Chromosome 3q (22-ter) encodes the human transferrin receptor

The human transferrin receptor is an integral membrane glycoprotein of 180,000 molecular weight (mol. wt.) formed from two subunits of 90,000 mol. wt. A clone panel of Chinese hamster-human somatic cell hybrids was screened using a single cell plating cytotoxicity assay and rabbit antiserum raised to purified human transferrin receptor. Chromosome 3 displayed the highest rate of concordance with the presence of human transferrin receptor, as assayed by cytotoxicity. Antitransferrin receptor serum-resistant segregants of chromosome 3 positive, receptor-positive hybrids were selected, using antiserum and complement. The segregants consistently lost chromosome 3. 125I human transferrin binding studies confirmed synteny between the functional human transferrin receptor and chromosome 3. Examination of hybrids with either translocated or deleted chromosome 3's allows regional mapping to 3q(22-ter).