Prefoldin is a
molecular chaperone that assists the folding of newly synthesized
polypeptide chains and prevents aggregation of misfolded
proteins. Dysfunction of
prefoldin is one of the causes of
neurodegenerative diseases such as
Alzheimer's disease. The aim of this study was to clarify the involvement of
prefoldin subunit 5 (PFDN5) in synaptic plasticity. PFDN5
protein expressed in the hippocampus was predominantly localized in the pyramidal cell layer of CA1-CA3 regions.
Nicotine application caused a long-term potentiation (LTP)-like facilitation in vivo, that is synaptic plasticity, in the mouse hippocampus. The levels of PFDN5
mRNA and
protein were increased 2-24 h and 4-24 h, respectively, after intraperitoneal application of
nicotine (3 mg/kg, i.p.), finally returning to the basal level. This increase of PFDN5
protein was significantly inhibited by
mecamylamine (0.5 mg/kg, i.p.), a non-selective
nicotinic acetylcholine receptors (nAChRs) antagonist, and required combined application of
ABT-418 (10 mg/kg, i.p.), a selective α4β2 nAChR agonist, and
choline (30 mg/kg, i.p.), a selective α7 nAChR agonist. In transgenic mice overexpressing human tau with N279 K mutation as a model of
Alzheimer's disease that showed impaired synaptic plasticity, the levels of PFDN5
mRNA and
protein in the hippocampus were significantly decreased in an age-dependent manner as compared with age-matched control. The findings demonstrated that the level of PFDN5
protein in the hippocampus was changed depending on the situation of synaptic plasticity. We propose that PFDN5 could be one of the important components of synaptic plasticity.