Fig. 1.

Nucleotide and deduced amino acid sequences of Homarus americanus prepro-calcitonin-like diuretic hormone (Homam-CLDH). (A) Nucleotide sequence of Homam-prepro-CLDH (accession no. GQ290461). The open reading frame of the cDNA, including the stop codon, is shown in bold font, with the two 3′ polyadenylation signal sequences indicated by underline in black. The two primers used for RT-PCR tissue profiling are underlined in green. (B) Deduced amino acid sequence of Homam-prepro-CLDH. The signal peptide is shown in gray, with prohormone convertase cleavage loci shown in black. The encoded CLDH isoform is shown in red, with additional precursor-related peptides shown in blue. The asterisk indicates the position of the stop codon. (C) Putative processing scheme resulting in the production of Homam-CLDH from its precursor protein. The first line of sequence shows the full-length prepro-hormone with the cleavage locus for signal peptidase underlined. The second line of sequence shows the cleaved pro-hormone with the loci for prohormone convertase underlined. The third line of sequence shows the immature CLDH peptide with the site of action for carboxypeptidase underlined. The fourth line of sequence shows the peptide resulting from carboxypeptidase activity with the Gly destined for α-amidation underlined. The final line of sequence shows the putative, mature CLDH after full post-translational processing.