Question: HER2 (ErbB2) is a cell surface receptor tyrosine kinase. Binding of ligand (signal) leads to the …

HER2 (ErbB2) is a cell surface receptor tyrosine kinase. Binding
of ligand
(signal) leads to the formation of receptor dimers, which
cross-phosphorylate each
other. Phosphorylated receptor then triggers downstream effects. It
influences the
behavior of cells through the Ras-MAPK pathway (see Figure 23.9 of
Pierce), and
promotes cell division.
a. HER2 was also identified as a gene important in cancer, called
neu. Do you
predict HER2 was identified as an oncogene, or as a tumor
suppressor gene?
Explain the logic underlying your prediction.
b. Propose a mutation in or a variant of HER2 that might be
associated with
cancer. Be as specific as possible, given your understanding.
Explain the logic
underlying your proposal.