title: Real-time measurement of F-actin remodelling during exocytosis using Lifeact-EGFP transgenic animals.
abstract: F-actin remodelling is essential for a wide variety of cell processes. It is important in exocytosis, where F-actin coats fusing exocytic granules. The purpose of these F-actin coats is unknown. They may be important in stabilizing the fused granules, they may play a contractile role and promote expulsion of granule content and finally may be important in endocytosis. To elucidate these functions of F-actin remodelling requires a reliable method to visualize F-actin dynamics in living cells. The recent development of Lifeact-EGFP transgenic animals offers such an opportunity. Here, we studied the characteristics of exocytosis in pancreatic acinar cells obtained from the Lifeact-EGFP transgenic mice. We show that the time-course of agonist-evoked exocytic events and the kinetics of each single exocytic event are the same for wild type and Lifeact-EGFP transgenic animals. We conclude that Lifeact-EGFP animals are a good model to study of exocytosis and reveal that F-actin coating is dependent on the de novo synthesis of F-actin and that development of actin polymerization occurs simultaneously in all regions of the granule. Our insights using the Lifeact-EGFP mice demonstrate that F-actin coating occurs after granule fusion and is a granule-wide event.
authors: School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia.
authors: Yujin
authors: Y
authors: Jang
authors: Carolina
authors: C
authors: Soekmadji
authors: Justin M
authors: JM
authors: Mitchell
authors: Walter G
authors: WG
authors: Thomas
authors: Peter
authors: P
authors: Thorn
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D005089:Exocytosis / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal / Q000379:methods; D010179:Pancreas / Q000166:cytology* / Q000378:metabolism*; D022142:Secretory Vesicles / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins