Immunogenetics

, Volume 52, Issue 1–2, pp 9–11

Identification of novel Tapasin polymorphisms and linkage disequilibrium to MHC class I alleles

  • Anthony P. Williams
  • Steven Bevan
  • Mike Bunce
  • Richard Houlston
  • Kenneth I. Welsh
  • Tim Elliott
Original Paper

DOI: 10.1007/s002510000244

Cite this article as:
Williams, A., Bevan, S., Bunce, M. et al. Immunogenetics (2000) 52: 9. doi:10.1007/s002510000244

Abstract.

Tapasin is a Mr 48,000 glycoprotein and has a specialized role in MHC class I-restricted antigen presentation. It is encoded by a gene which maps centromeric to the MHC class II region of human Chromosome 6 within 200 kb of HLA-DP. There is variable dependence upon tapasin for MHC class I expression among different MHC class I alleles. HLA-B*4402 and to a lesser extent HLA-A1 and B8 are tapasin dependent, whereas HLA-B27, A2 and to a lesser extent B7 and A3 are tapasin independent. We investigated whether tapasin is polymorphic and whether these Tapasin alleles are in linkage with any MHC class I alleles. We identified three new mutations within intron 4, which are in a particular linkage with the previously described exon 4 (G16003C) dimorphism. The intronic mutations are G16146T, G16232A, and T16317A (numbering according to cosmid clone F0811; GenBank accession number Z97184). The allele frequency of Tapasin*01 (G16003) was 0.47 and Tapasin*02 (C16003) was 0.53 in this UK population. Four of the eight possible intronic haplotypes were identified and their cis linkage with the tapasin dimorphism ascertained. Tapasin*01 was associated with all the identified haplotypes, while Tapasin*02 was only associated with the wild-type intronic sequence (GGT). There was no significant linkage (P>0.01) of the Tapasin dimorphism or new Tapasin alleles to any of the MHC class I A, B, or C alleles studied or to the extended A1 B8 DR3 haplotype.

Tapasin Polymorphism MHC class I Intron Haplotype 

Copyright information

© Springer-Verlag 2000

Authors and Affiliations

  • Anthony P. Williams
    • 1
  • Steven Bevan
    • 2
  • Mike Bunce
    • 3
  • Richard Houlston
    • 2
  • Kenneth I. Welsh
    • 3
  • Tim Elliott
    • 1
  1. 1.Nuffield Department of Medicine, Institute of Molecular Medicine, Oxford, OX3 9DS, UK
  2. 2.Section of Cancer Genetics, Institute of Cancer Research, Sutton, UK
  3. 3.Oxford Tissue Typing Laboratory, Churchill Hospital, Oxford, UK

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