Direct observation of disordered regions in the major histocompatibility complex class II-associated invariant chain.
Invariant chain (Ii) is a trimeric membrane protein which binds and stabilizes major histocompatibility complex class II heterodimers in the endoplasmic reticulum and lysosomal compartments of antigen-presenting cells. In concert with an intracellular class II-like molecule, HLA-DM, Ii seems to facilitate loading of conventional class II molecules with peptides before transport of the class II-peptide complex to the cell surface for recognition by T cells. The interaction of Ii with class II molecules is thought to be mediated in large part through a region of 24 amino acids (the class II-associated Ii peptide, CLIP) which binds as a cleaved moiety in the antigenic peptide-binding groove of class II molecules in HLA-DM-deficient cell lines. Here we use nuclear magnetic resonance techniques to demonstrate that a soluble recombinant Ii ectodomain contains significant disordered regions which probably include CLIP.
Jasanoff
A
A
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Park
S J
SJ
Wiley
D C
DC
D000595:Amino Acid Sequence; D000944:Antigens, Differentiation, B-Lymphocyte / Q000737:chemistry* / Q000235:genetics; D016477:Artifacts; D000949:Histocompatibility Antigens Class II / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry
D000944:Antigens, Differentiation, B-Lymphocyte; D000949:Histocompatibility Antigens Class II; D010446:Peptide Fragments; D011994:Recombinant Proteins; C045084:invariant chain