Characterization of the gene encoding the human LW blood group protein in LW+ and LW- phenotypes.
The LW blood group is carried by a 42-kD glycoprotein that belongs to the family of intercellular adhesion molecules. The LW gene is organized into three exons spanning an HindIII fragment of approximately 2.65 kb. The exon/intron architecture correlates to the structural domains of the protein and resembles that of other Ig superfamily members except that the signal peptide and the first Ig-like domain are encoded by the first exon. The 5'UT region (nucleotides -289 to +9) includes potential binding sites for various transcription factors (Ets, CACC, SP1, GATA-1, AP2) and exhibited a significant transcriptional activity after transfection in the erythroleukemic K562 cells. No obvious abnormality of the LW gene, including the 5'UT region, has been detected by sequencing polymerase chain reaction-amplified genomic DNA from RhD+ or RhD- donors and from an Rhnull variant that lacks the Rh and LW proteins on red blood cells. However, a deletion of 10 bp in exon 1 of the LW gene was identified in the genome of an LW (a- b-) individual (Big) deficient for LW antigens but carrying a normal Rh phenotype. The 10-bp deletion generates a premature stop codon and encodes a truncated protein without transmembrane and cytoplasmic domain. No detectable abnormality of the LW gene or transcript could be detected in another LW(a- b-) individual (Nic), suggesting the heterogeneity of these phenotypes.
Hermand
P
P
INSERM U76, Institut National de la Transfusion Sanguine, Paris, France.
Le Pennec
P Y
PY
Rouger
P
P
Cartron
J P
JP
Bailly
P
P
D000595:Amino Acid Sequence; D001483:Base Sequence; D001789:Blood Group Antigens / Q000235:genetics*; D015815:Cell Adhesion Molecules / Q000235:genetics*; D004247:DNA / Q000032:analysis; D006801:Humans; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D017421:Sequence Analysis
D001789:Blood Group Antigens; D015815:Cell Adhesion Molecules; C095100:ICAM4 protein, human; D004247:DNA