Vesicular-integral membrane protein, VIP36, recognizes high-mannose type glycans containing alpha1-->2 mannosyl residues in MDCK cells.
The 36 kDa vesicular-integral membrane protein, VIP36, has been originally isolated from MDCK cells as a component of glycolipid-enriched detergent-insoluble complexes containing apical marker proteins, and its luminal domain shows homology to leguminous plant lectins and ERGIC-53. As the first step to identify the functional role of VIP36, the carbohydrate binding specificity of VIP36 was investigated using a fusion protein of glutathione- S -transferase and luminal domain of VIP36 (Vip36). It was found that VIP36 recognizes high-mannose type glycans containing alpha1-->2 Man residues and alpha-amino substituted asparagine. The binding of Vip36 to high-mannose type glycans was independent of Ca(2+)and theoptimal condition was pH 6.0 at 37 degrees C. The concentration at which half inhibition of the binding by Man(7-9).GlcNAc(2). N Ac. Asn occurred was 1.0 x 10(-9)M. The association constant between Man(7-9).GlcNAc(2)in porcine thyroglobulin and immobilized Vip36 was 2.1 x 10(8)M(-1)as determined by means of a biosensor based on surface plasmon resonance. These results indicate that VIP36 functions as an intracellular lectin recognizing glycoproteins which possess high-mannose type glycans, (Manalpha1-->2)(2-4).Man(5). GlcNAc(2).
Department of Biochemistry, Sasaki Institute, 2-2 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
S
S
Hara-Kuge
T
T
Ohkura
A
A
Seko
K
K
Yamashita
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002352:Carrier Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D002460:Cell Line; D004285:Dogs; D005982:Glutathione Transferase / Q000096:biosynthesis; D006001:Glycoconjugates / Q000737:chemistry / Q000302:isolation & purification; D007668:Kidney; D037102:Lectins; D008358:Mannose / Q000032:analysis; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013462:Sulfur Radioisotopes; D013552:Swine; D013954:Thyroglobulin / Q000737:chemistry; D014162:Transfection
D002352:Carrier Proteins; D006001:Glycoconjugates; D037102:Lectins; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D011134:Polysaccharides; D011993:Recombinant Fusion Proteins; D013462:Sulfur Radioisotopes; C490134:VIP36 protein, Canis familiaris; D013954:Thyroglobulin; D005982:Glutathione Transferase; D008358:Mannose