Joseph Schlessinger
Types of receptor
Receptors can be roughly divided into two major classes:
- Intracellular receptors and
- Cell-surface receptors.
Ligand-gated ion channel receptors are a class of receptor that may occur both at the cell-surface or intracellularly.
Receptors that are solely intracellular include those for steroid hormones, retinoic acid, and derivatives of vitamin D3. In contrast to ligands that bind to cell surface receptors, in order to initiate signal transduction these ligands must cross the cell membrane.