Nup93 forms two distinct complexes. (A) Immunoprecipitations were performed from Xenopus egg cytosol with antibodies against Nup188 (two antibodies raised in different rabbits), Nup93, Nup205, Nup155, and Nup53 and, as a control, Nup98. The indicated proteins were identified by Western blotting with the respective antisera. 10% of starting material (input) was loaded on the left. (B) Quantitative immunoprecipitations were performed from limited amounts of Xenopus egg cytosol with antibodies against Nup188, Nup93, and Nup205 and, as a control, Nup98. Immunoprecipitates and unbound material as well as 10, 30, and 100% of the starting material (input) were analyzed by Western blotting. The Nup93 antibody also recognized a cross-reactivity (asterisk) in the starting and unbound material migrating slightly slower.