Regulation on the expression and N-glycosylation of integrins by N-acetylglucosaminyltransferase V

• Published in: Biochemical and biophysical research communications 2003-10, Vol.310 (2), p.619-626
• Main Authors: Guo, Peng, Zhang, Ying, Zhao, Jia-hong, Wang, Li-ying, Guo, Hua-bei, Zhang, Xia-ying, Chen, Hui-li
• Format: Article
• Language: English
• Subjects: Cell Line; DNA, Antisense - genetics; Gene Expression Regulation; Glycosylation; Human hepatocarcinoma cells; Humans; Integrin; Integrin alpha5 - chemistry; Integrin alpha5 - genetics; Integrin alpha5 - metabolism; Integrin alpha6 - genetics; Integrin alpha6 - metabolism; Integrin beta1 - chemistry; Integrin beta1 - genetics; Integrin beta1 - metabolism; Integrins - chemistry; Integrins - genetics; Integrins - metabolism; N-Acetylglucosaminyltransferase V; N-Acetylglucosaminyltransferases - genetics; N-Acetylglucosaminyltransferases - metabolism; N-Glycan; Polysaccharides - analysis; Protein Subunits; RNA, Messenger - metabolism; Transfection
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2003.09.059

The expressions of integrin α5, β1, and α6 were studied in H7721 cells by means of flow cytometric and RT-PCR method after transfected with sense and antisense cDNA of N-acetylglucosaminyltransferase V (GnT-V). The transfected cells were characterized by Northern blot. It was found that the order of expression from high to low was β1>α5>α6. Transfection of sense GnT-V up-regulated α5 and α6, but not β1 subunit, while antisense GnT-V down-regulated α5 and β1, but not α6. The alterations of surface integrin subunits were quite compatible with the changes of their mRNAs. Using enzyme-labeled lectin analysis, it was shown that α5 subunit contained only C 2C 2 biantennary N-glycan, which was not regulated by sense and antisense GnT-V. In contrast, β1 subunit contained both biantennary and tri-/tetra-antennary N-glycans with GlcNAcβ1,6Manα1,6-branch, and the latter was up- and down-regulated by the sense and antisense GnT-V, respectively. Therefore, the amount of biantennary N-glycans on β1 subunit, but not the integrin protein, was correlated to the cell adhesion to fibronectin and laminin, which was reduced and elevated in the sense and antisense GnT-V-transfected cells, respectively, as we previously reported.