Peter HobothGlucose homeostasis in vertebrates is regulated by secretion and action of the peptide hormone insulin. Imbalance in insulin demands and supply leads to diabetes. Insulin is produced by the pancreatic beta-cells, stored in insulin secretory granules (SGs) and secreted upon glucose stimulation. Importantly, secretion of insulin SGs does not occur chronologically, as they were produced, but new SGs “jump the queue” and are secreted preferentially upon glucose stimulation of beta-cells. However, the mechanism underlying this phenomenon is not entirely clear. Another line of evidence suggests that new SGs are more mobile than their older counterparts. Also in this case, the principles governing the different mobility of age-distinct SGs remain undefined. Therefore, we exploit quantitative fluorescence microscopy to gain insight into the mechanisms governing different mobility of age-distinct insulin SGs in living cells.
To fluorescently visualize age-distinct SGs in living cells we use insulin-SNAP reporter (Ivanova et al., 2012) and total internal reflection fluorescence microscopy (TIRFM). For the quantitative analysis of TIRFM data we collaborate with Yannis Kalaidzidis (Zerial lab, MPI-CBG Dresden http://www.mpi-cbg.de/research/research-groups/marino-zerial/research-focus.html). To study the morphology of age-distinct SGs at the ultrastructural level we collaborate within the lab with Andreas Müller, who exploits correlative light-electron microscopy. Moreover, to model the dynamics of insulin SGs in silico we collaborate with theoretical biologists Jaber Dehghany and Michael Meyer-Hermann from Helholtz Center in Braunschweig (http://www.helmholtz-hzi.de/en/research/research_topics/immune_response/systems_immunology/our_research/).
2007 BSc Molecular biology and biochemistry
2009 MSc Molecular biology, genetics and virology
2013 PhD Cell biology
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