Articles

Article

Original

Exp Neurobiol 2003; 12(1): 51-55

Published online July 1, 2003

© The Korean Society for Brain and Neural Sciences

Differential Subsynaptic Distribution of BiP, ERp72 and Calnexin 88 in the Rat CNS Synapse

Myoung Kwon Choi1, O-Yu Kwon2, Wan Park1, Yong Wook Jung3, Bok Hyun Ko3 and Il Soo Moon3,*

1Department of Microbiology, College of Natural Sciences, Kyungpook National University, Daegu 702-701, Korea, 2Department of Anatomy, College of Medicine, Chungnam National University, Daejeon, Korea and 3Department of Anatomy, College of Medicine, Dongguk University, Gyeongju 780-714, Korea

Correspondence to: *To whom correspondence should be addressed.
TEL: 054-770-2414, FAX: 054-770-2447
e-mail: moonis@dongguk.ac.kr

Abstract

Long-lasting changes in synaptic efficacy require newly synthesized proteins being deposited at the synapses. Recent evidence indicates that protein synthesis can occur at or near synapses. In this study, we searched for molecular chaperones in the synapse by immunoblot analysis. BiP and calnexin 88 were present in both forebrain and cerebellar PSD fractions. However, ERp72 was associated only with forebrain PSD fraction. BiP and ERp72 were enriched by ∼2- and 7-fold in the synaptosome fraction compared to brain homogenates but weakly associated with the PSD. In contrast, calnexin 88 was enriched by ∼2- and ∼2.5-fold in the synaptosome and PSD fractions, respectively, compared to homogenates, indicating that calnexin is associated with the PSD. Our results indicate that chaperones are differentially distributed in the synapse, and that protein folding machinery is present at or near synapses.

Keywords: BiP, calnexin, chaperone, ERp72, synapse, immunoblot, PSD