Molecular cloning and expression profiles of calreticulin gene from the diamondback moth, Plutella xylostella

Abstract

Calreticulin (CRT) plays pivotal roles in Ca2+ homeostasis, molecular chaperoning, infection, inflammation and innate immunity. In an attempt to study the involvement of CRT in innate immunity, the full‐length cDNA of calreticulin (PxCRT) was cloned from the diamondback moth, Plutella xylostella. It consists of 1674 bp (excluding poly‐A tail) with a longest open reading frame (ORF) of 1197 bp encoding 398 amino acids. In silico analysis of PxCRT ORF reveals that it has various repeat motifs and endoplasmic reticulum retention signal found in all the calreticulin proteins. As expected, high amino acid sequence identities were found from other CRTs identified from Bombyx mori (87%), Galleria mellonella (87%), Apis mellifera (74%), Anopheles gambiae (74%), Tribolium castaneum (73%), Culex quinquefasciatus (73%), Rhodnius prolixus (72%), Nasonia vitripennis (71%), Drosophila melanogaster (71%) and Haemaphysalis qinghaiensis (68%). During development, P. xylostella expressed PxCRT predominantly in the pupal stage. In addition, spatial expression pattern analysis indicates that PxCRT was highly expressed in the silk gland. PxCRT mRNA, furthermore, was strongly induced 3 to 6 h after laminarin treatment, suggesting that PxCRT appears to be involved in immune responses and also plays an important role in the silk gland.

Two calcium‐binding chaperones from the fat body of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) involved in diapause

“…Notably, this variation is common to other insect CrTs (R. J. Kim et al, 2010;L. Wang et al, 2012) and ticks (Ferreira et al, 2002).…”

“…The P‐arm domain is a typical proline‐rich region forming an extended, flexible arm including a nuclear localization signal (Gao et al, 2008), ERp57‐binding region (Martin et al, 2006), and three CrT family repeat A/B signature motifs (Michalak et al, 2009). The LdCrT putative nuclear localization signal was identical to that in MsCrT and Plutella xylostella CrT (R. J. Kim et al, 2010), while it had minor variations from that in DmCrT. Erp57 is an oxidoreductase from the family of protein disulfide isomerases involved in protein folding in the ER lumen, and interacts with CrT (Oliver et al, 1999).…”

“…The LdCrT putative nuclear localization signal was identical to that in MsCrT and Plutella xylostella CrT (R. J. Kim et al, 2010), while it had minor variations from that in DmCrT. Erp57 is an oxidoreductase from the family of protein disulfide isomerases involved in protein folding in the ER lumen, and interacts with CrT (Oliver et al, 1999).…”

“…LdCrT, were all predicted to possess a signal peptide (Choi et al, 2002;Goo et al, 2005; R. J. Kim et al, 2010;L. Wang et al, 2012).…”

“…CrT mRNA was also reported to be almost undetectable in the fat body, while it was prominent in the midgut and Malpighian tubules, and the highest in the silk gland in P. xylostella larvae; however, this analysis was based on a semiquantitative reverse-transcriptase PCR method (R. J. Kim et al, 2010), which can be less sensitive.…”