|
||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520-8002
An early event in the Trypanosoma cruzi cell
invasion process, the recruitment of host lysosomes, led
us to investigate the involvement of signal transduction.
Infective trypomastigotes were found to contain a soluble Ca2+-signaling activity for mammalian cells that is
sensitive to protease inhibitors. Inhibitor and substrate
utilization profiles were used to purify a candidate peptidase for involvement in this process, from which we
isolated a full-length cDNA clone. The sequence revealed a novel enzyme, denominated T. cruzi oligopeptidase B, which is homologous to members of the prolyl
oligopeptidase family of serine hydrolases, known to
participate in the maturation of biologically active peptides. The T. cruzi oligopeptidase B was expressed as a
fully active product in Escherichia coli, and antibodies to the recombinant enzyme inhibited both peptidase
activity and Ca2+ signaling induced in normal rat kidney cells by trypomastigote extracts. Our data suggest
that the T. cruzi oligopeptidase B participates in processing events in the cytoplasm of the parasites, generating a factor with Ca2+-signaling activity for mammalian cells.
This article has been cited by other articles:
|
|