Assignment of the GLG1 gene for MG-160, a fibroblast growth factor and E-selectin binding membrane sialoglycoprotein of the Golgi apparatus, to chromosome 16q22-q23 by fluorescence in situ hybridization

MG-160, originally isolated from rat brain, is a conserved membrane sialoglycoprotein residing in the medial cisternae of the Golgi apparatus of virtually all cells. MG-160 appears in the developing chicken embryo as early as 12 h and persists in most cells throughout embryonic development and in the adult animal. The early appearance and ubiquitous presence of MG-160 suggest that the protein plays an important role in the biogenesis and function of the Golgi apparatus. The rat cDNA of MG-160 encodes a polypeptide of 1171 amino acids (AA) with a short cytoplasmic carboxy-terminus of 13 aa, a single transmembrane domain, and a large cysteine-rich intraluminal domain. MG-160 binds basic fibroblast growth factor (bFGF) and displays 90% identity of amino acids with CFR, a cystein-rich receptor for several fibroblast growth factors (FGFs), that was isolated form chicken embryos. However, unlike the fibroblast growth factor receptors (FGFRs) involved in signal transduction, MG-160 and its chicken homologue CFR do not display the extracellular IG-like repeats and the intracytoplasmic tyrosin kinase domains. In addition to CFR, MG-160 is highly homologous to ESL-1, a ligand for E-selectin. 16 refs., 1 fig.