GFP-Nup43 and GFP3-Sec13 coimmunoprecipitate with myc6-Nup37 and the other constituents of the Nup107-160 complex. Immunoprecipitation using anti-GFP antibodies of soluble extracts from HeLa cells coexpressing GFP-Nup35, GFP-Nup43, or GFP3-Sec13, and myc6-Nup37. Equivalent amounts of total extracts (T) and immune supernatants (S) and tenfold equivalents of the immune pellets (P) were analyzed by immunoblot by using anti-GFP, anti-myc (that recognizes the myc6-Nup37 fusion), Nup85, Nup160, Nup133, Nup96, Nup107, Nup85, or Sec31 antibodies. Arrowheads indicate the position of the GFP fusions. Molecular mass markers on the left are in kilodlatons.