RRC ID 35978
著者 Konogami T, Yang Y, Ogihara MH, Hikiba J, Kataoka H, Saito K.
タイトル Ligand-dependent responses of the silkworm prothoracicotropic hormone receptor, Torso, are maintained by unusual intermolecular disulfide bridges in the transmembrane region.
ジャーナル Sci Rep
Abstract The insect membrane-protein, Torso, is a member of the receptor-tyrosine-kinase family, and is activated by its ligand, prothoracicotropic hormone (PTTH). Although PTTH is one of the most important regulators of insect development, the mechanism of Torso activation by the hormone has remained elusive. In this study, using heterologous expression in cultured Drosophila S2 cells, we detected ligand-independent dimerization of silkworm Torso, and found that the receptor molecules in the dimer were linked by intermolecular disulfide bridges. By examining the oligomerization states of several truncation and substitution mutants of Torso, atypical cysteine residues in the transmembrane region were identified as being responsible for the intermolecular linkage in the dimer. The replacement of all of the cysteines in the region with phenylalanines abolished the disulfide-bond-mediated dimerization; however, non-covalent dimerization of the mutant was detected using a cross-linking reagent, both with and without ligand stimulation. This non-covalent dimerization caused apparent receptor autophosphorylation independently of the ligand stimulation, but did not promote the ERK phosphorylation in the downstream signaling pathway. The unique Torso structure with the intermolecular disulfide bridges in the transmembrane region is necessary to maintain the ligand-dependent receptor functions of autophosphorylation and downstream activation.
巻・号 6
ページ 22437
公開日 2016-3-1
DOI 10.1038/srep22437
PII srep22437
PMID 26928300
PMC PMC4772477
MeSH Animals Bombyx Cell Line Cysteine / chemistry Dimerization Disulfides / chemistry* Drosophila Insect Hormones Insect Proteins / metabolism* Phosphorylation Protein Binding Protein Structure, Tertiary Receptor Protein-Tyrosine Kinases / metabolism*
IF 3.998
引用数 3
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
カイコ p50