Stromal Cell Derived Factor 2 (SDF2)

By use of the signal sequence trap method, Hamada et al. (1996) isolated a cDNA encoding a novel secretory protein, Sdf2, from the mouse stromal cell line ST2. The Sdf2 cDNA encodes a putative 211-amino acid protein that includes a 30-amino acid hydrophobic signal peptide. Because the protein lacks a hydrophobic region in addition to that at the N terminus, the authors stated that the protein is likely to be a secretory and not a membrane protein. Sdf2 has significant similarity to hydrophilic segments of yeast mannosyltransferases Pmt1p and Pmt2p which reside in the endoplasmic membrane and transfer mannose residues from dolichyl phosphate D-mannose to specific ser/thr residues. Northern blot analysis of adult mouse organ mRNA demonstrated ubiquitous expression of Sdf2.