title: Insect prothoracicotropic hormone: a new member of the vertebrate growth factor superfamily.
abstract: Prothoracicotropic hormone (PTTH) is a brain neurosecretory protein that controls insect development. PTTH of the silkmoth Bombyx mori is a homodimeric protein, the subunit of which consists of 109 amino acids. Clear-cut sequence similarity to any other proteins has not been observed. By disulfide-bond pattern analysis and modeling of the PTTH structure based on the known three-dimensional (3D) structures of growth factor family with cystine-knot motif, we propose that the PTTH protomer adopts the fold unique to the structural superfamily of the growth factors, beta-nerve growth factor (beta-NGF), transforming growth factor-beta 2 (TGF-beta 2), and platelet-derived growth factor-BB (PDGF-BB). The insect neurohormone PTTH appears to be a member of the growth factor superfamily, sharing a common ancestral gene with the three vertebrate growth factors, beta-NGF, TGF-beta 2 and PDGF-BB.
mesh_terms: D000595:Amino Acid Sequence; D004220:Disulfides; D006133:Growth Substances / Q000737:chemistry*; D007301:Insect Hormones / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000737:chemistry; D009479:Neuropeptides / Q000737:chemistry*; D010982:Platelet-Derived Growth Factor / Q000235:genetics; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D016212:Transforming Growth Factor beta / Q000235:genetics
chemical_list: D004220:Disulfides; D006133:Growth Substances; D007301:Insect Hormones; D009414:Nerve Growth Factors; D009479:Neuropeptides; D010982:Platelet-Derived Growth Factor; D016212:Transforming Growth Factor beta; C009089:prothoracicotropic hormone