I'm going through medical exam sample papers and am really stuck on one question, which involves a diagram and multiple choice answers. I've searched in many textbooks and online, and yet can't get much info on it.
More than one answer may be correct for any line.
Diagram:
The diagram above illustrates a signalling pathway that is hyperactive in breast cancer cells. Each label A-L indicates a protein. Identify the protein(s) that are described below.
1. One protein whose absence will tend to cause cells to divide (that is, the product of a tumour suppressor gene).
2. One protein that is not synthesized by the parental, non-tumour cells but which is often expressed by breast cancer cells.
3. One protein that binds to DNA. (I believe this is L, but maybe others also?)
4. One protein that is often mutated in cancers in such a way that its ability to activate the downstream target is maintained for a much longer time than is the case for the normal protein.
5. One or more proteins (without kinase catalytic activity) that bind to a second, target protein. The target protein, a kinase, is inactive unless the indicated protein(s) is/are found.
Any help, or a point in the right direction, would be greatly appreciated!
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