Objective: To order the components in a cell signaling pathway based on protein mutation data.
In a hypothetical pathway, Ras, protein X, and protein Y are all required for proper signaling.
Cells in situation (A) were mutated so they do not express protein X. They still express protein Y.
Cells in situation (B) were mutated so they do not express protein Y. They still express protein X.
“Overactive Ras” means that Ras was transfected into the cells and is overexpressed.
Make an observation and corresponding conclusion for situation (A) and situation (B). Alternatively, state the conclusion based on the evidence.
Use your conclusions (above) to order the pathway starting with the receptor (RTK). Your pathway must include Ras, protein X and protein Y.
Why was a signal molecule not necessary to cause a response (“signaling restored”) when Ras was transfected into the cells in situation (A)?
In the cAMP/ p-CREB dataset presented in class, what was the condition that did not require a signal molecule to cause a response? (see backside) Explain how the treatment worked without a signal.