Regulation on the expression and N-glycosylation of integrins by N-acetylglucosaminyltransferase V.
The expressions of integrin alpha5, beta1, and alpha6 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 beta1>alpha5>alpha6. Transfection of sense GnT-V up-regulated alpha5 and alpha6, but not beta1 subunit, while antisense GnT-V down-regulated alpha5 and beta1, but not alpha6. The alterations of surface integrin subunits were quite compatible with the changes of their mRNAs. Using enzyme-labeled lectin analysis, it was shown that alpha5 subunit contained only C(2)C(2) biantennary N-glycan, which was not regulated by sense and antisense GnT-V. In contrast, beta1 subunit contained both biantennary and tri-/tetra-antennary N-glycans with GlcNAcbeta1,6Manalpha1,6-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 beta1 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.
Guo
Peng
P
Key Laboratory of Glycoconjugate Research, Ministry of Health, Department of Biochemistry, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Zhang
Ying
Y
Zhao
Jia-hong
JH
Wang
Li-ying
LY
Guo
Hua-bei
HB
Zhang
Xia-ying
XY
Chen
Hui-li
HL
D002460:Cell Line; D016373:DNA, Antisense / Q000235:genetics; D005786:Gene Expression Regulation; D006031:Glycosylation; D006801:Humans; D039482:Integrin alpha5 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D039503:Integrin alpha6 / Q000235:genetics / Q000378:metabolism; D019012:Integrin beta1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016023:Integrins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics / Q000378:metabolism*; D011134:Polysaccharides / Q000032:analysis; D021122:Protein Subunits; D012333:RNA, Messenger / Q000378:metabolism; D014162:Transfection
D016373:DNA, Antisense; D039482:Integrin alpha5; D039503:Integrin alpha6; D019012:Integrin beta1; D016023:Integrins; D011134:Polysaccharides; D021122:Protein Subunits; D012333:RNA, Messenger; D017351:N-Acetylglucosaminyltransferases; C052254:alpha-1,6-mannosylglycoprotein beta 1,6-N-acetylglucosaminyltransferase