Assignment of the CD45-AP Gene to the Centromeric End of Mouse Chromosome 19 and Human Chromosome 11q13.1–q13.3

CD45-AP is a recently identified phosphorylated protein that specifically associates with the leukocyte-specific transmembrane glycoprotein CD45. The gene for CD45-AP, Ptprcap (protein tyrosine phosphatase, receptor type c polypeptide associated protein), was mapped in mouse by typing the progeny of two multilocus crosses using the mouse CD45-AP cDNA as a Southern hybridization probe. The CD45-AP gene mapped to the centromeric region of Chr 19 proximal to the genes Fth, Cd5, and Pcna-rs. The gene for the human CD45-AP homologue, PTPRCAP, was localized to chromosome band 11q13.1-q13.3 by fluorescence in situ hybridization using human genomic CD45-AP DNA as a hybridization probe. The genetic mapping of the Ptprcap/PTPRCAP genes extends the previously defined synteny conservation of various genes that have been assigned to these regions of the mouse and the human chromosomes.