Figure 2.

IRT1 Ubiquitination in the idf1-1 Mutant.

(A) IRT1 and its ubiquitin conjugates were detected by immunoblot with IRT1-U antibody on protein extracts from the roots of the wild type (Wt) and idf1-1 after Fe deficiency for 3 d. Predicted IRT1-ubquitin conjugates are indicated. Coomassie blue stain (CB) indicates equal loading.

(B) Immunoprecipitation was performed on 3-d Fe-deficient root protein extracts with anti-IRT1 (IRT1-U) antibody and subjected to immunoblot with anti-IRT1 (IRT1-U) antibody or the anti-ubiquitin (P4D1) antibody. Heavy chain (HC) and light chain (LC) of IgG are indicated. The signal of IRT1 with four ubiquitin molecules (IRT1-Ub₄) was not observed in the idf1-1 and irt1 mutants.