Molecular cloning and expression of cDNA encoding a galactose/N-acetylgalactosamine-specific lectin on mouse tumoricidal macrophages.
We previously reported that the mouse macrophage galacose and N-acetylgalactosamine-specific lectin (MMGL) may participate in the binding of the macrophages to tumor cells [Oda, S., Sato, M., Toyoshima, S., & Osawa, T. (1989) J. Biochem. 105, 1040-1043]. We now report the cloning and characterization of a cDNA encoding MMGL. The MMGL gene encoded a protein consisting of 304 amino acid residues with a molecular weight of 34,595. The deduced amino acid sequence indicated that MMGL had a single membrane-spanning region, three leucine zipper-like domains, and a carbohydrate recognition domain. Two N-glycosylation sites were found in the extracellular region of MMGL, corresponding to the heavy N-glycosylation in the native MMGL. Comparison of the amino acid sequence of MMGL with those of rat hepatic lectins revealed a high overall sequence homology. The sequence homology was especially high in the putative membrane-spanning region and carbohydrate recognition domain. There was, however, a region of 25 amino acids which did not exist on hepatic lectins. The MMGL cDNA without the region encoding the putative membrane-spanning region and intracellular region was expressed in Escherichia coli. The expressed protein had galactose-binding activity and its sugar-binding specificity was same as that of the native lectin.
Sato
M
M
Division of Chemical Toxicology and Immunochemistry, Faculty of Pharmaceutical Sciences, University of Tokyo.
Kawakami
K
K
Osawa
T
T
Toyoshima
S
S
D000116:Acetylgalactosamine / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001212:Asialoglycoproteins; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004926:Escherichia coli; D005260:Female; D005690:Galactose / Q000494:pharmacology; D015870:Gene Expression / Q000235:genetics; D037102:Lectins / Q000235:genetics*; D037181:Lectins, C-Type; D008264:Macrophages / Q000276:immunology*; D008565:Membrane Proteins; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface
D001212:Asialoglycoproteins; D002352:Carrier Proteins; C064720:Clec10a protein, mouse; C023339:Clec10a protein, rat; D037102:Lectins; D037181:Lectins, C-Type; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D000116:Acetylgalactosamine; D005690:Galactose