You are studying the responses of myocytes in culture to the addition of insulin. Normally in myocytes when insulin binds, several proteins are phosphorylated by kinases. You discover that several target proteins are not appropriately modified in your cells. Which of the following is most likely not occurring in your cell culture in response to insulin thereby, explaining the lack of target protein phosphorylation? A) action of a G-protein in the plasma membrane B) release of Ca²⁺ from the endoplasmic reticulum C) release of diacylglycerol from phosphatidylinositol D) translocation of the glucose transporter to the plasma membrane E) tyrosine kinase activity of the insulin receptor

Question

Quizplus · Accepted Answer

The lack of target protein phosphorylation in response to insulin is most likely due to the absence of tyrosine kinase activity of the insulin receptor, as this activity is crucial for initiating the signaling cascade that leads to protein phosphorylation.

You Are Studying the Responses of Myocytes in Culture to the Addition