The protein made from a common allele of KIR3DL1 (3DL1*004) is poorly expressed at cell surfaces due to substitution at positions 86 in Ig domain 0 and 182 in Ig domain 1

J Immunol. 2003 Dec 15;171(12):6640-9. doi: 10.4049/jimmunol.171.12.6640.

Abstract

KIR3DL1 is an inhibitory HLA-B receptor of human NK and T cells that exhibits genetic and phenotypic polymorphism. KIR3DL1*004, a common allotype, cannot be detected on the surface of PBLs using the KIR3DL1-specific Ab DX9. The nature of this phenotype was investigated through comparison of 3DL1*004 with 3DL1*002, an allele giving high DX9 binding to cell surfaces. Analysis of Jurkat T cell transfectants with 3DL1*004 cDNA showed that 3DL1*004 is poorly expressed at the cell surface, but detectable intracellularly. Analysis of recombinant mutants made between 3DL1*004 and 3DL1*002 showed that polymorphism in Ig domains 0 and 1 (D0 and D1) causes the intracellular retention of 3DL1*004. Reciprocal point mutations were introduced into 3DL1*004 and 3DL1*002 at positions 44 and 86 of the D0 domain, where 3DL1*004 has unique residues, and at position 182 of the D1 domain, where 3DL1*004 resembles 3DL1*005, an allotype giving low DX9-binding phenotype. Leucine 86 in 3DL1*004 is the principal cause of its intracellular retention, with a secondary and additive contribution from serine 182. By contrast, glycine 44, which is naturally present in 3DL1*004, slightly increased cell surface expression when introduced into 3DL1*002. In 3DL1*004, the presence of leucine at position 86 corrupts the WSXPS motif implicated in proper folding of the KIR D0 Ig-like domain. This study demonstrates how a difference between KIR3DL1 allotypes in the D0 domain profoundly affects cell surface expression and function.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles*
  • Amino Acid Substitution / genetics*
  • Amino Acid Substitution / immunology*
  • Cell Line
  • Cell Membrane / genetics
  • Cell Membrane / immunology
  • Cell Membrane / metabolism
  • Clone Cells
  • Endoplasmic Reticulum / chemistry
  • Endoplasmic Reticulum / genetics
  • Endoplasmic Reticulum / immunology
  • Extracellular Space / chemistry
  • Extracellular Space / genetics
  • Extracellular Space / immunology
  • Humans
  • Immunoglobulins* / chemistry
  • Immunoglobulins* / genetics
  • Immunophenotyping
  • Jurkat Cells
  • Killer Cells, Natural / immunology
  • Killer Cells, Natural / metabolism*
  • Leucine / chemistry
  • Leucine / genetics
  • Polymorphism, Genetic / immunology
  • Protein Structure, Tertiary / genetics
  • Receptors, Immunologic / antagonists & inhibitors
  • Receptors, Immunologic / biosynthesis*
  • Receptors, Immunologic / chemistry
  • Receptors, Immunologic / genetics*
  • Receptors, KIR
  • Receptors, KIR3DL1
  • Serine / chemistry
  • Serine / genetics
  • Transfection

Substances

  • Immunoglobulins
  • KIR3DL1 protein, human
  • Receptors, Immunologic
  • Receptors, KIR
  • Receptors, KIR3DL1
  • Serine
  • Leucine