PROBLEM SET 3 1.You have obtained immortalized liver cells from a patient who died of Wilson’s disease, an inherited disorder of copper metabolism marked by neuronal degeneration and hepatic cirrhosis. The Wilson protein is a copper-transporting P-type ATPase that localizes to the trans Golgi network. People with this disease have a mutant (and thus misfolded) version of this copper transporter in the ER. A) It is unclear if this mutant protein is non-functional or if this mutant triggers the unfolded protein response. Design an experiment that could determine this. B) There are several chaperone proteins in the ER. You would like to know if BiP binds the Wilson protein. You find that you can isolate some Wilson protein bound to BiP when ADP is added to the cell extracts but not when ATP is added to the extract. Explain this result based on the mechanism for BiP binding substrate proteins. C) You over express a mutant form of IRE-1 that does not bind BiP. Would this make the Wilson phenotype (i.e. the degradation of Wilson protein) more severe or less severe? Explain your reasoning. D) You discover that if the transcription factor Hac1 is not activated, the Wilson protein will be transported to its proper location and function normally. Considering the mechanism of Hac1 activation, describe two ways you could inhibit Hac1’s function.
has intentionally blurred sections.
Sign up to view the full version.