Functional Links between Basket and Other Lipid-Interacting Nups
(A) Genetic interaction analysis. Double mutant strains harboring a wild-type NUP1 cover plasmid (URA marker) were co-transformed with the indicated NUP1 plasmids (HIS marker). Growth was followed on SDC-His (loading control) and on SDC+5-fluoroorotic acid (5-FOA) plates to shuffle out the URA cover plasmid. Cells were spotted in 10-fold serial dilutions and incubated for 2 (SDC-His) or 3 days (5-FOA) at 30°C.
(B and C) A nup60Δnup1Δ mutant strain harboring a wild-type NUP1 cover plasmid (URA marker) was co-transformed with different NUP1 (HIS marker) and NUP60 plasmids (LEU marker) to yield the indicated genotypes. Growth was followed on SDC-His-Leu (loading control) and on 5-FOA plates to shuffle out the URA cover plasmid.
(D) Genetic interaction analysis of the nup1Δ1-32 (HIS plasmid) / nup60Δ1-47 (LEU plasmid) mutant with the indicated Nups. Cells also contain a wild-type NUP1 cover plasmid (URA marker), which was shuffled out on 5-FOA plates (30°C).
(E) Model depicting the hypothetical changes of pore membrane and NPC structure in cells lacking INM bending by Nup1/Nup60 (AH and HR). Destabilization of cytoplasmic Nups (Nup159/Nup82) and basket Nups (Nup1/Nup60/Mlps) is indicated by light colors. Membrane destabilization may result in sealed NPCs according to a mechanism proposed by (Wente and Blobel, 1993). Known lipid-interacting parts of the NPC are indicated in dark blue. For simplicity, only one bipartite N terminus representing Nup1/Nup60 is shown.