IMGU in muscle. In the absence of fatty acids, when insulin (I) binds to its receptor (IR), the sequence of events are as
follows (dotted arrows). A: phosphorylation of the IRS-1 on a tyrosine residue, B: activation of phosphatidylinositol 3-kinase (PI3-K), and C: translocation of GLUT4 (G-4) to the membrane. In the presence of LCACoA, the insulin signaling cascade follows an abnormal
pathway (solid arrows). D: generation of a diacylglycerol (DAG) pool; E: activation of PKCθ and phosphorylation of IRS-1 on a serine residue. This model is supported by work published by the laboratories
of Shulman (18) and Kraegen (29).