A cDNA encoding a nuclear hormone receptor of the steroid/thyroid hormone-receptor superfamily from the human parasitic nematode Strongyloides stercoralis

A cDNA encoding a nuclear hormone receptor of the steroid thyroid receptor superfamily was obtained from third-stage larvae(L-3) of the parasitic roun dworm Strongyloides stercoralis. A recombinant clone was isolated via scree ning of an S. stercoralis cDNA library with a polymerase chain reaction (PC R)generated probe. The insert of 2583 bp contained the complete coding sequ ence of the receptor homologue. The conceptually translated amino acid sequ ence of this open reading frame encodes a 753-amino-acid-residue protein wi th an apparent molecular weight of 83.6 kDa and a predicted isoelectric poi nt (pI) of 8.52. The coding sequence is 69% AT and the noncoding sequence i s 72% AT, reflecting a characteristic A/T codon bias of S. stercoralis. In this report the amino acid sequence of the S. stercoralis nuclear hormone r eceptor of the steroid/thyroid receptor superfamily is compared with that o f nuclear hormones of Caenorhabditis elegans, human orphan nuclear receptor s, and insect ecdysone receptors. The potential role of steroids in the ind uction of hyperinfection syndrome is also discussed.