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Two secreted cystatins of the soft tick Ornithodoros moubata: differential expression pattern and inhibitory specificity.

Two secreted cystatins of the soft tick Ornithodoros moubata: differential expression pattern and inhibitory specificity.

Authors :
Grunclová L
Horn M
Vancová M
Sojka D
Franta Z
Mares M
Kopácek P
Source :
Biological chemistry [Biol Chem] 2006 Dec; Vol. 387 (12), pp. 1635-44.
Publication Year :
2006

Abstract

Two genes coding for cysteine peptidase inhibitors of the cystatin family (Om-cystatin 1 and 2) were isolated from a gut-specific cDNA library of the soft tick Ornithodoros moubata. Both cystatins were clearly down-regulated after a blood meal. Om-cystatin 1 is mainly expressed in the tick gut, while Om-cystatin 2 mRNA was also found in other tick tissues. Authentic Om-cystatin 2 was significantly more abundant than Om-cystatin 1 in the gut contents of fasting ticks and was associated with hemosome-derived residual bodies accumulated in the gut lumen. Om-cystatin 2 was also expressed by type 2 secretory cells in the salivary glands of unfed ticks. The inhibitory specificity of recombinant Om-cystatins 1 and 2 was tested with mammalian cysteine peptidases, as well as endogenous cysteine peptidases present in the tick gut. Both cystatins efficiently inhibited papain-like peptidases, including cathepsin B and H, but differed significantly in their affinity towards cathepsin C and failed to block asparaginyl endopeptidase. Our results suggest that the secreted cystatin isoinhibitors are involved in the regulation of multiple proteolytic targets in the tick digestive system and tick-host interaction.

Details

Language :
English
ISSN :
1431-6730
Volume :
387
Issue :
12
Database :
MEDLINE
Journal :
Biological chemistry
Publication Type :
Academic Journal
Accession number :
17132111
Full Text :
https://doi.org/10.1515/BC.2006.204