Cells can adapt to extracellular signal molecules in a variety of ways. Interestingly, exposure to a signal molecule can sometimes not only desensitize the cell to this molecule, but also to one or more other signal molecules that are recognized by different receptors, even if those receptors can still bind to their ligand at the cell surface and initiate signaling. Which subset of the following adaptation mechanisms (for the original signal) can in principle account for this type of desensitization? Choose all that apply. Your answer would be a string composed of letters A to E only, in alphabetical order; e.g. BDE.
(A) Receptor sequestration
(B) Receptor down-regulation
(C) Receptor inactivation
(D) Inactivity of signaling protein
(E) Production of inhibitory protein