Viral Cancer Genes

After a ligand binds, there may be a g-protein bound to the part of the protein that's located within the cell. The ligand induces a conformational onto the transmembrane protein, causing the GDP to be replaced with GTP on the alpha subunit of the g-protein. This activates the alpha subunit, causing it to detach from the g-protein and activate ion channels near-by. For example, if the activated alpha subunit activates a calcium channel, calcium flows into the cell then it binds with calmodulin. Calmodulin is a multifunctional intermediate calcium-binding messenger protein, leading to changes further down in the pathway.

Another pathway following ligand binding are the activation of protein kinases. If you'd like me to elaborate on that, message me back...