Identification of novel 70-kDa heat shock protein-encoding cDNAs from Schistosoma japonicum

A diverse range of organisms respond to a variety of chemical, physiologica l and temperature-associated stresses by a rapid and transient increase in the synthesis of heat shock proteins. We immunoscreened a Uni-ZAP XR cDNA l ibrary, prepared from mRNA isolated from the Philippine strain of the Asian bloodfluke. Schistosoma japonicum, using hyperimmune rabbit sera raised ag ainst soluble adult S. japonicum proteins. Six 70-kDa heat shock protein-en coding cDNA clones were identified which, upon further analysis, were separ ated into two distinct protein groups within the 70-kDa heat shock protein family, the 70-kDa heat shock proteins and the immunoglobulin heavy chain-b inding proteins/glucose-related proteins (Grp78). A representative from bot h groups was fully sequenced and compared with homologous sequences availab le in the GenBank/EMBL database as the first stage in determining the role of their expression products in the regulation of S. japonicum development, in the induction of immunity, and whether they act as molecular chaperones capable of modulating the correct folding or repair of proteins within thi s species of schistosome. (C) 1999 Australian Society for Parasitology. Pub lished by Elsevier Science Ltd. All rights reserved.