In lung tumors in cigarette smokers, a mutation that is commonly found is a mutation in the ras gene that prevents the Ras protein from hydrolyzing GTP. Look back at the intracellular signaling pathway involving EGF shown in Figure 25.2. How would such a mutation affect cell growth?

Figure 25.2:

Transcribed Image Text:

Epidermal cell EGF receptor EGF Sos Ras GRB2 GDP Raf-1 MEK MAPK GRB2 Ras Raf-1 GTP GDP MEK MAPK Exposure to EGF Jun Jun Myc Fos Pathway off Pathway on Fos -P