ES proteins analysis of Angiostrongylus cantonensis: products of the potential parasitism genes?

Abstract

The expressed sequence tags (ESTs) of Angiostrongylus cantonensis were analyzed in an attempt to gain further insight into its genomic expression patterns. A total of 1,277 ESTs of A. cantonensis were randomly downloaded from NCBI databank. ESTs were analyzed and annotated using Blastx. The result showed that there were 60 ESTs had no match to any of the proteins and gene sequences in the published databases, and 695 ESTs score more than 80. According to the function, the identified 695 ESTs could be grouped into 13 categories related to metabolism, cellular development, immune evasion, host-parasite interactions, and so on. Among them, 65 (9.4%) were proteases and protease inhibitors, represented 19 potential proteases and protease inhibitors genes; 42 (6.0%) were allergens or antigens, represented 15 potential antigens/allergens genes. Signal P analysis was applied to the 19 putative proteases and protease inhibitors and the 15 antigens/allergens protein sequences to identify the potential signal peptides and anchors. The result demonstrated that there were ten putative proteins had N-terminal signal peptides and three had signal anchors, these putative excretory/secretory proteins might be the products of potential parasitism genes which played an important role in the adaptation of A. cantonensis to a parasitism life. These parasitism genes and proteins identified are expected to become potential targets for future research on anti-A. cantonensis drugs; moreover, the resulting genetic information is useful in elucidating the mechanisms of parasitism of A. cantonensis.

Immunolocalization and developmental expression patterns of two cathepsin B proteases (AC-cathB-1, -2) of Angiostrongylus cantonensis

“…Obviously, consistent with the infective stage of L3 is an intense staining of AC-cathBs in the esophagus and excretory. So, the results in this report further supported our previous observations resulting from Signal-P, RT-PCR, and western blot analyses (Fang et al, 2010;Ni et al, 2012), and from electrospray ionization mass spectrometry (Morassutti et al, 2012). There is a big difference in the structure between larvae and adults, no lateral glands and lateral alae could be seen in the body wall of adult A. cantonensis, while they were more obvious in L1 and L3 (Xu et al, 1989;Ding et al, 1990).…”

“…Haematophagous nematodes express proteases of different mechanistic classes in their intestines, many of which have proven or putative roles in degradation of haemoglobin and other proteins involved in nutrition, however, most of the proteases described previously are expressed in the intestine and many of them do not appear in excretory/ secretory (ES) products, implying that they act locally in the intestine (Williamson et al, 2003). The ES products and the characterization of cathepsin B protease in different stages of development in Angiostrongylus cantonensis has been described using Signal-P (Fang et al, 2010), RT-PCR, and western blot analyses (Ni et al, 2012), however, there are no data that directly support the cathepsin B protease (AC-cathB-1, -2) were released by the parasite as ES products and the anatomic location of the proteases in A. cantonensis remains unclear. Here we look at the anatomical localization and expression characterization of two cysteine proteases (ACcathB-1, -2) in order to assist us in understanding better the role of cathepsin B in the A. cantonensis.…”

Human Angiostrongylus cantonensis: an update

“…In addition, a total of 1,277 expressed sequence tags (ESTs) of A. cantonensis were randomly downloaded from NCBI and analyzed. According to function, the identified 695 ESTs could be grouped into 13 categories [11]. In addition, some proteins such as cystatin [12], galectin [13], and γ-butyrobetaine hydroxylase [14] of A. cantonensis have been cloned and expressed, and their functions have been assayed.…”

Angiostrongylus cantonensis in China

“…According to the function, the identified 695 ESTs could be grouped into 13 categories related to metabolism, cellular development, immune evasion, host-parasite interactions, and so on. Among them, 65 (9.4 %) were proteases and protease inhibitors, represented 19 potential proteases and protease inhibitors genes; 42 (6.0 %) were allergens or antigens, represented 15 potential antigens/allergens genes (Fang et al 2010). It is also excepted that the whole genome of A. cantonensis is sequencing by Sun Yat-sen University.…”