Molecular cloning and localization of a cDNA encoding a crustacean hyperglycemic hormone from the South African spiny lobster, Jasus lalandii.

摘要

A cDNA, encoding a crustacean hyperglycemic hormone (cHH) of the South African spiny lobster, Jasus lalandii has been cloned. The cDNA consists of 1773bp with an open reading frame of 399bp that encodes a preprohormone of 133 amino acid residues. The preprohormone consists of a 25 amino acid hydrophobic signal peptide, a 32 amino acid cHH precursor-related peptide (CPRP) and the cHH sequence of 72 amino acid residues. The cHH sequence is flanked N-terminally by a Lys-Arg cleavage site and C-terminally by Gly-Lys, where Gly serves as an amidation site. The deduced amino acid sequence of the CPRP is in complete agreement with a peptide previously elucidated from sinus glands of J. lalandii, code-named CPRP 2 and the sequence of the cHH peptide matches that of the minor cHH isoform of J. lalandii, i.e. crustacean hyperglycemic hormone-II (cHH-II), which was also previously obtained by peptide sequencing. In situ hybridization on eyestalks revealed strong cHH-II mRNA expression in a subset of neurosecretory cells of the X-organ.