Ermap, a gene coding for a novel erythroid specific adhesion/receptor membrane protein

Ermap (erythroid membrane-associated protein), a gene coding for a novel tr ansmembrane protein produced exclusively in erythroid cells, is described. It is mapped to murine Chromosome 4, 57 cM distal to the centromere. The in itial cDNA clone was isolated from a day 9 murine embryonic erythroid cell cDNA library. The predicted peptide sequence suggests that ERMAP is a trans membrane protein with two extracellular immunoglobulin folds, as well as a highly conserved B30.2 domain and several phosphorylation consensus sequenc es in the cytoplasmic region. ERMAP shares a high homology throughout the e ntire peptide with butyrophilin, a glycoprotein essential for milk lipid dr oplet formation and release. A GFP-ERMAP fusion protein was localized to th e plasma membrane and cytoplasmic vesicles in transiently transfected 293T cells. Northern blot analysis and in-situ hybridization demonstrated that E rmap expression was restricted to fetal and adult erythroid tissues. ERMAP is likely a novel adhesion/receptor molecule specific for erythroid cells. (C) 2000 Elsevier Science B.V. All rights reserved.