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The outermost N-terminal region of tapasin facilitates folding of major histocompatibility complex class I

Roder, Gustav; Geironson Ulfsson, Linda LU ; Darabi, Anna LU ; Harndahl, Mikkel; Schafer-Nielsen, Claus; Skjodt, Karsten; Buus, Soren and Paulsson, Kajsa M LU (2009) In European Journal of Immunology 39(10). p.2682-2694
Abstract
Tapasin (Tpn) is an ER chaperone that is uniquely dedicated to MHC-I biosynthesis. It binds MHC-I molecules, integrates them into peptide-loading complexes, and exerts quality control of the bound peptides; only when an "optimal peptide" is bound will the MHC-I be released and exported to the cell surface for presentation to T cells. The exact mechanisms of Tpn quality control and the criteria for being an optimal peptide are still unknown. Here, we have generated a recombinant fragment of human Tpn, Tpn(1-87) (representing the 87 N-terminal and ER-luminal amino acids of the mature Tpn protein). Using a biochemical peptide-MHC-I-binding assay, recombinant Tpn(1-87) was found to specifically facilitate peptide-dependent folding of... (More)
Tapasin (Tpn) is an ER chaperone that is uniquely dedicated to MHC-I biosynthesis. It binds MHC-I molecules, integrates them into peptide-loading complexes, and exerts quality control of the bound peptides; only when an "optimal peptide" is bound will the MHC-I be released and exported to the cell surface for presentation to T cells. The exact mechanisms of Tpn quality control and the criteria for being an optimal peptide are still unknown. Here, we have generated a recombinant fragment of human Tpn, Tpn(1-87) (representing the 87 N-terminal and ER-luminal amino acids of the mature Tpn protein). Using a biochemical peptide-MHC-I-binding assay, recombinant Tpn(1-87) was found to specifically facilitate peptide-dependent folding of HLA-A*0201. Furthermore, we used Tpn(1-87) to generate a monoclonal antibody, alpha Tpn(1-87/80), specific for natural human Tpn and capable of cellular staining of ER localized Tpn. Using overlapping peptides, the epitope of alpha Tpn(1-87)/80 was located to Tpn(40-44), which maps to a surface-exposed loop on the Tpn structure. Together, these results demonstrate that the N-terminal region of Tpn can be recombinantly expressed and adopt a structure, which at least partially resembles that of WT Tpn, and that this region of Tpn features chaperone activity facilitating peptide binding of MHC-I. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Antibodies, Antigen processing, MHC-I
in
European Journal of Immunology
volume
39
issue
10
pages
2682 - 2694
publisher
John Wiley & Sons
external identifiers
  • wos:000271151000007
  • scopus:70350547789
ISSN
1521-4141
DOI
10.1002/eji.200939364
language
English
LU publication?
yes
id
e5363cdd-760a-4d92-bd19-e90ecd7a63fd (old id 1505827)
date added to LUP
2009-11-24 10:10:18
date last changed
2017-01-01 04:37:59
@article{e5363cdd-760a-4d92-bd19-e90ecd7a63fd,
  abstract     = {Tapasin (Tpn) is an ER chaperone that is uniquely dedicated to MHC-I biosynthesis. It binds MHC-I molecules, integrates them into peptide-loading complexes, and exerts quality control of the bound peptides; only when an "optimal peptide" is bound will the MHC-I be released and exported to the cell surface for presentation to T cells. The exact mechanisms of Tpn quality control and the criteria for being an optimal peptide are still unknown. Here, we have generated a recombinant fragment of human Tpn, Tpn(1-87) (representing the 87 N-terminal and ER-luminal amino acids of the mature Tpn protein). Using a biochemical peptide-MHC-I-binding assay, recombinant Tpn(1-87) was found to specifically facilitate peptide-dependent folding of HLA-A*0201. Furthermore, we used Tpn(1-87) to generate a monoclonal antibody, alpha Tpn(1-87/80), specific for natural human Tpn and capable of cellular staining of ER localized Tpn. Using overlapping peptides, the epitope of alpha Tpn(1-87)/80 was located to Tpn(40-44), which maps to a surface-exposed loop on the Tpn structure. Together, these results demonstrate that the N-terminal region of Tpn can be recombinantly expressed and adopt a structure, which at least partially resembles that of WT Tpn, and that this region of Tpn features chaperone activity facilitating peptide binding of MHC-I.},
  author       = {Roder, Gustav and Geironson Ulfsson, Linda and Darabi, Anna and Harndahl, Mikkel and Schafer-Nielsen, Claus and Skjodt, Karsten and Buus, Soren and Paulsson, Kajsa M},
  issn         = {1521-4141},
  keyword      = {Antibodies,Antigen processing,MHC-I},
  language     = {eng},
  number       = {10},
  pages        = {2682--2694},
  publisher    = {John Wiley & Sons},
  series       = {European Journal of Immunology},
  title        = {The outermost N-terminal region of tapasin facilitates folding of major histocompatibility complex class I},
  url          = {http://dx.doi.org/10.1002/eji.200939364},
  volume       = {39},
  year         = {2009},
}