Analysis of D2d: a D-region class I gene.
The mouse major histocompatibility complex is composed of several genes arranged into the K, D, Qa, and Tla regions. The D region of the BALB/c mouse includes genes D2d, D3d, and D4d, in addition to H-2Dd and H-2Ld. We have determined the DNA sequence of the D2d gene and compared it with the known sequences of several class I genes. The exon/intron structure of the D2d gene is similar to other class I genes. It also contains similar 5' regulatory elements. A frameshift occurs in exon seven, resulting in a gene product with a truncated cytoplasmic tail. To examine the surface expression of the D2d molecule, we generated an exon-shuffled construct containing the promoter and exons 1-3, encoding the signal peptide, alpha 1, and alpha 2 external domains of the D2d gene linked to exons 4-8, encoding the alpha 3, transmembrane and cytoplasmic domains, of the H-2Dd gene. The construct was transfected into mouse L cells, and a protein was detected at the cell surface by a monoclonal antibody (mAb) specific for the alpha 3 domain of H-2Dd, as well as by other class I-specific mAbs. Although D2d is expressed at low levels, it may be a functional class I gene that most probably evolved from a Qa region gene.
Hedley
M L
ML
University of Texas Southwestern Medical Center, Dallas 75235.
Hunt
S W
SW
Brorson
K A
KA
Andris
J S
JS
Hood
L
L
Forman
J
J
Tucker
P W
PW
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D003593:Cytoplasm / Q000032:analysis; D005805:Genes, MHC Class I; D006183:H-2 Antigens / Q000235:genetics* / Q000302:isolation & purification; D007739:L Cells / Q000032:analysis; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic
D006183:H-2 Antigens