Localization of the gene encoding the alpha 2 subunit of the human VLA-2 receptor to chromosome 5q23-31.

The alpha 2 subunit of the VLA-2 receptor (CD49B) was mapped to human chromosome 5 by several independent approaches. First, the expression of the alpha 2 subunit at the protein level was investigated in a panel of human-mouse hybrid cell lines. Cell surface expression was detected by indirect immunofluorescence with monoclonal anti-alpha 2 antibody 12F1. Intracellular alpha 2 antigen was detected by immunostaining of whole cell extracts or of immunoprecipitated 12F1 antigen with the monoclonal antibodies 3H8 and 5C5. Second, the presence of human genomic alpha 2 sequences in the panel of human-mouse hybrids was detected by PCR, using primers derived from the published alpha 2 cDNA sequence. The specificity of the amplification product was shown by direct sequencing. The results of the PCR study were confirmed by amplifying a CD14 gene fragment, known to map to chromosome 5. Finally, in situ hybridization with a 3H-labeled 1040-bp cDNA probe, also obtained by PCR, confirmed and refined the localization of CD49B on chromosome 5 at q23-31.