Prion-Like Protein Involved in Memory Storage

A study exploring how memories are stored has found that a key player in the process is a protein that behaves like a prion, contradicting the belief that a protein that has prion activity is toxic or does not function properly. The findings were reported in the December 26, 2003, issue of Cell.

Researchers were surprised to find that a protein related to maintaining long-term memory contained certain prion signatures. This protein, CPEB, resides in the central-nervous-system synapses. Memories are contained within that intricate network of approximately one trillion neurons and their synapses. As learning and experience take place, new junctions form. CPEB synthesizes proteins that strengthen such synapses as memories are formed, enabling the synapses to retain the memories over long periods.

Using the CPEB of a sea slug, the researchers found that CPEB altered its form and caused other proteins to follow, functioning exactly like a prion. Another finding was that CPEB carried out its normal function, protein synthesis, when it was in a prion state. The finding contradicts the notion that converting to a prion state is a bad thing.

"This is remarkable not just because the protein executes a positive function in its prion-like state,” said coauthor Susan Lundquist, of the Whitehead Institute for Biomedical Research (Cambridge, MA, USA). "It also indicates that prions aren't just oddballs of nature but might participate in fundamental processes.” Dr. Lundquist also noted that prions could shift into this state quickly without the energy-intensive cellular mechanics that fuel most protein synthesis. The prion state is very stable, she added, and can maintain itself for months, even years.




Related Links:
Whitehead