A clip domain serine protease (cSP) from the Chinese mitten crab Eriocheir sinensis: cDNA characterization and mRNA expression

Three clip domain serine proteases (cSPs) and one clip domain serine protease homologue (cSPH) identified from haemocytes and eyestalk cDNA libraries of swimming crab Portunus trituberculatus

“…They are consistent with the known crustacean clip domain serine proteases or PPAFs [8,21,22]. Unlike commonly encountered substitution of S (Ser) to G (Gly) at the third catalytic site, the second catalytic site D (Asp) is replaced by amino acid A (Ala) for PtcSPH.…”

“…For example, FcSPH was mainly distributed in heart, gill, stomach, intestine and its expression level was lower in haemocytes and hepatopancreas [12]. EscSP mRNA expression was highest in muscle [8]. PtSPH is strongly expressed in eyestalk [9].…”

“…Another masquerade-like serine protease homologue found in P. monodon is proved to be a multifunctional immune molecule in shrimp defence [14]. One cSP identified in Eriocheir sinensis and one cSPH identified in Scylla paramamosain are supposed to function as an innate immune recognition molecule and play a key role in crab immunity [3,8]. All these results suggest that cSPs or cSP homologues are related to antibacterial or immune regulation.…”

“…Thereafter, more studies on crustacean clip-SPs (or clip SP homologues) have been carried out. In contrary to the broad participation of other SPs in diverse biological processes, the cSPs in arthropod are reported to be only involved in the development and immunity [8]. For example, cSPs from Portunus trituberculatus [9], Penaeus monodon [10,11], Fenneropenaeus chinensis [12] and Fenneropenaeus indicus [13] are reported to play significant roles in innate immunity.…”

Molecular cloning, characterization and expression analysis of two apoptosis genes, caspase and nm23, involved in the antibacterial response in Chinese mitten crab, Eriocheir sinensis

“…However, in E. sinensis, the temporal response of immune-related gene expression is both gene-and bacteriadependent. The pathogen L. anguillarum, elicited two peaks in EscSP expression at 2 h and 12 h post-injection (4.96 and 9.90 fold, respectively) [57], the other hand, V. anguillarum induced three EsproPO peaks at 2 h (3.68 fold), 12 h (32.1 fold), and 48 h (18.6 fold) post-injection [58]. The collective results indicate that E. sinensis caspase and nm23 are constitutive and inducible acute-phase proteins involved in defense response against bacterial infection.…”