FRQ 01 / 087 points total
Cell Communication & Cell CycleChange
Signal Transduction via a Receptor Tyrosine Kinase
A growth factor (a hydrophilic ligand) binds to a receptor tyrosine kinase (RTK) on the surface of a target cell. Binding initiates a signal transduction pathway that ultimately changes gene expression in the nucleus.
(a)Describe the events at the receptor when the ligand binds, including how the receptor becomes activated. [2 pts]
(b)Explain how the signal is transmitted from the activated receptor to the nucleus through a phosphorylation cascade. [2 pts]
(c)Identify ONE way the signal is amplified during transduction. [1 pt]
(d)Predict what would happen to the cellular response if a mutation made the RTK constitutively active (locked in the ON state) and justify how this could lead to cancer. [2 pts]