CDNA cloning and analysis of alanine-rich cuticle protein gene of common fouling barnacle, Balanus amphitrite

Abstract

Article history: Received on: 16/03/2015 Revised on: 31/03/2015 Accepted on: 22/04/2015 Available online: 20/05/2015 Hard cuticle of insects is a complex structure composed mainly of several proteins and chitin fibers. Cuticular proteins are important as presence of different cuticular proteins confer different mechanical properties to the exoskeletons of insects. Hence, there is growing interest in studying cuticular proteins as bioengineering of these proteins may help in synthesis of biomaterials for various applications. Till date many cuticle proteins have been identified from insects. These proteins show presence of characteristic motifs in them such as R&R motif, extended R&R motif, AAP (V/L) motif etc. We have identified one of such putative cuticle protein encoding gene from common fouling barnacle, Balanus amphitrite by cDNA cloning and sequencing. The gene was found to encode an open reading frame (ORF) of 102 amino acids. The deduced protein sequence was found rich in alanine forming almost 22% of the total amino acids. Other two predominant amino acids, valine and proline together contributed ~23% of total amino acids. The hydropathy plot of the amino acid sequence showed presence of two hydrophobic regions surrounding central hydrophilic region. The protein sequence showed presence of three characteristic YHAAP (V/L) motifs at the C-terminus.