|MoBio||Signaling via Cell-Surface Enzymes||Chapter 6|
Signaling enzymes which are cell-surface receptors
Receptor tyrosine kinase
Receptor tyrosine kinases play a key role in cellular processes. A tyrosine kinase catalyzes the phosphorylation of tyrosine residues in a protein. The phosphorylated protein can then pass the signal to SH2-containing proteins.
Receptor serine/threonine kinase
Example: TGF-β. It is a growth factor with broad tissue distribution that plays critical roles during embryonic development, normal tissue homeostasis, and cancer (reference).
Receptor tyrosine phosphatase
It catalyzes the dephosphorylation of the tyrosine residue.
Receptor guanylyl cyclase
It catalyzes the synthesis of cGMP.
Signaling enzymes anchored on the cytosolic face of the plasma membrane
Non-receptor tyrosine kinases
Three major classes of non-receptor tyrosine kinases have been identified: Src, Abl and Jak.