CPF and CPFL, two related gene families encoding cuticular proteins of Anopheles gambiae and other insects

• Published in: Insect biochemistry and molecular biology 2007-07, Vol.37 (7), p.675-688
• Main Authors: Togawa, Toru, Augustine Dunn, W., Emmons, Aaron C., Willis, Judith H.
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs; Amino Acid Sequence; amino acid sequences; Animals; Anopheles - chemistry; Anopheles - genetics; Anopheles gambiae; Arthropoda; binding properties; Chitin - metabolism; Chitin-binding; Cloning, Molecular; consensus sequence; conserved sequences; Cuticle; Databases, Protein; developmental stages; DNA Primers; gene expression; Genes, Insect; insect cuticle; insect proteins; Insect Proteins - chemistry; Insect Proteins - metabolism; Insecta - chemistry; Insecta - genetics; Larva - chemistry; Larva - genetics; Molting - genetics; multigene family; nucleotide sequences; Phylogeny; Protein motifs; Pupa - chemistry; Pupa - genetics; R&R Consensus; Real-time qRT-PCR; recombinant fusion proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA - isolation & purification; Sequence Analysis; sequence homology; Sequence Homology, Amino Acid; Species Specificity; Tenebrio - chemistry; Tenebrio - genetics; Tenebrio molitor
• ISSN: 0965-1748; 1879-0240
• DOI: 10.1016/j.ibmb.2007.03.011

Cuticular proteins (CPs) are structural proteins of insects as well as other arthropods. Several CP families have been described, among them a small family defined by a 51 amino acid motif [Andersen, S.O., Rafn, K., Roepstorff, P., 1997. Sequence studies of proteins from larval and pupal cuticle of the yellow meal worm, Tenebrio molitor. Insect Biochem. Mol. Biol. 27, 121–131]. We identified four proteins of this family in Anopheles gambiae that we have named CPF. We have also identified CPFs from other insects by searching databases. Alignment of these CPF proteins showed that the conserved region is only 44 aa long and revealed another conserved motif at the C-terminus. A dendrogram divided the CPF proteins into four groups, one basal and three specialized. We also identified several proteins of another CP family, CPFL, which has similarities to CPFs. CPFs and CPFLs share some protein motifs. Expression studies with real-time qRT-PCR of the A. gambiae CPFs and CPFLs showed that the four CPFs and one CPFL gene are expressed just before pupal or adult ecdysis, suggesting that they are components of the outer layer of pupal and adult cuticles. The other CPFLs appear to contribute to larval cuticle. Recombinant CPF proteins did not bind to chitin in the assay we used.