Multienzyme degradation of host serum albumin in ticks
| Autor: | Petr Kopáček, Jan Perner, Martin Horn, Jitka Konvičková, Daniel Sojka, Jana Pytelková, Jana Schrenková, Michael Mareš |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Aspartic Acid Proteases Proteolysis 030231 tropical medicine Serum albumin Microbiology Hemoglobins 03 medical and health sciences 0302 clinical medicine Cysteine Proteases medicine Animals Serum Albumin Whole blood chemistry.chemical_classification Ixodes medicine.diagnostic_test biology Gene Expression Profiling Albumin Hydrogen-Ion Concentration Exopeptidase Blood proteins Amino acid 030104 developmental biology Infectious Diseases chemistry Biochemistry Insect Science biology.protein Female Parasitology Hemoglobin |
| Zdroj: | Ticks and Tick-borne Diseases. 7:604-613 |
| ISSN: | 1877-959X |
| DOI: | 10.1016/j.ttbdis.2015.12.014 |
| Popis: | Host blood proteins, represented mainly by hemoglobin and serum albumin, serve as the ultimate source of amino acids needed for de novo protein synthesis during tick development and reproduction. While uptake and processing of hemoglobin by tick gut cells have been studied in detail, molecular mechanisms of host serum albumin degradation remain unknown. In this work, we have used artificial membrane feeding of Ixodes ricinus females on a hemoglobin-free diet in order to characterize the proteolytic machinery involved in albuminolysis. Morphological comparisons of ticks fed on whole blood (BF) and serum (SF) at microscopic and ultrastructural levels showed that albumin and hemoglobin have different trafficking routes in tick gut cells. Analysis in vitro with selective inhibitors demonstrated that albumin is degraded at an acidic pH by a network of cysteine and aspartic peptidases with predominant involvement of cysteine cathepsins having endo- and exopeptidase activities. The cleavage map of albumin and the roles of individual peptidases in albumin degradation were determined. These results indicate that the albuminolytic pathway is controlled by the same proteolytic system that is responsible for hemoglobinolysis. This was further supported by the overall similarity of gut peptidase profiles in SF and BF ticks at the transcriptional and enzymatic activity levels. In conclusion, our work provides evidence that although hemoglobin and albumin are transported differentially during heterophagy they are digested by a common multienzyme proteolytic network. This central digestive system, critical for successful blood feeding in tick females, thus represents a valuable target for novel anti-tick interventions. |
| Databáze: | OpenAIRE |
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