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Discussing the RAS Protein

Question: You are given a mutant cell that lacks the GTPase activating protein. What abnormalities would one expect to find in the way that RAS activity responds to extra-cellular signals? Why?

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Ras is a relatively small, globular, monomeric GTP/GDP-binding protein. It has a molecular weight of about 21 kDa and comprises 189 amino acid residues. Its main function is to regulate processes that affect cell transformation such as growth, differentiation and apoptosis. How does Ras work? It acts as a molecular switch, switching between an "off" and an "on" state. In its off state it is found in a complex with GDP, and in its on state it has a molecule of GTP bound to it. Simply put, Ras is turned on by removing the GDP and replacing it with a GTP. This nucleotide ...

Solution Summary

In about 385 words, this solution discusses the RAS protein, in terms of how this protein functions and abnormalities related to its activity.