Figure 8.

Importin β forms a high-molecular-weight complex with both ELYS and Nup107-160. (A) ELYS-enriched fractions eluted from a Q-Sepharose column, as in Figure 5, were pooled and loaded on a Superose-6 column. One-half of the sample was preincubated with 10 μM Xenopus importin β before gel filtration (+XImp β rows). Samples eluted from these two gel filtration runs (−/+β) were analyzed by immunoblotting. Note that the addition of excess importin β does not shift ELYS to lower molecular weight fractions. (B) Two Superose-6 gel filtration runs (−/+ importin β) were performed as in A. Fractions 5–8 eluted from each column were pooled together and subjected to immunoprecipitation with anti-ELYS or anti-Nup107 antibodies. Immunoblotting confirms the existence of a high-molecular-weight complex containing ELYS, Nup107-160, and importin β.