Interaction of TAPBPR, a tapasin homolog, with MHC-I molecules promotes peptide editing [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 636.0897 Animal husbandry
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2016
• Mô tả vật lý: Size: p. E1006-E1015 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 260942
• Chủ đề: 1. 60 applied life sciences; 2. Antigen presentation; 3. Major histocompatibility complex; 4. Peptide loading; 5. Protein interactions; 6. Saxs

Tóm tắt

 Peptide loading of major histocompatibility complex class I (MHC-I) molecules is central to antigen presentation, self-tolerance, and CD8<
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  T-cell activation. TAP binding protein, related (TAPBPR), a widely expressed tapasin homolog, is not part of the classical MHC-I peptide-loading complex (PLC). Using recombinant MHC-I molecules, we show that TAPBPR binds HLA-A*02:01 and several other MHC-I molecules that are either peptide-free or loaded with low-affinity peptides. Fluorescence polarization experiments establish that TAPBPR augments peptide binding by MHC-I. The TAPBPR/MHC-I interaction is reversed by specific peptides, related to their affinity. Mutational and small-angle X-ray scattering (SAXS) studies confirm the structural similarities of TAPBPR with tapasin. These results support a role of TAPBPR in stabilizing peptide-receptive conformation(s) of MHC-I, permitting peptide editing.