Activated protein kinase C (PKC) can lead to the modification of the membrane lipids in the vicinity of the active PKC.Figure 16-17 shows how G proteins can indirectly activate PKC.You have discovered the enzyme activated by PKC that mediates the lipid modification.You call the enzyme Rafty and demonstrate that activated PKC directly phosphorylates Rafty, activating it to modify the plasma membrane lipids in the vicinity of the cell where PKC is active; these lipid modifications can be detected by dyes that bind to the modified lipids.Cells lacking Rafty do not have these modifications, even when PKC is active.Which of the following conditions would lead to signal-independent modification of the membrane lipids by Rafty? Figure 16-17

Question

Activated protein kinase C (PKC) can lead to the modification of the membrane lipids in the vicinity of the active PKC.Figure 16-17 shows how G proteins can indirectly activate PKC.You have discovered the enzyme activated by PKC that mediates the lipid modification.You call the enzyme Rafty and demonstrate that activated PKC directly phosphorylates Rafty, activating it to modify the plasma membrane lipids in the vicinity of the cell where PKC is active; these lipid modifications can be detected by dyes that bind to the modified lipids.Cells lacking Rafty do not have these modifications, even when PKC is active.Which of the following conditions would lead to signal-independent modification of the membrane lipids by Rafty?  Figure 16-17

Quizplus · Accepted Answer

A constitutively active phospholipase C will lead to the constitutive production of IP₃ and diacylglycerol, leading to activation of PKC in a signal-independent manner; thus, Rafty activation and the lipid modification will be signal-independent.A mutation in the GPCR that bind the signal more tightly and a Ca²⁺ channel with an increased affinity for IP will increase activity of the signal transduction pathway in a signal-dependent manner.A mutation that renders Rafty such that it can no longer by phosphorylated by PKC will prevent PKC from activating Rafty and will thus prevent the lipid modifications.

Activated Protein Kinase C (PKC) Can Lead to the Modification