Ahsg-fetuin blocks the metabolic arm of insulin action through its interaction with the 95-kD β-subunit of the insulin receptor

► Ahsg (fetuin-A) inhibits the metabolic arm of insulin action involving Akt. ► Ahsg inhibits trafficking of the insulin-sensitive glucose transporter GLUT4. ► Shows that Ahsg functions independently of the 120-kD insulin receptor α-subunit ► Define the target of Ahsg action as the external 194 residue segment of the ß-subunit ► Supports previous mouse knockout studies on insulin sensitivity and resistance