Figure 5.

NRAMP2 Complements the smf2∆ and mtm1∆ Yeast Mutants.

(A), (D), and (E) Growth tests of wild-type (BY4741) and mutant yeast strains smf1∆ (A), smf2∆ ([A] and [E]), mtm1∆ (D), and pmr1∆ (E) transformed with the pYPGE15 empty vector (E.V.) or the pYPGE15/NRAMP2 construct (NRAMP2). Fivefold serial dilutions were plated on SD-Ura supplemented or not (control) with the amount of EGTA indicated in (A) and (D) or 2 mM MnSO₄ (E) and incubated at 30°C for 3 d.

(A) NRAMP2 restores smf2∆ mutant tolerance to Mn deficiency.

(B) Mn content measured by MP-AES in yeast strains grown in liquid SD -URA for 24 h. Mean ± sd (n = 3). Asterisks indicate values significantly different from those of the wild type (Student’s t test, *P value < 0.01).

(C) In-gel SOD activity assay performed on proteins extracted from yeast strains grown as in (B).

(D) NRAMP2 restores mtm1∆ mutant tolerance to Mn deficiency.

(E) NRAMP2 fails to rescue pmr1∆ mutant sensitivity to excess Mn and does not reduce wild-type or smf2∆ tolerance to excess Mn.