N-acetylglucosaminyltransferase III antagonizes the effect of N-acetylglucosaminyltransferase V on alpha3beta1 integrin-mediated cell migration.
N-acetylglucosaminyltransferase V (GnT-V) catalyzes the addition of beta1,6-GlcNAc branching of N-glycans, which contributes to metastasis. N-acetylglucosaminyltransferase III (GnT-III) catalyzes the formation of a bisecting GlcNAc structure in N-glycans, resulting in the suppression of metastasis. It has long been hypothesized that the suppression of GnT-V product formation by the action of GnT-III would also exist in vivo, which will consequently lead to the inhibition of biological functions of GnT-V. To test this, we draw a comparison among MKN45 cells, which were transfected with GnT-III, GnT-V, or both, respectively. We found that alpha3beta1 integrin-mediated cell migration on laminin 5 was greatly enhanced in the case of GnT-V transfectant. This enhanced cell migration was significantly blocked after the introduction of GnT-III. Consistently, an increase in bisected GlcNAc but a decrease in beta1,6-GlcNAc-branched N-glycans on integrin alpha3 subunit was observed in the double transfectants of GnT-III and GnT-V. Conversely, GnT-III knockdown resulted in increased migration on laminin 5, concomitant with an increase in beta1,6-GlcNAc-branched N-glycans on the alpha3 subunit in CHP134 cells, a human neuroblastoma cell line. Therefore, in this study, the priority of GnT-III for the modification of the alpha3 subunit may be an explanation for why GnT-III inhibits GnT-V-induced cell migration. Taken together, our results demonstrate for the first time that GnT-III and GnT-V can competitively modify the same target glycoprotein and furthermore positively or negatively regulate its biological functions.
Zhao
Yanyang
Y
Departments of Biochemistry and Glycotherapeutics, Osaka University Graduate School of Medicine, B1, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Nakagawa
Takatoshi
T
Itoh
Satsuki
S
Inamori
Kei-ichiro
K
Isaji
Tomoya
T
Kariya
Yoshinobu
Y
Kondo
Akihiro
A
Miyoshi
Eiji
E
Miyazaki
Kaoru
K
Kawasaki
Nana
N
Taniguchi
Naoyuki
N
Gu
Jianguo
J
D045744:Cell Line, Tumor; D002465:Cell Movement; D004847:Epithelial Cells / Q000502:physiology; D006801:Humans; D039201:Integrin alpha3beta1 / Q000378:metabolism*; D039081:Integrin alpha5beta1 / Q000378:metabolism*; D008954:Models, Biological; D017351:N-Acetylglucosaminyltransferases / Q000037:antagonists & inhibitors*; D034741:RNA, Small Interfering / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology; D014162:Transfection
D039201:Integrin alpha3beta1; D039081:Integrin alpha5beta1; D034741:RNA, Small Interfering; D017351:N-Acetylglucosaminyltransferases; C054599:beta-1,4-mannosyl-glycoprotein beta-1,4-N-acetylglucosaminyltransferase