(A) EMSA analysis of K562 nuclear proteins bound to DM2 oligomers in the presence of NCAM and mutant NCAM cold competitor oligomers. [γ-³²P]dATP-labeled DM2 oligomers were incubated with K562 nuclear extracts in the presence of a 100-fold molar excess of cold DM2 oligomers (lane 3), NCAM oligomers (lane 4), and mutant NCAM oligomers (lane 5). Lane 2, K562 nuclear extracts with no added competitor (No comp.). The DM2 probe was run without any nuclear extracts in lane 1 (DM2 probe). (B) Supershift EMSA analysis of K562 nuclear proteins bound to DM2 oligomers in the presence of an anti-CDP/cut antibody. In the left panel, [γ-³²P]dATP-labeled DM2 oligomers were complexed with nuclear proteins from K562 cells (lane 2) and the DNA-protein complexes exposed either to preimmune serum (lane 3) or to anti-CDP/cut antibody (lane 4). In the right panel, NCAM oligomers were labeled with [γ-³²P]dATP and allowed to bind to nuclear proteins from K562 nuclear extracts. The resulting protein-DNA complexes were exposed either to preimmune serum (lane 6) or to anti-CDP/cut antibody (lane 7). Lane 1, DM2 oligomers without nuclear extract.