Insulin promotes Rip11 accumulation at the plasma membrane by inhibiting a dynamin- and PI3-kinase-dependent, but Akt-independent, internalisation event

• Published in: Cellular signalling 2016-01, Vol.28 (1), p.74-82
• Main Authors: Boal, Frédéric, Hodgson, Lorna R., Reed, Sam E., Yarwood, Sophie E., Just, Victoria J., Stephens, David J., McCaffrey, Mary W., Tavaré, Jeremy M.
• Format: Article
• Language: English
• Subjects: Adipocytes - metabolism; Animals; Carrier Proteins - metabolism; Cell Membrane - metabolism; Endocytosis; Glucose Transporter Type 4 - metabolism; Insulin; Insulin - metabolism; Insulin - pharmacology; Mice; Mitochondrial Proteins - metabolism; Phosphatidylinositol 3-Kinases - drug effects; Phosphatidylinositol 3-Kinases - metabolism; Phosphorylation; Protein Transport - drug effects; Protein Transport - physiology; Proto-Oncogene Proteins c-akt - metabolism; Rab; rab GTP-Binding Proteins; Recycling; Rip11
• ISSN: 0898-6568; 1873-3913
• DOI: 10.1016/j.cellsig.2015.10.014

Rip11 is a Rab11 effector protein that has been shown to be important in controlling the trafficking of several intracellular cargoes, including the fatty acid transporter FAT/CD36, V-ATPase and the glucose transporter GLUT4. We have previously demonstrated that Rip11 translocates to the plasma membrane in response to insulin and here we examine the basis of this regulated phenomenon in more detail. We show that Rip11 rapidly recycles between the cell interior and surface, and that the ability of insulin to increase the appearance of Rip11 at the cell surface involves an inhibition of Rip11 internalisation from the plasma membrane. By contrast the hormone has no effect on the rate of Rip11 translocation towards the plasma membrane. The ability of insulin to inhibit Rip11 internalisation requires dynamin and class I PI3-kinases, but is independent of the activation of the protein kinase Akt; characteristics which are very similar to the mechanism by which insulin inhibits GLUT4 endocytosis. •Rip11 translocates constitutively to the plasma membrane on Rab11-vesicles.•Inhibition of Rip11 internalisation by insulin requires dynamin.•Rip11 accumulation at the plasma membrane is PI3-K dependent but Akt-independent.