You are interested in further understanding the signal transduction pathway that controls the production of Pig1, a protein important for regulating cell size.Activation of the TRK receptor leads to activation of the GTP-binding protein, Ras, which then activates a protein kinase that phosphorylates the SZE transcription factor.SZE only interacts with the nuclear transport receptor when it is phosphorylated.SZE is a gene activator for the Pig1 gene.This pathway is diagrammed in Figure 16-25. Figure 16-25
Normal cells grown under standard conditions (without ligand) are 14 μm in diameter while normal cells exposed to TRK ligand are 10.5 μm in diameter.Given this situation, which of the following conditions do you predict will more likely lead to smaller cells?

Question

You are interested in further understanding the signal transduction pathway that controls the production of Pig1, a protein important for regulating cell size.Activation of the TRK receptor leads to activation of the GTP-binding protein, Ras, which then activates a protein kinase that phosphorylates the SZE transcription factor.SZE only interacts with the nuclear transport receptor when it is phosphorylated.SZE is a gene activator for the Pig1 gene.This pathway is diagrammed in Figure 16-25.  Figure 16-25
Normal cells grown under standard conditions (without ligand) are 14 μm in diameter while normal cells exposed to TRK ligand are 10.5 μm in diameter.Given this situation, which of the following conditions do you predict will more likely lead to smaller cells?

Quizplus · Accepted Answer

Activation of TRK receptor leads to activation of Ras which then activates a protein kinase that phosphorylates the SZE transcription factor. SZE only interacts with the nuclear transport receptor when it is phosphorylated. SZE is a gene activator for the Pig1 gene. In normal cells grown under standard conditions (without ligand), the size of the cell is 14 µm, but normal cells exposed to TRK ligand are 10.5 µm. If a drug that inhibits the activity of the phosphatase that acts on SZE is added along with TRK ligand, it leads to increased phosphorylation and activation of SZE transcription factor. This will lead to higher expression of Pig1 gene, which in turn will lead to the regulation of cell size, thereby resulting in smaller cells.

You Are Interested in Further Understanding the Signal Transduction Pathway