Cloning and sequence analysis of the human MG160, a fibroblast growth factor and E-selectin binding membrane sialoglycoprotein of the Golgi apparatus.
The amino acid sequence of MG160, a membrane sialoglycoprotein of the medial cisternae of the rat Golgi apparatus, is more than 90% identical with CFR, a fibroblast growth factor (FGF) binding protein of chicken membranes, and with ESL-1, a ligand for E-selectin of plasma membranes of myeloid cells; furthermore, MG160, isolated by immunoaffinity chromatography from rat brain membranes, binds to basic FGF. The gene for MG160 has been assigned to human chromosome 16q22-23. To characterize this protein further in the human, its cDNA was cloned and sequenced. The protein has a large luminal domain composed of an initial proline-glutamine-rich segment, encoded by an uninterrupted exonic sequence of several CAG-CAA repeats. Expansion of CAG repeats has been implicated in the etiology of several neurodegenerative diseases. The proline-glutamine-rich segment is followed by 16 cysteine-rich repeats that contain five potential asparagine-linked glycosylation sites, which are conserved in the human, rat, mouse, and chicken. The large intralumenal domain of the protein is followed by a single transmembrane domain and a 13-amino-acid cytoplasmic carboxy-terminal tail, which is identical to that in the chicken, rat, and mouse. The overall amino acid identifies between MG160, CFR, and ESL-1 range from 88% to 95%. In several human fetal and adult tissues, three mRNA transcripts for MG160 of 10 kb, 5 kb, and 3.8 kb were identified by Northern blot analysis of poly(A)-selected mRNAs. These transcripts may represent alternatively spliced mRNAs of the protein or mRNAs encoding closely related proteins of the Golgi apparatus and/or plasma membranes.
Mourelatos
Z
Z
Department of Pathology, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
Gonatas
J O
JO
Cinato
E
E
Gonatas
N K
NK
D000328:Adult; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics*; D019040:E-Selectin / Q000378:metabolism; D005091:Exons / Q000235:genetics; D005346:Fibroblast Growth Factors / Q000378:metabolism; D006056:Golgi Apparatus / Q000737:chemistry*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011485:Protein Binding; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012795:Sialoglycoproteins / Q000235:genetics*; D018911:Trinucleotide Repeats / Q000235:genetics
D018076:DNA, Complementary; D019040:E-Selectin; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; D012795:Sialoglycoproteins; C086711:cysteine-rich fibroblast growth factor receptor; D005346:Fibroblast Growth Factors