Question

1. What is the SIMPLEST mechanism for an intracellular protein to integrate signals from two different kinase cascades?

2. Why might so many receptor kinases become active if expressed at very high levels (even in the absence of ligand) ?

3. The activation of a membrane bound receptor kinase by its ligand activates its kinase domain and often______

4. What does binding of its ligand do to a receptor kinase?

5. Types of membrane-bound receptors?

Answer 1

1. Phosphorylation is the simplest mechanisms which integrate signals from two different kinase cascades.

2. If receptor kinases become active when it undergoes mutation in the lignand binding domain of receptor. So, it constitutive express the receptor kinase even in the absence of ligand.

3. Activates the G protein which cascade the downstream kinases.

4. Binding of ligand makes a conformational changes in the receptor kinase which cross phorphorylate the receptor kinase for its activation.

5. G protein coupled receptor
Protein tryosine kinase receptor
Cytokine receptor and non receptor Protein tryosine kinase receptor
Transforming growth factor receptor