TY - JOUR
T1 - Calreticulin and calnexin interact with different protein and glycan determinants during the assembly of MHC class I
AU - Harris, Michael R.
AU - Yu, Yik Y.L.
AU - Kindle, Cathy S.
AU - Hansen, Ted H.
AU - Solheim, Joyce C.
PY - 1998/6/1
Y1 - 1998/6/1
N2 - Before peptide binding, a variety of endoplasmic reticulum (ER) proteins are associated with class I including calnexin, TAP, calreticulin, and tapasin. Although the selective functions of any one of these ER proteins have been difficult to define, individually or in combination they perform two general chaperone functions for class I. They promote assembly of the class I heterotrimeric molecule (heavy (H) chain, β2m, and peptide) and they retain incompletely assembled complexes in the ER. In this study, we present evidence that calreticulin clearly differs from calnexin in how it associates with class I. Regarding the structural basis of the association, the oligosaccharide moiety in the α1 domain and the amino acid residue at position 227 in the α3 domain were both found to be critical for the interaction of class I with calreticulin. Interestingly, calreticulin displayed sensitivity to class I peptide binding even in TAP-deficient human or mouse cells. Thus, calreticulin is clearly more specific than calnexin in the structures and conformation of the class I molecule with which it can interact.
AB - Before peptide binding, a variety of endoplasmic reticulum (ER) proteins are associated with class I including calnexin, TAP, calreticulin, and tapasin. Although the selective functions of any one of these ER proteins have been difficult to define, individually or in combination they perform two general chaperone functions for class I. They promote assembly of the class I heterotrimeric molecule (heavy (H) chain, β2m, and peptide) and they retain incompletely assembled complexes in the ER. In this study, we present evidence that calreticulin clearly differs from calnexin in how it associates with class I. Regarding the structural basis of the association, the oligosaccharide moiety in the α1 domain and the amino acid residue at position 227 in the α3 domain were both found to be critical for the interaction of class I with calreticulin. Interestingly, calreticulin displayed sensitivity to class I peptide binding even in TAP-deficient human or mouse cells. Thus, calreticulin is clearly more specific than calnexin in the structures and conformation of the class I molecule with which it can interact.
UR - http://www.scopus.com/inward/record.url?scp=0032101943&partnerID=8YFLogxK
M3 - Article
C2 - 9605141
AN - SCOPUS:0032101943
VL - 160
SP - 5404
EP - 5409
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 11
ER -