Good news for prions?
Mad cow and memory: Prion-like proteins proposed to regulate neuronal plasticity By Brendan A Maher
Since their discovery in 1982, prions have been mostly associated with deadly and devastating
neurodegenerative disorders-notably variant Creutzfeld-Jakob disease and bovine spongiform
encephalopathy. Nevertheless, some maintain that the mechanism by which prions change their shape
and aggregate might be put to good use in biological systems. In back-to-back papers in the December
26 issue of Cell, researchers ascribe prion-like properties to an elegant mechanism involved in
maintaining memory.
Susan Lindquist, director of the Massachusetts Institute of Technology's Whitehead Institute, and
Eric Kandel, professor of physiology and psychiatry at Columbia University College of Physicians and
Surgeons, describe a protein, cytoplasmic polyadenylation element-binding protein (CPEB), which
appears to mark active synapses. The protein behaves like a prion in yeast cultures, and its
alternative self-perpetuating form-generally associated with disease states for other prions-appears
to be the protein's active form.
Researchers, in looking to understand memory formation, have struggled to comprehend how a neuron
can strengthen specific synapses while leaving others alone. Kandel, who shared the 2000 Nobel Prize
for work on neuronal signaling, has shown that protein synthesis, localized to the dendrites,
enables a function known as long-term facilitation, which is a strengthening of synaptic connections
in the large neurons of the sea slug Aplysia californica.
In the Cell papers, he proposes that CPEB maintains that strengthening process by spurring local
translation of ubiquitous but dormant messages, such as those for structural and regulatory
molecules, which allow a synapse to grow. "It takes sleeping messenger RNAs and it wakes them up,"
Kandel told The Scientist.
Read the rest at The Scientist.com biomedcentral.com02Open ↗
Posted by Robert Karl Stonjek.