Amblyomma americanum tick saliva insulin‐like growth factor binding protein‐related protein 1 binds insulin but not insulin‐like growth factors. Issue 5 (25th June 2015)

• Record Type: Journal Article
• Authors: Radulović, Ž. M.; Porter, L. M.; Kim, T. K.; Bakshi, M.; Mulenga, A.
• Is Part Of: Insect molecular biology. Volume 24:Issue 5(2015:Oct.)
• Page Start: 539
• Page End: 550
• Publication Date: 2015-06-25
• Subjects: Insects -- Molecular aspects -- Periodicals; 595.7
• DOI: 10.1111/imb.12180
• Languages: English
• ISSNs: 0962-1075

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>Silencing <italic>Amblyomma americanum</italic> insulin‐like growth factor binding protein‐related protein 1 (<italic>Aam</italic>IGFBP‐rP1) mRNA prevented ticks from feeding to repletion. In this study, we used recombinant (r)<italic>Aam</italic>IGFBP‐rP1 in a series of assays to obtain further insight into the role(s) of this protein in tick feeding regulation. Our results suggest that <italic>Aam</italic>IGFBP‐1 is an antigenic protein that is apparently exclusively expressed in salivary glands. We found that both males and females secrete <italic>Aam</italic>IGFBP‐rP1 into the host during feeding and confirmed that female ticks secrete this protein from within 24–48 h after attachment. Our data suggest that native <italic>Aam</italic>IGFBP‐rP1 is a functional insulin binding protein in that both yeast‐ and insect cell‐expressed r<italic>Aam</italic>IGFBP‐rP1 bound insulin, but not insulin‐like growth factors. When subjected to anti‐blood clotting and platelet aggregation assays, r<italic>Aam</italic>IGFBP‐rP1 did not have any effect. Unlike human IGFBP‐rP1, which is controlled by trypsinization, r<italic>Aam</italic>IGFBP‐rP1 is resistant to digestion, suggesting that the tick protein may not be under mammalian host control at the tick feeding site. The majority of tick‐borne pathogens are transmitted 48 h after the tick has attached. Thus, the demonstrated antigenicity and secretion into the host within 24–48 h of the tick starting to feed makes <italic>Aam</italic>IGFBP‐rP1 an attractive target for antitick vaccine development.</p> </abstract>