Fig. 1. Nucleotide and deduced amino-acid sequence of the DmCCAP gene. (A) Genomic sequence of DmCCAP. Sequences for the partial 5'-upstream region and for the cDNA are indicated in upper case, and the intervening sequences are presented in lower case. A consensus polyadenylation signal (AATAAA) is underlined, and the transcription initiation site is designated by a bold-faced letter. A putative arthropod initiator (TCATT) and a downstream promoter element (GTCG) are shaded gray. A putative signal peptide is indicated by italics; amino acids represent the predicted pre-pro-DmCCAP peptide. Potential endoproteolytic cleavage sites are designated by asterisks. (B) Schematic diagram of the genomic organization of DmCCAP. Open boxes represent exons and solid lines represent introns. Numbers indicate the nucleotide length for the corresponding exons and introns. Approximate positions for the start (ATG) and stop (TAA) codons are indicated by arrows. (C) Reconstruction of the pre-pro-DmCCAP structure. SP, signal peptide; CCAP-AP I, II, and III: CCAP-associated peptides I, II and III, respectively. CCAP and the other domains are represented by a shaded box and by open boxes, respectively. The number in each box indicates the amino acid length for each domain. The consensus endoproteolytic cleavage sites are also shown between the boxes. (D) Comparison of the amino acid sequences of CCAP precursors. Manduca sexta sequence from Loi et al. (Loi et al., 2001); mosquito (Anopheles gambiae) CCAP gene sequence was obtained from mosquito genome project database (agCG50022: accession no. EAA14174). Identical amino acids are highlighted in bold; there is a perfect match between sequences for the CCAP peptide (underlined). In addition, a significant homology was observed for the CCAP-AP III predicted peptide. Consensus proteolytic cleavage site between DmCCAP-AP II and III was not found in Manduca CCAP precursor structure. Surprisingly, the amidation signal (GRKR) was absent from the mosquito sequence, suggesting that CCAP in this insect may not be modified at its C terminus, resulting in much longer CCAP-like peptide. More careful characterization of the corresponding cDNA will be necessary to confirm this result.

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