insulin secretion is affected by cooling. We conclude that random diffusive movement is a prerequisite for directed insulin granule transport and for the recruitment of insulin granules released during 2nd phase insulin secretion.}},
author = {{Ivarsson, Rosita and Obermüller, Stefanie and Rutter, Guy A and Galvanovskis, Juris and Renström, Erik}},
issn = {{1398-9219}},
language = {{eng}},
number = {{10}},
pages = {{750--762}},
publisher = {{Wiley-Blackwell}},
series = {{Traffic: the International Journal of Intracellular Transport}},
title = {{Temperature-Sensitive Random Insulin Granule Diffusion is a Prerequisite for Recruiting Granules for Release.}},
url = {{https://lup.lub.lu.se/search/files/2751926/624089.pdf}},
doi = {{10.1111/j.1600-0854.2004.00216.x}},
volume = {{5}},
year = {{2004}},
}