PMID- 1824944
OWN - NLM
STAT- MEDLINE
DCOM- 19910307
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 266
IP  - 4
DP  - 1991 Feb 5
TI  - Characterization of truncated alpha chain products from human, rat, and mouse 
      high affinity receptor for immunoglobulin E.
PG  - 2639-46
AB  - The high affinity receptor for immunoglobulin E (IgE) is a tetrameric structure 
      (alpha beta gamma 2) consisting of non-covalently associated subunits: one 
      IgE-binding alpha chain, one 4-fold membrane spanning beta chain, and two 
      disulfide-linked gamma chains. Here, we have engineered alpha cDNA constructs 
      (alpha trunc) encoding exclusively the leader peptide and the extracellular 
      domain of the alpha subunit. Transfection of human alpha trunc into COS-7 cells 
      resulted in the secretion of soluble IgE-binding polypeptides. By contrast, the 
      polypeptides generated from rat and mouse alpha trunc transfections were 
      sequestered in the endoplasmic reticulum and degraded even though they appeared 
      to fold properly as judged by their capacity to bind IgE. Stable transfectants 
      with human alpha trunc were obtained from a dihydrofolate reductase-deficient 
      Chinese hamster ovary cell line. Several clones secreted substantial amounts (0.1 
      microgram/ml/10(6) cells) of IgE-binding polypeptides. The dissociation rate of 
      bound IgE from this soluble truncated alpha (kappa-1 = 4.9 x 10(-6) s-1 at 25 
      degrees C) was characteristic of receptors on intact cells. After treatment with 
      tunicamycin, the transfectants secreted unglycosylated 18-kDa polypeptides which 
      could also bind IgE. These unglycosylated products had a tendency to form dimers 
      and higher oligomers which were resistant to treatment by sodium dodecyl sulfate 
      and reducing agents. These data demonstrate unequivocally that the extracellular 
      domain of the alpha subunit is sufficient to mediate high affinity binding of 
      IgE. Furthermore, posttranslational addition of carbohydrates is not required for 
      proper folding and function of the receptor binding site. The truncated human 
      alpha should be a suitable reagent for crystallographic analysis and for detailed 
      analysis of the receptor binding sites.
FAU - Blank, U
AU  - Blank U
AD  - Molecular Allergy and Immunology Section, National Institute of Allergy and 
      Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852.
FAU - Ra, C S
AU  - Ra CS
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 (Antigens, Differentiation, B-Lymphocyte)
RN  - 0 (Receptors, Fc)
RN  - 0 (Receptors, IgE)
RN  - 11089-65-9 (Tunicamycin)
RN  - 37341-29-0 (Immunoglobulin E)
SB  - IM
MH  - Animals
MH  - Antigens, Differentiation, B-Lymphocyte/*genetics/metabolism
MH  - Base Sequence
MH  - Cell Line
MH  - Chemical Precipitation
MH  - Cloning, Molecular
MH  - Cricetinae
MH  - Electrophoresis, Polyacrylamide Gel
MH  - Gene Expression Regulation
MH  - Humans
MH  - Immunoglobulin E/*metabolism
MH  - Kinetics
MH  - Mice
MH  - Molecular Sequence Data
MH  - Protein Processing, Post-Translational
MH  - Rats
MH  - Receptors, Fc/*genetics/metabolism
MH  - Receptors, IgE
MH  - Solubility
MH  - Transfection
MH  - Tunicamycin/pharmacology
EDAT- 1991/02/05 00:00
MHDA- 1991/02/05 00:01
CRDT- 1991/02/05 00:00
PHST- 1991/02/05 00:00 [pubmed]
PHST- 1991/02/05 00:01 [medline]
PHST- 1991/02/05 00:00 [entrez]
AID - S0021-9258(18)52292-4 [pii]
PST - ppublish
SO  - J Biol Chem. 1991 Feb 5;266(4):2639-46.