Premium
Differential distribution of calpain small subunit 1 and 2 in rat brain
Author(s) -
Friedrich Peter,
Papp Henrietta,
Halasy Katalin,
Farkas Attila,
Farkas Bence,
Tompa Peter,
Kása Peter
Publication year - 2004
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2004.03313.x
Subject(s) - calpain , protein subunit , neuroscience , distribution (mathematics) , differential (mechanical device) , microbiology and biotechnology , biophysics , chemistry , biology , physics , mathematics , biochemistry , mathematical analysis , enzyme , gene , thermodynamics
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, µ 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.