The DNA puff BhB10-1 gene encodes a glycine-rich protein secreted by the late stage larval salivary glands of Bradysia hygida

• Published in: Gene Vol. 231; no. 1; pp. 67 - 75
• Main Authors: Fontes, A.M., Conacci, M.E., Monesi, N., de Almeida, J.C., Paçó-Larson, M.L.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 29-04-1999
• Subjects: Amino Acid Sequence; amino acid sequences; amplification; animal proteins; Animals; Base Sequence; Bradysia hygida; complementary DNA; Diptera; DNA; DNA, Complementary; genbank/l43853; genbank/l43904; Gene amplification; gene expression; Genes, Insect; genetic regulation; Glycine - analysis; Glycine-rich protein; Insect Proteins; Insecta - embryology; Insecta - genetics; introns; Larva - metabolism; larvae; messenger RNA; Molecular Sequence Data; nucleotide sequences; polypeptides; protein secretion; Salivary gland; salivary glands; Salivary Glands - embryology; Salivary Glands - metabolism; Salivary Proteins and Peptides - chemistry; Salivary Proteins and Peptides - genetics; Salivary Proteins and Peptides - metabolism; Sciaridae; structural genes; Transcription, Genetic; Gene amplification; BhB10-1, BhC4-1, B. hygida DNA puff B10 and C4 genes; BhB10-1 and BhC4-1, proteins coded by BhB10-1 and BhC4-1 genes; Salivary gland; Sciaridae; MBP, maltose binding protein; MBP–BhB10-1, maltose binding protein fused to BhB10-1 protein; 3′ UTR, 3′ untranslated region; Diptera; Glycine-rich protein; Anti-BhB10-1, a polyclonal antibody specific for the BhB10-1 protein
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/S0378-1119(99)00089-X

We present the molecular characterization of a gene of
Bradysia hygida DNA puff B10 whose temporal expression in the salivary gland correlates with the puff expansion. The transcription unit of this gene, named
BhB10-1, was mapped in a 2-kb
EcoRI genomic fragment that is amplified in the salivary gland of late fourth instar larvae. Its 1.3-kb transcript undergoes poly-A tail shortening during development, indicating that post-transcriptional controls as well as transcription activation are involved in the temporal regulation of the
BhB10-1 gene. Analysis of the deduced amino acid sequence from the cDNA indicates that the BhB10-1 protein is a glycine-rich secretory protein. A BhB10-1-fusion protein expressed in bacteria was used to raise polyclonal antibodies. Using an immunopurified antibody, we identified the product of the DNA puff
BhB10-1 gene as a 23-kDa polypeptide that is produced mainly by the salivary gland regions S1 and S3 and is present in the saliva of late larvae. This is the first direct identification of a protein encoded by a DNA puff amplified gene.