FIG. 6.

Gas6 interferes with β-catenin protein stability in C57MG cells. (A) Replicate cultures of control cells (−) or C57MG cells stimulated overnight with Gas6 (+) were pulse labeled (0 h) with [³⁵S]methionine for 30 min and chased in the absence of the label for 1 and 2 h. At each time point, cellular extracts were prepared and immunoprecipitated with antibodies specific either to β-catenin (upper panel) or Axl RTK (lower panel). The immunocomplexes were analyzed by SDS-PAGE followed by fluorography. (B) Western blot analysis of β-catenin association. Confluent C57MG cells undergoing density-dependent inhibition were stimulated (Gas6) or not (−) for 30 min with 400 ng of Gas6/ml. After this time, equivalent amounts of protein extracts were immunoprecipitated with antibodies specific to either cadherins (IP:cad), α-catenin (IP αcat), or GSK3 (IP:GSK3). Immunocomplexes were resolved by SDS–10% PAGE and were blotted to nitrocellulose membranes. Western blotting was carried out with specific antibodies to β-catenin. The position of β-catenin is indicated by arrows.