Abstract
With β2‐microglobulin− (β2m−) cell lines such as R1E/Db, the surface expression of class I major histocompatibility complex molecules is greatly impaired, and class I molecules that are on the surface are generally misfolded. To determine whether β2m must be continually present with the class I heavy chain for the class I molecule to reach the surface in a folded conformation, a sequence encoding an endoplasmic reticulum (ER) retention signal (KDEL) was attached onto the 3′ end of a β2m cDNA. After this chimeric cDNA was transfected into R1E/Db cells, β2m‐KDEL protein was detectable by an anti‐β2m serum within the cells but not at the cell surface. Interestingly, R1E/Db cells transfected with β2m‐KDEL were found to express a high level of conformationally correct Db molecules at the cell surface. This observation implies that β2m has a critical and temporal role in the de novo folding of the class I heavy chain. We propose that the critical time for β2m association is when the class I molecule is docked with the transporter associated with antigen processing (TAP) and first interacts with peptide.
Original language | English (US) |
---|---|
Pages (from-to) | 3011-3016 |
Number of pages | 6 |
Journal | European Journal of Immunology |
Volume | 25 |
Issue number | 11 |
DOIs | |
State | Published - Nov 1995 |
Externally published | Yes |
Keywords
- Conformation
- Endoplasmic reticulum
- Majro histocompatibility complex class I
- R1E/D
- β ‐microglobulin
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology