Insulin first binds to its receptor, which is present on the cell surface, and once it binds it
triggers autophosphorylation of the receptor.
Binding to ephrin ligands on the surface of neighboring cells induces canonical signaling involving receptor clustering,
autophosphorylation on tyrosine residues, and kinase activity - dependent downstream signaling.
Since we can show that the alpha receptor does not
undergo autophosphorylation in response to PDGF - AA, we believe the defect in the NG2 - negative cells must lie at the level of receptor activation.
This is due to
autophosphorylation of this receptor, which then recruits IRS - 1, IRS - 2 and some of the other substrates.
(B) RIPK2
autophosphorylation (Auto - P) at site Y474 is shown.
We can clearly observe RIPK2 inhibitor 1 and 2 inhibition of MDP - dependent activation of RIPK2
autophosphorylation (on tyrosine 474) using an in vitro kinase assay in HCT116 cells (Fig. 3B).