Prion protein fragment interacts with PrP-deficient cells

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• The prion protein (PrP) is implicated in neurodegenerative diseases.
• Prion protein fragment PrP106-126 induces toxicity in neuronal cells.
• The cellular targets and mechanisms of PrP106-126 toxicity are not fully understood.

Purpose of the Study:

• To identify cellular binding partners of the prion protein fragment PrP106-126.
• To investigate the role of these binding partners in PrP106-126-induced cellular toxicity.
• To elucidate the mechanism by which PrP106-126 affects neuronal cells, particularly in the absence of endogenous PrP.

Main Methods:

• Primary neuronal cultures from wild-type and PrP-null (PrPo/o) embryonic mice.
• Isolation and sequencing of PrP106-126 binding partners.
• Cell culture experiments using colchicine and taxol to assess toxicity modulation.

Main Results:

• Alpha and beta tubulin were identified as binding partners for PrP106-126.
• PrP106-126 enhanced colchicine toxicity in PrPo/o neurons, indicating interaction within cells.
• Taxol enhanced PrP106-126 toxicity in wild-type neurons, further supporting tubulin interaction.
• PrP106-126 demonstrated toxicity even in PrPo/o cells, suggesting a mechanism independent of native PrP interaction but dependent on PrP expression phenotype.

Conclusions:

• Prion protein fragment PrP106-126 directly binds to cellular tubulin.
• This binding alters cellular metabolism and induces toxicity, independent of endogenous PrP expression.
• The observed toxicity is linked to the loss of a PrP expression-dependent cellular phenotype.