Dynamin is functionally coupled to insulin granule exocytosis

Le Min, Yuk M. Leung, Alejandra Tomas, Robert T. Watson, Herbert Y. Gaisano, Philippe A. Halban, Jeffrey E. Pessin, June Chunqiu Hou

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28 Scopus citations

Abstract

The insulin granule integral membrane protein marker phogrin-green fluorescent protein was co-localized with insulin in Min6B1 β-cell secretory granules but did not undergo plasma membrane translocation following glucose stimulation. Surprisingly, although expression of a dominant-interfering dynamin mutant (Dyn/K44A) inhibited transferrin receptor endocytosis, it had no effect on phogringreen fluorescent protein localization in the basal or secretagogue-stimulated state. By contrast, co-expression of Dyn/K44A with human growth hormone as an insulin secretory marker resulted in a marked inhibition of human growth hormone release by glucose, KCl, and a combination of multiple secretagogues. Moreover, serial pulse depolarization stimulated an increase in cell surface capacitance that was also blocked in cells expressing Dyn/K44A. Similarly, small interference RNA-mediated knockdown of dynamin resulted in marked inhibition of glucose-stimulated insulin secretion. Together, these data suggest the presence of a selective kiss and run mechanism of insulin release. Moreover, these data indicate a coupling between endocytosis and exocytosis in the regulation of β-cell insulin secretion.

Original languageEnglish (US)
Pages (from-to)33530-33536
Number of pages7
JournalJournal of Biological Chemistry
Volume282
Issue number46
DOIs
StatePublished - Nov 16 2007

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ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Min, L., Leung, Y. M., Tomas, A., Watson, R. T., Gaisano, H. Y., Halban, P. A., Pessin, J. E., & Hou, J. C. (2007). Dynamin is functionally coupled to insulin granule exocytosis. Journal of Biological Chemistry, 282(46), 33530-33536. https://doi.org/10.1074/jbc.M703402200