Molecular cloning of a human macrophage lectin specific for galactose.
The murine Mac-2 protein is a galactose- and IgE-binding lectin secreted by inflammatory macrophages. We describe here the cloning and characterization of a cDNA representing the human homolog of Mac-2 (hMac-2). The amino acid sequence derived from the hMac-2 cDNA indicates that the protein is evolutionarily highly conserved, with 85% of its amino acid residues being similar to those in the murine homolog. This conservation is especially marked in the carboxyl-terminal lectin domain. The amino-terminal half of the protein is less conserved but still contains the repetitive proline-glycine-rich motif seen in the mouse protein. hMac-2 synthesized in vitro is recognized by the M3/38 monoclonal antibody to Mac-2 and binds to the desialylated glycoprotein asialofetuin and to laminin, a major component of basement membranes. These findings are discussed in the context of the potential functions of hMac-2.
Molecular Immunology Laboratory, Massachusetts General Hospital, Boston.
B J
BJ
Cherayil
S
S
Chaitovitz
C
C
Wong
S
S
Pillai
D000595:Amino Acid Sequence; D000818:Animals; D000943:Antigens, Differentiation / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods; D005690:Galactose / Q000378:metabolism*; D037502:Galectin 3; D015723:Gene Library; D006801:Humans; D037102:Lectins / Q000235:genetics* / Q000378:metabolism; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D000943:Antigens, Differentiation; D037502:Galectin 3; D037102:Lectins; D005690:Galactose