The Filamin-A is a partner of Tc-mip, a new adapter protein involved in c-maf-dependent Th2 signaling pathway

Using a yeast two-hybrid screen, we identified Filamin-A as a binding partner of the new adapter protein c-mip (c-maf inducing protein) and it's splice variant Tc-mip (truncated c-maf inducing protein). We have previously shown that Tc-mip is involved in Th2 signaling pathway and cytoskeletal reorganization in patients with minimal change nephrotic syndrome (MCNS), the most frequent glomerular disease in children. We showed that Filamin-A and c-mip or Tc-mip co-immunoprecipitate from c-mip or Tc-mip Jurkat transfected cells using Antibodies directed against both types of proteins. In co-immunoprecipitate Jurkat cells, Filamin-A and c-mip were distributed evenly in the cytoplasm, whereas in Tc-mip-transfected Jurkat cells, Filamin-A was expressed in zones facing the cell contact. Moreover, we found that Filamin-A was upregulated in T lymphocytes of MCNS patients, as compared to normal subjects. These findings suggest that Filamin-A interacts with c-mip/Tc-mip in this new T-cell signaling pathway.