SILAC-Tp (importin-alpha/beta +MA-5)

HeLa-S3 adherent cells were labeled with u-13C6 Lys and u-13C6 Arg and the cell membranes were permeabilized. Proteins in unlabeled HeLa-S3 nuclear extract depleted of all nuclear transport receptors (NTRs) were transported into the nuclei of the permeabilized cells (i) in the absence of any NTR, (ii) in the presence of importin-alpha and -beta, and (iii) in the presence of importin-alpha, -beta, and mitochonic acid-5 (MA-5). After the transport, the nuclear proteins were extracted and analyzed.