PMID- 18420581
OWN - NLM
STAT- MEDLINE
DCOM- 20080724
LR  - 20210206
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 283
IP  - 24
DP  - 2008 Jun 13
TI  - N-linked glycosylation selectively regulates the generic folding of HLA-Cw1.
PG  - 16469-76
LID - 10.1074/jbc.M709175200 [doi]
AB  - To resolve primary (glycosylation-assisted) from secondary 
      (glycosylation-independent) quality control steps in the biosynthesis of HLA 
      (human leukocyte antigen) class I glycoproteins, the unique N-linked 
      glycosylation site of the HLA-Cw1 heavy chain was deleted by site-directed 
      mutagenesis. The non-glycosylated Cw1S88G mutant was characterized by flow 
      cytometry, pulse-chase, co-immunoprecipitation, and in vitro assembly assays with 
      synthetic peptide ligands upon transfection in 721.221 and 721.220 cells. The 
      former provide a full set of primary as well as secondary chaperoning 
      interactions, whereas the latter are unable to perform secondary quality control 
      (e.g. proper class I assembly with peptide antigens) as a result of a functional 
      defect of the HLA-dedicated chaperone tapasin. In both transfectants, Cw1S88G 
      displayed a loss/weakening in its generic chaperoning interaction with 
      calreticulin and/or ERp57 and became redistributed toward calnexin, known to bind 
      the most unfolded class I conformers. Despite this, and quite unexpectedly, a 
      weak interaction with the HLA-dedicated chaperone TAP was selectively retained in 
      721.221. In addition, the ordered, stepwise acquisition of thermal 
      stability/peptide binding was disrupted, resulting in a heterogeneous ensemble of 
      Cw1S88G conformers with unorthodox and unprecedented peptide assembly features. 
      Because a lack of glycosylation and a lack of tapasin-assisted peptide loading 
      have distinct, complementary, and additive effects, the former is separable from 
      (and upstream of) the latter, e.g. primary quality control is suggested to 
      supervise a crucial, generic folding step preliminary to the acquisition of 
      peptide receptivity.
FAU - Martayan, Aline
AU  - Martayan A
AD  - Laboratory of Immunology, Regina Elena National Cancer Research Institute, Centro 
      della Ricerca Sperimentale, Via delle Messi d'Oro 156, 00158 Rome, Italy.
FAU - Sibilio, Leonardo
AU  - Sibilio L
FAU - Setini, Andrea
AU  - Setini A
FAU - Lo Monaco, Elisa
AU  - Lo Monaco E
FAU - Tremante, Elisa
AU  - Tremante E
FAU - Fruci, Doriana
AU  - Fruci D
FAU - Colonna, Marco
AU  - Colonna M
FAU - Giacomini, Patrizio
AU  - Giacomini P
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080417
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (HLA-C Antigens)
RN  - 0 (HLA-Cw1 antigen)
RN  - 0 (Ligands)
RN  - 0 (Membrane Transport Proteins)
RN  - 0 (Peptides)
RN  - 0 (tapasin)
RN  - EC 5.3.4.1 (Protein Disulfide-Isomerases)
RN  - EC 5.3.4.1. (PDIA3 protein, human)
SB  - IM
MH  - Biochemistry/methods
MH  - Glycosylation
MH  - HLA-C Antigens/*chemistry
MH  - Humans
MH  - Immunoprecipitation
MH  - Ligands
MH  - Membrane Transport Proteins/chemistry
MH  - Models, Biological
MH  - Mutagenesis, Site-Directed
MH  - Peptides/chemistry
MH  - Protein Binding
MH  - Protein Conformation
MH  - Protein Disulfide-Isomerases/chemistry
MH  - Protein Folding
MH  - Transfection
EDAT- 2008/04/19 09:00
MHDA- 2008/07/25 09:00
CRDT- 2008/04/19 09:00
PHST- 2008/04/19 09:00 [pubmed]
PHST- 2008/07/25 09:00 [medline]
PHST- 2008/04/19 09:00 [entrez]
AID - S0021-9258(20)71451-1 [pii]
AID - 10.1074/jbc.M709175200 [doi]
PST - ppublish
SO  - J Biol Chem. 2008 Jun 13;283(24):16469-76. doi: 10.1074/jbc.M709175200. Epub 2008 
      Apr 17.