The diagram below shows the GPCR signaling pathway leading t…
The diagram below shows the GPCR signaling pathway leading to gene expression. (What’s shown in this figure: A signal molecule binds to a GPCR on the plasma membrane → the activated GPCR acts as a GEF for G-alpha, causing G-alpha to drop GDP and pick up GTP → activated G-alpha binds to and activates adenylyl cyclase → adenylyl cyclase converts ATP to cyclic AMP (cAMP) → cAMP activates Protein Kinase A (PKA) → activated PKA enters the nucleus and phosphorylates CREB → phosphorylated CREB binds to cAMP response elements on DNA → genes promoting cell growth and division are expressed.) A mutation occurs in a cell that causes adenylyl cyclase to be permanently inactive. What would you expect to happen to this signaling pathway downstream of this mutation? (This is NOT a trick question — I want to make sure that you can examine a figure of a signaling pathway and determine what would happen to the pathway if something in it changes).