Purification of age-distinct insulin secretory granules through antigen restriction (original) (raw)

New Results

, Pia Sala, Andreas-David Brunner, Katharina Ganß, Alessandra Palladini, Michal Grzybek, View ORCID ProfileJovana Vasiljević, View ORCID ProfileJohannes Broichhagen, View ORCID ProfileKai Johnsson, View ORCID ProfileThomas Kurth, Matthias Mann, Ünal Coskun, View ORCID ProfileMichele Solimena

doi: https://doi.org/10.1101/2020.06.03.103770

Summary

Endocrine cells employ regulated exocytosis of secretory granules to secrete hormones and neurotransmitters. The competence of secretory granules for exocytosis depends on spatio-temporal variables such as proximity to the plasma membrane and age, with newly-generated granules being preferentially released. Despite recent advances, we still lack a comprehensive view about the molecular composition of insulin granules and how this may change over the lifetime of the organelles. Here we report a strategy for the purification of insulin secretory granules of distinct age from insulinoma INS-1 cells. Tagging the granule-resident protein phogrin with a cleavable CLIP tag, we obtained intact fractions of age-distinct granules for proteomic and lipidomic analyses. We find that the lipid composition changes over time along with the physical properties of the membrane.

Competing Interest Statement

The authors have declared no competing interest.

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