Unconventional myosin Myo1c promotes membrane fusion in a regulated exocytic pathway
Authors
Bose, AvirupRobida, Stacey I.
Furcinitti, Paul S.
Chawla, Anil
Fogarty, Kevin E.
Corvera, Silvia
Czech, Michael P.
Document Type
Journal ArticlePublication Date
2004-06-01Keywords
1-Phosphatidylinositol 3-Kinase3T3-L1 Cells
Adipocytes
Animals
Chromones
Enzyme Inhibitors
Exocytosis
Glucose Transporter Type 4
Insulin
Membrane Fusion
Mice
Molecular Motor Proteins
Monosaccharide Transport Proteins
Morpholines
*Muscle Proteins
Myosins
Recombinant Fusion Proteins
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
Glucose homeostasis is controlled in part by regulation of glucose uptake into muscle and adipose tissue. Intracellular membrane vesicles containing the GLUT4 glucose transporter move towards the cell cortex in response to insulin and then fuse with the plasma membrane. Here we show that the fusion step is retarded by the inhibition of phosphatidylinositol (PI) 3-kinase. Treatment of insulin-stimulated 3T3-L1 adipocytes with the PI 3-kinase inhibitor LY294002 causes the accumulation of GLUT4-containing vesicles just beneath the cell surface. This accumulation of GLUT4-containing vesicles near the plasma membrane prior to fusion requires an intact cytoskeletal network and the unconventional myosin motor Myo1c. Remarkably, enhanced Myo1c expression under these conditions causes extensive membrane ruffling and overrides the block in membrane fusion caused by LY294002, restoring the display of GLUT4 on the cell exterior. Ultrafast microscopic analysis revealed that insulin treatment leads to the mobilization of GLUT4-containing vesicles to these regions of Myo1c-induced membrane ruffles. Thus, localized membrane remodeling driven by the Myo1c motor appears to facilitate the fusion of exocytic GLUT4-containing vesicles with the adipocyte plasma membrane.Source
Mol Cell Biol. 2004 Jun;24(12):5447-58. Link to article on publisher's siteDOI
10.1128/MCB.24.12.5447-5458.2004Permanent Link to this Item
http://hdl.handle.net/20.500.14038/38553PubMed ID
15169906Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1128/MCB.24.12.5447-5458.2004