Question

2. Which of the following statements about epidermal growth factor (EGF) is false? (a) EGF stimulates cell division after an injury (b) EGF is a local signal, meaning that it binds to target cells that are close to the site where it was secreted (c) The EGF receptor is the same receptor that is used by insulin, but it is expressed in a different location (d) A mutation that causes the EGF receptor to become overactive can cause cancer (e) Drugs have been developed to inhibit the EGF receptor to treat cancer

Answer 1

In this case, it is important to know some structural differences between the insulin receptor (IR) and the epidermal growth factor receptor (EGFR). In this context, both posses a tyrosine kinase activity. Additionally, both have the same arrangement of leucine and cysteine rich regions. However, they differ in the C-terminal regions. In the case of EGFR, it posses a second cysteine region. In the case of IG, it posses there fibronectin domains. So, the correct answer is (c) The EGF receptor is the same receptor that is used by insulin, but it is expressed in a different location