title: The assembly of CD1e is controlled by an N-terminal propeptide which is processed in endosomal compartments.
abstract: CD1e displays unique features in comparison with other CD1 proteins. CD1e accumulates in Golgi compartments of immature dendritic cells and is transported directly to lysosomes, where it is cleaved into a soluble form. In these latter compartments, CD1e participates in the processing of glycolipid antigens. In the present study, we show that the N-terminal end of the membrane-associated molecule begins at amino acid 20, whereas the soluble molecule consists of amino acids 32-333. Thus immature CD1e includes an N-terminal propeptide which is cleaved in acidic compartments and so is absent from its mature endosomal form. Mutagenesis experiments demonstrated that the propeptide controls the assembly of the CD1e alpha-chain with beta(2)-microglobulin, whereas propeptide-deleted CD1e molecules are immunologically active. Comparison of CD1e cDNAs from different mammalian species indicates that the CD1e propeptide is conserved during evolution, suggesting that it may also optimize the generation of CD1e molecules in other species.
authors.affiliation: INSERM, U.725 Biology of Human Dendritic Cells, Strasbourg, , France.
authors.forename: Blandine
authors.initials: B
authors.lastname: Maître
authors.forename: Catherine
authors.initials: C
authors.lastname: Angénieux
authors.forename: Virginie
authors.initials: V
authors.lastname: Wurtz
authors.forename: Emilie
authors.initials: E
authors.lastname: Layre
authors.forename: Martine
authors.initials: M
authors.lastname: Gilleron
authors.forename: Anthony
authors.initials: A
authors.lastname: Collmann
authors.forename: Sabrina
authors.initials: S
authors.lastname: Mariotti
authors.forename: Lucia
authors.initials: L
authors.lastname: Mori
authors.forename: Dominique
authors.initials: D
authors.lastname: Fricker
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Cazenave
authors.forename: Alain
authors.initials: A
authors.lastname: van Dorsselaer
authors.forename: Christian
authors.initials: C
authors.lastname: Gachet
authors.forename: Gennaro
authors.initials: G
authors.lastname: de Libero
authors.forename: Germain
authors.initials: G
authors.lastname: Puzo
authors.forename: Daniel
authors.initials: D
authors.lastname: Hanau
authors.forename: Henri
authors.initials: H
authors.lastname: de la Salle
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids; D000818:Animals; D018949:Antigens, CD1 / Q000737:chemistry / Q000378:metabolism*; D002451:Cell Compartmentation; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004330:Drosophila; D004721:Endoplasmic Reticulum / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals; D012995:Solubility
chemical_list: D000596:Amino Acids; D018949:Antigens, CD1; C417738:CD1e antigen; D050505:Mutant Proteins; D010455:Peptides; D021382:Protein Sorting Signals