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Major histocompatibility complex class I molecules interact with both subunits of the transporter associated with antigen processing, TAP1 and TAP2
Author(s) -
Powis Simon J.
Publication year - 1997
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/eji.1830271040
Subject(s) - transporter associated with antigen processing , calreticulin , mhc class i , antigen processing , major histocompatibility complex , biology , cd74 , mhc restriction , microbiology and biotechnology , calnexin , antigen presentation , antigen , genetics , in vitro , cytotoxic t cell , endoplasmic reticulum
Abstract Prior to loading antigenic peptides, assembled major histocompatibility complex (MHC) class I molecules associate with the transporter associated with antigen processing (TAP) in a complex which also includes calreticulin and a recently described component, tapasin. The interaction of MHC class I molecules has been characterized as occurring exclusively with the TAP1 chain of the TAP heterodimer. In contrast, as described here, in the TAP‐deficient human cell line T2, MHC class I molecules interact with a transfected rat TAP2 polypeptide in addition to rat TAP1. Furthermore, this interaction with TAP2 also involves calreticulin and tapasin. An association with both TAP polypeptides would presumably further enhance the efficiency of peptide loading of MHC class I molecules by allowing more than one MHC class I allele proximity to the site of peptide supply on each TAP complex.