Differential distribution of calpain small subunit 1 and 2 in rat brain.

TitleDifferential distribution of calpain small subunit 1 and 2 in rat brain.
Publication TypeJournal Article
Year of Publication2004
AuthorsFriedrich, P., H. Papp, K. Halasy, A. Farkas, B. Farkas, P. Tompa, and P. Kása
JournalEur J Neurosci
Volume19
Issue7
Pagination1819-25
Date Published2004 Apr
ISSN0953-816X
KeywordsAnimals, Brain, Calpain, Humans, Immunohistochemistry, Male, Microscopy, Immunoelectron, Protein Subunits, Rats, Rats, Sprague-Dawley, Sequence Analysis, Protein, Synaptophysin
Abstract

Calpains, the Ca(2+)-dependent thiol proteases, are abundant in the nervous tissue. The ubiquitous enzyme forms in mammals are heterodimers consisting of a specific, micro or m, large (catalytic) subunit and, apparently, a common small (regulatory) subunit (CSS1). Recently, however, we described a second form of small subunit (CSS2), which is of restricted occurrence [Schád, E., Farkas, A., Jékely, G., Tompa, P. & Friedrich, P. (2002) Biochem. J., 362, 383-388]. Here we analysed the distribution of immunoreactivity in various parts of rat brain against two anti-CSS1 and two anti-CSS2 antibodies by correlated light and electron microscopy. Remarkably, the antibodies showed differential distribution in various parts of rat cortex: anti-CSS1 reacted mainly with perikarya and dendrites, whereas anti-CSS2 was more prominent in axons. In serial sections CSS2 and synaptophysin gave very similar patterns, i.e. these epitopes seem to colocalize. Electron microscopy confirmed that CSS1 was mainly localized postsynaptically in dendrites and somata, whereas CSS2 was found presynaptically. The hypothesis is advanced that these distinct distributions of calpain subunits may be related to the transport of these enzymes in nerve cells.

DOI10.1111/j.1460-9568.2004.03313.x
Alternate JournalEur. J. Neurosci.
PubMed ID15078555