Proteolysis of the class II-associated invariant chain generates a peptide binding site in intracellular HLA-DR molecules. Proc. Natl. Acad. Sci. USA. 1991. 88: 3150-3154.
J Immunol
; 187(3): 1076-80, 2011 Aug 01.
Article
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| MEDLINE
| ID: mdl-21772034
HLA-DR molecules are heterodimeric transmembrane glycoproteins that associate intracellularly with a polypeptide known as the invariant (I) chain. Shortly before expression of the HLA-DR αß dimer on the cell surface, however the I chain is removed from the intracellular αßI complex by a mechanism thought to involve proteolysis . In this report, we show that treatment of purified αßI with the cysteine proteinase cathepsin B results in the specific proteolysis of the HLA-DR-associated I chain in vitro. As a consequence of this, the I chain is removed and free αß dimers are released from αßI. Although αßI fails to bind an immunogenic peptide, the released αß dimers acquire the ability to bind the peptide after proteolysis of the I chain. These results suggest that the I chain inhibits immunogenic peptide binding to αßI early during intracellular transport and demonstrate that proteolysis is likely to be the in vivo mechanism of I chain removal.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Péptidos
/
Antígenos de Diferenciación de Linfocitos B
/
Antígenos HLA-DR
/
Antígenos de Histocompatibilidad Clase II
/
Líquido Intracelular
Tipo de estudio:
Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
J Immunol
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos