Fig 3.

(A and B) NPM mutant expression. (A) Diagram of Flag-NPM constructs cloned into lentiviral vectors. The diagram indicates key sites that regulate intracellular NPM localization. Deletion of the NLS prevents nuclear NPM entry, and deletion of the NES prevents NPM from exiting nuclei. A single-amino-acid substitution at lysine 263 (K²⁶³R) prevents NPM sumoylation, which is required for nuclear NPM export. (B) Expression of wild-type NPM and mutants was confirmed by immunoblot analysis using an anti-Flag antibody.