Human C21orf63 is a Heparin-binding Protein

• Published in: Journal of biochemistry (Tokyo) 2009-09, Vol.146 (3), p.369-373
• Main Authors: Mitsunaga, Kanae, Harada-Itadani, Jun, Shikanai, Toshihide, Tateno, Hiroaki, Ikehara, Yuzuru, Hirabayashi, Jun, Narimatsu, Hisashi, Angata, Takashi
• Format: Article
• Language: English
• Subjects: C21orf63; Cloning, Molecular; Databases, Protein; Epithelial Cells - metabolism; Fluorescent Antibody Technique; Galectins; Gastric Mucosa - metabolism; Gene Expression; glycan microarray; Glycosaminoglycans - metabolism; heparan sulphate; heparin; Heparin - analogs & derivatives; Heparin - metabolism; Heparitin Sulfate - metabolism; Humans; Immobilized Proteins - metabolism; lectins; Lectins - chemistry; Lectins - immunology; Lectins - metabolism; Membrane Proteins - chemistry; Membrane Proteins - immunology; Membrane Proteins - metabolism; Microarray Analysis; Microscopy, Fluorescence; Mutant Proteins - chemistry; Mutant Proteins - immunology; Mutant Proteins - metabolism; Organ Specificity; Protein Binding; Protein Structure, Tertiary; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - immunology; Recombinant Fusion Proteins - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Stomach Neoplasms - metabolism
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/jb/mvp079

Human C21orf63 is a type-1 transmembrane protein of hitherto unknown function, with two repeats of putative 'galactose-binding lectin domains'. By using glycan microarray analysis and other assays, we found that human C21orf63 interacts with heparin and to a lesser extent with heparan sulphate. The C-terminal galactose-binding lectin domain of C21orf63 is necessary for heparin binding. The inability of other human proteins with galactose-binding lectin domains to interact with heparin suggests that heparin binding is a unique property of C21orf63. Results of real-time polymerase chain reaction and tissue immunostaining imply that C21orf63 is expressed on epithelia of various human tissues.