Heritable disorder resembling neuronal storage disease in mice expressing prion protein with deletion of an alpha-helix.

Mice were constructed carrying prion protein (PrP) transgenes with individual regions of putative secondary structure deleted. Transgenic mice with amino-terminal regions deleted remained healthy at >400 days of age, whereas those with either of carboxy-terminal alpha-helices deleted spontaneously developed fatal CNS illnesses similar to neuronal storage diseases. Deletion of either C-terminal helix resulted in PrP accumulation within cytoplasmic inclusions in enlarged neurons. Deletion of the penultimate C-terminal helix resulted in proliferation of rough endoplasmic reticulum. Mice with the C-terminal helix deleted were affected with nerve cell loss in the hippocampus and proliferation of smooth endoplasmic reticulum. Whether children with the human counterpart of this malady will be found remains to be determined.