title: Molecular characterization of the C-3 DNA puff gene of Rhynchosciara americana.
abstract: We have mapped a region of about 33 kb which includes the transcription unit of the C-3 DNA puff gene of Rhynchosciara americana. The C-3 TU and a region extending approximately 800 bp upstream of the C-3 promoter were characterized. The TU is composed of three exons and produces a 1.1-kb mRNA whose level in salivary glands increases with the expansion of the C-3 puff. The C-3 messenger appears to undergo rapid deadenylation resulting in an RNA of about 0.95 kb which can still be observed in gland cells 15 h after the puff has regressed. The 1.1-kb mRNA codes for a 32.4-kDa, predominantly alpha-helical polypeptide with three conserved parallel coiled-coil stretches. The aa composition and structure of this polypeptide suggests that it is secreted and contributes to the formation of the cocoon in which the larvae pupate. The region upstream of the promoter contains several A-rich sequences with similarity to the ACS of yeast which might have a role in the initiation of replication/amplification.
authors.affiliation: Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, Brazil.
authors.forename: L O
authors.initials: LO
authors.lastname: Penalva
authors.forename: J
authors.initials: J
authors.lastname: Yokosawa
authors.forename: A J
authors.initials: AJ
authors.lastname: Stocker
authors.forename: M A
authors.initials: MA
authors.lastname: Soares
authors.forename: M
authors.initials: M
authors.lastname: Graessmann
authors.forename: T C
authors.initials: TC
authors.lastname: Orlando
authors.forename: C E
authors.initials: CE
authors.lastname: Winter
authors.forename: L M
authors.initials: LM
authors.lastname: Botella
authors.forename: A
authors.initials: A
authors.lastname: Graessmann
authors.forename: F J
authors.initials: FJ
authors.lastname: Lara
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D004175:Diptera / Q000235:genetics*; D017344:Genes, Insect; D019476:Insect Proteins; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D019476:Insect Proteins; D010446:Peptide Fragments; D012333:RNA, Messenger; C107553:Rap8 protein, Rhynchosciara americana; D012471:Salivary Proteins and Peptides