Mutant prion proteins are partially retained in the endoplasmic reticulum

Author(s): Ivanova L, Barmada S, Kummer T, Harris DA


Familial prion diseases are linked to point and insertional mutations in the prion protein (PrP) gene that are presumed to favor conversion of the cellular isoform of PrP to the infectious isoform. In this report, we have investigated the subcellular localization of PrP molecules carrying pathogenic mutations using immunofluorescence staining, immunogold labeling, and PrP-green fluorescent protein chimeras. To facilitate visualization of the mutant proteins, we have utilized a novel Sindbis viral replicon engineered to produce high protein levels without cytopathology. We demonstrate that several different pathogenic mutations have a common effect on the trafficking of PrP, impairing delivery of the molecules to the cell surface and causing a portion of them to accumulate in the endoplasmic reticulum. These observations suggest that protein quality control in the endoplasmic reticulum may play an important role in prion diseases, as it does in some other inherited human disorders. Our experiments also show that chimeric PrP molecules with the sequence of green fluorescent protein inserted adjacent to the glycolipidation site are post-translationally modified and localized normally, thus documenting the utility of these constructs in cell biological studies of PrP.

Similar Articles

Internalization of mammalian fluorescent cellular prion protein and N-terminal deletion mutants in living cells

Author(s): Lee KS, Magalhães AC, Zanata SM, Brentani RR, Martins VR, et al.

Endocytic intermediates involved with the intracellular trafficking of a fluorescent cellular prion protein

Author(s): Magalhães AC, Silva JA, Lee KS, Martins VR, Prado VF, et al.

Scrapie-infected murine neuroblastoma cells produce protease-resistant prion proteins

Author(s): Butler DA, Scott MR, Bockman JM, Borchelt DR, Taraboulos A, et al.

Anterograde and retrograde intracellular trafficking of fluorescent cellular prion protein

Author(s): Hachiya NS, Watanabe K, Yamada M, Sakasegawa Y, Kaneko K

Prion protein is necessary for normal synaptic function

Author(s): Collinge J, Whittington MA, Sidle KC, Smith CJ, Palmer MS, et al.

The cellular prion protein binds copper in vivo

Author(s): Brown DR, Qin K, Herms JW, Madlung A, Manson J, et al.

Evidence for the involvement of KIF4 in the anterograde transport of L1-containing vesicles

Author(s): Peretti D, Peris L, Rosso S, Quiroga S, Cáceres A

Glutamate-receptor-interacting protein GRIP1 directly steers kinesin to dendrites

Author(s): Setou M, Seog DH, Tanaka Y, Kanai Y, Takei Y, et al.

Molecular motors: strategies to get along

Author(s): Mallik R, Gross SP

Movement of microtubules by single kinesin molecules

Author(s): Howard J, Hudspeth AJ, Vale RD