Isolation and characterization of cDNA clones for the mouse thymocyte B cell antigen (ThB)

J Immunol. 1992 Oct 15;149(8):2615-8.

Abstract

The Thb locus is responsible for the expression of 15-kDa phosphatidyl inositol anchored molecules (ThB) on murine thymocytes and B cells. Thb expression as detected with mAb is polymorphic on B cells with two alleles, Thbh and Thb1 responsible for the high and low expression of ThB on B cells. The regulatory locus for Thb expression had been mapped with the Ly-6 cluster of genes to Chr 15. In our study we used expression cloning in COS cells to isolate cDNA clones that code for ThB after transfection; the cDNA products react with anti- ThB antibodies, but not with Ly-6A.2, -6B.2, -6C.2, or -6D.2 antibodies. One of these clones, pThB-A contains insert of 702 bases which was sequenced. The translated amino acid sequence has 11 cysteine residues, and together with the absence of potential N-linked glycosylation sites is similar to the structure of the Ly-6 molecules. The nucleotide and amino acid sequences of ThB cDNA were compared to those of Ly-6 genes and the Ly-6 related human CD59 and show clear homology. Finally using interspecies crosses, the structural Thb gene has been mapped to Chr 15; thus both structural and regulatory genes map to a similar site. The genetic map location near Ly-6 and the sequence similarity suggest that Thb and Ly-6 may have been derived from the same progenitor by gene duplication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Ly / genetics
  • Antigens, Surface / genetics*
  • B-Lymphocytes / immunology*
  • Base Sequence
  • Blotting, Northern
  • Blotting, Southern
  • Chromosome Mapping
  • DNA / chemistry
  • DNA / isolation & purification*
  • Mice
  • Molecular Sequence Data

Substances

  • Antigens, Ly
  • Antigens, Surface
  • DNA

Associated data

  • GENBANK/X63782