Immunogenetics

, Volume 36, Issue 3, pp 175–181

Genomic organization and chromosomal location of the human gene encoding the B-lymphocyte activation antigen B7

  • Annamalai Selvakumar
  • Bhaskara K. Mohanraj
  • Roger L. Eddy
  • Thomas B. Shows
  • Perrin C. White
  • Bo Dupont
Original Articles

DOI: 10.1007/BF00661094

Cite this article as:
Selvakumar, A., Mohanraj, B.K., Eddy, R.L. et al. Immunogenetics (1992) 36: 175. doi:10.1007/BF00661094

Abstract

The human B lymphocyte activation antigen B7 provides regulatory signals for T lymphocytes as a consequence of binding to its ligands CD28 and CTLA-4. The cDNA for B7 has previously been isolated and predicted to encode a type I membrane protein. The predicted polypeptide has a secretory signal peptide followed by two contiguous Ig-like domains, a hydrophobic transmembrane region and a short cytoplasmic tail. Here we report the exon-intron genomic organization of human B7 and the chromosomal location. The gene has six exons that span approximately 32 kilobases of DNA. Exon 1 is not translated and the second exon contains the initiation ATG codon and encodes a predicted signal peptide. This gene structure is characteristic for several eukaryotic genes with tissue-specific expression. The third and fourth exons correspond to two Ig-like domains whereas the fifth and sixth exons encode respectively the trans-membrane portion and the cytoplasmic tail. This close relationship between exons and functional domains is a characteristic feature of genes of the Ig superfamily. Cell surface expression of the B7 gene product has previously been mapped to human chromosome 12 by antibody reactivity with the B7-specific monoclonal antibody BB-1. We here demonstrate that theB7 gene is located to theq21-qter region of chromosome 3 by DNA blot analysis of human × rodent somatic cell hybrids.

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Annamalai Selvakumar
    • 1
  • Bhaskara K. Mohanraj
    • 1
  • Roger L. Eddy
    • 2
  • Thomas B. Shows
    • 2
  • Perrin C. White
    • 3
  • Bo Dupont
    • 1
  1. 1.Human Immunogenetics LaboratorySloan-Kettering Institute for Cancer ResearchNew YorkUSA
  2. 2.Department of Human GeneticsRosewell Park Memorial InstituteBuffaloUSA
  3. 3.Division of Pediatric EndocrinologyCornell University Medical CollegeNew YorkUSA

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