... significantlydownregulated in imp a5) ⁄ )mice, by 20%. Thesefindings indicate that importin a5 is prominentlyinvolved in gene regulation by ER and its cofactors.On the other hand, the protein levels in ... upregulated in the brain,suggesting that the counter-regulation of another im-portin a isoform may compensate for the lack of asingle isoform in vivo in mammals [21]. Therefore, todetermine ... import. On the otherhand, the importin a family generally binds to both the nuclear import cargo and importin b, indicatingthat importin a functions as an adaptor between the cargo proteins and importin...