antigen processing and presentation of endogenous peptide antigen via MHC class Ib via ER pathway, TAP-dependent / tapasin binding / ABC-type peptide antigen transporter activity / ABC-type antigen peptide transporter / TAP complex / ABC-type peptide transporter activity / peptide antigen transport / MHC class Ib protein binding / cytosol to endoplasmic reticulum transport / TAP2 binding ...antigen processing and presentation of endogenous peptide antigen via MHC class Ib via ER pathway, TAP-dependent / tapasin binding / ABC-type peptide antigen transporter activity / ABC-type antigen peptide transporter / TAP complex / ABC-type peptide transporter activity / peptide antigen transport / MHC class Ib protein binding / cytosol to endoplasmic reticulum transport / TAP2 binding / TAP1 binding / peptide transport / peptide transmembrane transporter activity / antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway, TAP-dependent / MHC class I protein binding / endoplasmic reticulum-Golgi intermediate compartment membrane / T cell mediated cytotoxicity / Antigen Presentation: Folding, assembly and peptide loading of class I MHC / antigen processing and presentation of exogenous protein antigen via MHC class Ib, TAP-dependent / response to molecule of bacterial origin / defense response / MHC class I peptide loading complex / antigen processing and presentation of endogenous peptide antigen via MHC class I / ADP binding / positive regulation of T cell mediated cytotoxicity / transmembrane transport / peptide antigen binding / phagocytic vesicle membrane / centriolar satellite / protein transport / ER-Phagosome pathway / adaptive immune response / nuclear speck / endoplasmic reticulum membrane / endoplasmic reticulum / protein homodimerization activity / ATP hydrolysis activity / ATP binding / membrane / metal ion binding 類似検索 - 分子機能
Antigen peptide transporter 2 / ABC transporter Tap-like / Type 1 protein exporter / ABC transporter transmembrane region / ABC transporter type 1, transmembrane domain / ABC transporter integral membrane type-1 fused domain profile. / ABC transporter type 1, transmembrane domain superfamily / ABC transporter-like, conserved site / ABC transporters family signature. / ABC transporter ...Antigen peptide transporter 2 / ABC transporter Tap-like / Type 1 protein exporter / ABC transporter transmembrane region / ABC transporter type 1, transmembrane domain / ABC transporter integral membrane type-1 fused domain profile. / ABC transporter type 1, transmembrane domain superfamily / ABC transporter-like, conserved site / ABC transporters family signature. / ABC transporter / ABC transporter-like, ATP-binding domain / ATP-binding cassette, ABC transporter-type domain profile. / ATPases associated with a variety of cellular activities / AAA+ ATPase domain / P-loop containing nucleoside triphosphate hydrolase 類似検索 - ドメイン・相同性
ジャーナル: Immunity / 年: 2025 タイトル: Nucleotide-dependent conformational changes direct peptide export by the transporter associated with antigen processing. 著者: James Lee / Victor Manon / Jue Chen / 要旨: The transporter associated with antigen processing (TAP) delivers peptide antigens from the cytoplasm into the endoplasmic reticulum (ER) for loading onto major histocompatibility complex class I ...The transporter associated with antigen processing (TAP) delivers peptide antigens from the cytoplasm into the endoplasmic reticulum (ER) for loading onto major histocompatibility complex class I (MHC-I) molecules. To examine the mechanisms of peptide transport and release into the ER, we determined cryo-electron microscopy structures of the human TAP heterodimer in multiple functional states along the transport cycle. In the inward-facing conformation, when the peptide translocation cavity within the TAP heterodimer is exposed to the cytosol, ATP binding strengthened intradomain assembly. Transition to the outward-facing conformation, when the transporter opens to the ER lumen, led to a complete reconfiguration of the peptide-binding site, facilitating peptide release. ATP hydrolysis opened the catalytically active nucleotide-binding consensus site, and the subsequent separation of the nucleotide-binding domains reset the transport cycle. These findings establish a comprehensive structural framework for understanding unilateral peptide transport, vanadate trapping, and trans-inhibition-an internal feedback mechanism that prevents excessive peptide accumulation and activation of the ER stress response.