Autolytic activation and localization in Schneider cells (S2) of calpain B from Drosophila.

TitleAutolytic activation and localization in Schneider cells (S2) of calpain B from Drosophila.
Publication TypeJournal Article
Year of Publication2004
AuthorsFarkas, A., P. Tompa, E. Schad, R. Sinka, G. Jékely, and P. Friedrich
JournalBiochem J
Volume378
IssuePt 2
Pagination299-305
Date Published2004 Mar 1
ISSN1470-8728
KeywordsAmino Acid Sequence, Animals, Calpain, Cell Line, Cytoplasm, Drosophila melanogaster, Drosophila Proteins, Enzyme Activation, Intracellular Membranes, Molecular Sequence Data, RNA, Messenger
Abstract

Calpain B is one of the two calpain homologues in Drosophila melanogaster that are proteolytically active. We studied its activation by Ca2+ both in vitro and in vivo, in Schneider (S2) cells. Activation involves the autolytic cleavage, at two major sites, of the N-terminal segment, the length of which was earlier underestimated. Site-directed mutagenesis at the autolytic sites did not prevent autolysis, but only shifted its sites. Calpain B mRNA was detectable in all developmental stages of the fly. In situ hybridization and immunostaining showed expression in ovaries, embryo and larvae, with high abundance in larval salivary glands. In S2 cells, calpain B was mainly in the cytoplasm and upon a rise in Ca2+ the enzyme adhered to intracellular membranes.

DOI10.1042/BJ20031310
Alternate JournalBiochem. J.
PubMed ID14614768
PubMed Central IDPMC1223968