Review Question - QID 214519

A scientist is studying the function of a protein that is defective in a rare early onset form of neurodegeneration. She finds that this protein is covalently attached to proteins on lysine residues. She then performs a pulse-chase experiment where she adds a radiolabeled version of this protein to a mixture. She finds that the radiolabeled protein is incorporated transiently into a diverse array of other proteins. Using western blot analysis, she also discovers that this protein appears to remain intact even after its modified target disappears from the mixture. Which of the following diseases involves decreased ability of this protein to perform its normal function?