Polymorphism R62W results in resistance of CD23 to enzymatic cleavage in cultured cells

Genes Immun. 2007 Apr;8(3):215-23. doi: 10.1038/sj.gene.6364376. Epub 2007 Feb 15.

Abstract

A nonsynonymous single nucleotide polymorphism (SNP) of the low-affinity IgE receptor (FcvarepsilonRII/CD23) gene resulting in an arginine to tryptophan exchange at amino-acid position 62 (R62W) has been associated with enhanced T-cell responses to antigen in allergic subjects. To explore the mechanism, a CD23(a) cDNA was cloned into the plasmid pCMVScript-CD23a-C with a C allele (R62). The pCMVScript-CD23a-T with T (W62) was produced using a site-directed mutagenesis approach. The pCMVScript-CD23a-C only (CC), mixture of pCMVScript-CD23a-T and pCMVSCript-CD23a-C (CT) and pCMVScript-CD23a-T only (TT) plasmids were transfected in Cos-7 cells at equivalence in transfection efficiency. No soluble CD23 was released from TT transfectants whereas a higher level of soluble CD23 was detected in CC than in CT transfectants. Human leukocyte elastase (HLE), cathepsin G, the dust mite allergen Der p I and ADAM 33 (A disintegrin and metalloproteinase) were found to cleave membrane CD23 in CC but not in TT transfectants, implying the resistance of CD23 to enzymatic cleavage associated with T mutant. Addition of tunicamycin resulted in the resistance of CD23 to Der p I mediated cleavage in CC but no change in TT transfectants. These results indicate that R62W influences the stability of membrane CD23 molecules due to possibly diminished N-glycosylation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADAM Proteins / metabolism
  • Amino Acid Sequence
  • Amino Acid Substitution
  • Animals
  • Antigens, Dermatophagoides / metabolism
  • Arthropod Proteins
  • Base Sequence
  • COS Cells
  • Cathepsin G
  • Cathepsins / metabolism
  • Chlorocebus aethiops
  • Cysteine Endopeptidases
  • DNA, Complementary / genetics
  • Glycosylation
  • Humans
  • In Vitro Techniques
  • Leukocyte Elastase / metabolism
  • Polymorphism, Single Nucleotide*
  • Receptors, IgE / chemistry
  • Receptors, IgE / genetics*
  • Receptors, IgE / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Serine Endopeptidases / metabolism
  • Transfection
  • Tunicamycin / pharmacology

Substances

  • Antigens, Dermatophagoides
  • Arthropod Proteins
  • DNA, Complementary
  • Receptors, IgE
  • Recombinant Proteins
  • Tunicamycin
  • Cathepsins
  • Serine Endopeptidases
  • CTSG protein, human
  • Cathepsin G
  • Leukocyte Elastase
  • Cysteine Endopeptidases
  • Dermatophagoides pteronyssinus antigen p 1
  • ADAM Proteins
  • ADAM33 protein, human