title: Mechanistic basis of pre-T cell receptor-mediated autonomous signaling critical for thymocyte development.
abstract: The pre-T cell receptor (TCR) is crucial for early T cell development and is proposed to function in a ligand-independent way. However, the molecular mechanism underlying the autonomous signals remains elusive. Here we show that the pre-TCR complex spontaneously formed oligomers. Specific charged residues in the extracellular domain of the pre-TCR alpha-chain mediated formation of the oligomers in vitro. Alteration of these residues eliminated the ability of the pre-TCR alpha-chain to support pre-TCR signaling in vivo. Dimerization but not raft localization of CD3epsilon was sufficient to simulate pre-TCR function and promote beta-selection. These results suggest that the pre-TCR complex can deliver its signal autonomously through oligomerization of the pre-TCR alpha-chain mediated by charged residues.
authors.affiliation: Laboratory for Cell Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Yamasaki
authors.forename: Eri
authors.initials: E
authors.lastname: Ishikawa
authors.forename: Machie
authors.initials: M
authors.lastname: Sakuma
authors.forename: Koji
authors.initials: K
authors.lastname: Ogata
authors.forename: Kumiko
authors.initials: K
authors.lastname: Sakata-Sogawa
authors.forename: Michio
authors.initials: M
authors.lastname: Hiroshima
authors.forename: David L
authors.initials: DL
authors.lastname: Wiest
authors.forename: Makio
authors.initials: M
authors.lastname: Tokunaga
authors.forename: Takashi
authors.initials: T
authors.lastname: Saito
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology*
chemical_list: D008562:Membrane Glycoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; C090377:pre-T cell receptor alpha