PMID- 7713932
OWN - NLM
STAT- MEDLINE
DCOM- 19950515
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 270
IP  - 14
DP  - 1995 Apr 7
TI  - Glycosylation of human truncated Fc epsilon RI alpha chain is necessary for 
      efficient folding in the endoplasmic reticulum.
PG  - 8249-56
AB  - The high affinity immunoglobulin E (IgE) receptor is an alpha beta gamma 2 
      tetrameric complex. The truncated extracellular segment (alpha t) of the heavily 
      glycosylated alpha chain is sufficient for high affinity binding of IgE. Here we 
      have expressed various alpha t mutants in eukaryotic and prokaryotic cells to 
      analyze the role of glycosylation in the folding, stability, and secretion of 
      alpha t. All seven N-linked glycosylation sites in alpha t are glycosylated and 
      their mutations have an additive effect on the folding and secretion of alpha t. 
      Mutation of the seven N-glycosylation sites (delta 1-7 alpha t) induces 
      misfolding and retention of alpha t in the endoplasmic reticulum. Similarly, 
      tunicamycin treatment reduces substantially the folding efficiency of wild-type 
      alpha t. In contrast, no difference in folding efficiency is detected between 
      wild-type alpha t and delta 1-7 alpha t expressed in Escherichia coli. In 
      addition, maturation of N-linked oligosaccharides and addition of O-linked 
      carbohydrates are not required for either the transport or the IgE-binding 
      function of alpha t. Furthermore, complete enzymatic deglycosylation does not 
      affect the stability and the IgE-binding capacity of alpha t. Therefore, 
      glycosylation is not intrinsically necessary for proper folding of alpha t but is 
      required for folding in the endoplasmic reticulum. Our data are compatible with 
      the concept that specific interactions between N-linked oligosaccharides and the 
      folding machinery of the endoplasmic reticulum are necessary for efficient 
      folding of alpha t in eukaryotic cells.
FAU - Letourneur, O
AU  - Letourneur O
AD  - Molecular Allergy and Immunology Section, National Institute of Allergy and 
      Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, 
      USA.
FAU - Sechi, S
AU  - Sechi S
FAU - Willette-Brown, J
AU  - Willette-Brown J
FAU - Robertson, M W
AU  - Robertson MW
FAU - Kinet, J P
AU  - Kinet JP
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Antibodies)
RN  - 0 (Peptides)
RN  - 0 (Receptors, IgE)
RN  - 11089-65-9 (Tunicamycin)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - Antibodies/immunology
MH  - Biological Transport
MH  - CHO Cells
MH  - Cell Line
MH  - Cricetinae
MH  - Endoplasmic Reticulum/*metabolism
MH  - Glycosylation
MH  - Humans
MH  - Molecular Sequence Data
MH  - Mutagenesis, Site-Directed
MH  - Peptides/immunology
MH  - *Protein Folding
MH  - Receptors, IgE/genetics/*metabolism
MH  - Tunicamycin/pharmacology
EDAT- 1995/04/07 00:00
MHDA- 1995/04/07 00:01
CRDT- 1995/04/07 00:00
PHST- 1995/04/07 00:00 [pubmed]
PHST- 1995/04/07 00:01 [medline]
PHST- 1995/04/07 00:00 [entrez]
AID - S0021-9258(18)94683-1 [pii]
AID - 10.1074/jbc.270.14.8249 [doi]
PST - ppublish
SO  - J Biol Chem. 1995 Apr 7;270(14):8249-56. doi: 10.1074/jbc.270.14.8249.