A family of putative metalloproteases in the salivary glands of the tick Ixodes ricinus

Abstract

Ticks are obligate blood‐feeding arachnids. During their long‐lasting blood meal, they have to counteract the protective barriers and defense mechanisms of their host. These include tissue integrity, pain, hemostasis, and the inflammatory and immune reactions. Here, we describe a multigene family coding for five putative salivary metalloproteases induced during the blood meal of Ixodes ricinus. The evolutionary divergence inside the family was driven by positive Darwinian selection. This came together with individual variation of expression, functional heterogeneity, and antigenic diversification. Inhibition of the expression of some of these genes by RNA interference prevented completion of the tick blood meal and affected the ability of the tick saliva to interfere with host fibrinolysis. This family of proteins could therefore participate in the inhibition of wound healing after the tick bite, thereby facilitating the completion of the blood meal.

The secreted salivary proteome of the pea aphid Acyrthosiphon pisum characterised by mass spectrometry

“…Peptides matching to four loci on the pea aphid genome and a single EST (APG01291) demonstrated homology to this family of proteins. M1 metalloproteases cleave singleamino acids from the N terminus of small peptides and secreted metalloproteases have been identified in the salivary glands of Anopheles mosquito and the tick Ixodes ricinus [38,39], and in the saliva of the tick I. scapularis [40]. To date, proteases have not been demonstrated in aphid saliva using substrate-specific assays or zymography [16].…”

Immunoprotective potential of a Rhipicephalus (Boophilus) microplus metalloprotease

“…Metzincin MPs members have been found to participate in tissue development, maintenance, remodeling, and in unspecific protein degradation of intake proteins (Gomis-Ruth, 2009;Rivera et al, 2010). MPs have been identified in various tick species, and are considered crucial for maintenance of blood meal related functions (Francischetti et al, 2003;Harnnoi et al, 2007;Decrem et al, 2008a;Barnard et al, 2012). The up-regulation of MPs transcription in salivary glands has been correlated with tick blood feeding (Francischetti et al, 2003;Harnnoi et al, 2007;Decrem et al, 2008aDecrem et al, , 2008bBarnard et al, 2012;Adamson et al, 2013).…”

“…MPs have been identified in various tick species, and are considered crucial for maintenance of blood meal related functions (Francischetti et al, 2003;Harnnoi et al, 2007;Decrem et al, 2008a;Barnard et al, 2012). The up-regulation of MPs transcription in salivary glands has been correlated with tick blood feeding (Francischetti et al, 2003;Harnnoi et al, 2007;Decrem et al, 2008aDecrem et al, , 2008bBarnard et al, 2012;Adamson et al, 2013). In Ixodes scapularis, MPs are secreted in saliva, playing an essential role in fibrin and fibrinogen breakdown (Francischetti et al, 2003).…”

Inhibition of Neutrophil Function by Two Tick Salivary Proteins

“…Disintegrins bind to integrins and interfere with ligand binding, probably through competitive inhibition; the cysteine-rich domain of ADAM/ADAMTS serves to target the molecule to the substrates and facilitates enzymatic functions (53). Disintegrins in tick saliva inhibit platelet aggregation and are important for successful tick feeding (8,11,16). ISL 929 and ISL 1373 belong to the ixostatin family and have been proposed to be involved in angiogenesis and repair inhibition (44).…”