Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Jun;7(4):604-13.
doi: 10.1016/j.ttbdis.2015.12.014. Epub 2015 Dec 19.

Multienzyme degradation of host serum albumin in ticks

Daniel Sojka  1 , Jana Pytelková  2 , Jan Perner  3 , Martin Horn  2 , Jitka Konvičková  3 , Jana Schrenková  3 , Michael Mareš  2 , Petr Kopáček  4
Affiliations

Multienzyme degradation of host serum albumin in ticks

Daniel Sojka et al. Ticks Tick Borne Dis. 2016 Jun.

Abstract

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.

Keywords: Albumin digestion; Gut; Proteolysis; Tick.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

LinkOut - more resources