Shift syndecan-2 from RACK1 to caveolin-2 upon transformation with oncogenic ras.
Syndecan-2 was found to detach from RACK1 and associate with caveolin-2 and Ras in cells transformed with oncogenic ras. Most of syndecan-2 from transformed cells was revealed with negligible phosphorylations at tyrosine residues. We experimented with HeLa cells transfected with plasmids encoding syndecan-2 and its mutants (syndecan-2(Y180F), syndecan-2(Y192F), and syndecan-2(Y180,192F)) to provide evidences that PY180 of syndecan-2 is a binding site for RACK1 and is deprived in cells transfected with oncogenic ras. However, in HeLa cells transfected with syndecan-2(Y180F), RACK1 was found to sustain its reactions with syndecan-2 independent of phosphorylation. The finding of syndecan-2 reactive with caveolin-2/Ras suggests the molecular complex most likely to obstruct RACK1 for functional attachment at syndecan-2, as revealed in cells transfected with oncogenic ras. We provided evidences to reinforce the view that molecular rearrangements upon transformation are specific and interesting.
Huang
Jin-Wen
JW
Institute of Zoology, National Taiwan University, Taipei, Taiwan.
Chuang
Nin-Nin
NN
D000818:Animals; D001665:Binding Sites; D051243:Caveolin 2 / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D015689:Oncogene Protein p21(ras) / Q000235:genetics / Q000378:metabolism*; D019000:Phosphotyrosine / Q000378:metabolism; D011485:Protein Binding; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D053669:Syndecan-2 / Q000235:genetics / Q000378:metabolism*
D051243:Caveolin 2; D009363:Neoplasm Proteins; C419368:RACK1 protein, human; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D053669:Syndecan-2; D019000:Phosphotyrosine; D019204:GTP-Binding Proteins; D015689:Oncogene Protein p21(ras)