Up‐regulation of nuclear protein import by nuclear localization signal sequences in living cells

FEBS Letters

Tachibana, Taro¹  Yoneda, Yoshihiro¹  Hieda, Miki¹ 

[1] Department of Anatomy and Cell Biology, Osaka University Medical School, 2-2, Yamada-oka, Suita, Osaka 565-0871, Japan

关键词: Nuclear protein import;    Nuclear localization signal;    Phosphorylation;    NLS;    nuclear localization signal;    CBP;    Cap binding protein;    PTAC;    nuclear pore-targeting complex;    NTF2;    nuclear transport factor 2;    BSA;    bovine serum albumin;    hsc70;    70-kDa heat-shock cognate protein;    RCC1;    regulator of chromosome condensation;    RanGAP1;    Ran GTPase activating protein 1;    RanBP;    Ran binding protein;   

DOI  :  10.1016/S0014-5793(98)01664-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Using an in vivo assay system, nuclear import ability in individual cells was determined by examining the nuclear import rate. It was found that when a small (not excess) amount of SV40 T-NLS peptides was co-injected, the nuclear import rate of SV40 T-NLS-containing substrates apparently increased. This up-regulation was reproduced by the co-injection of peptides containing bipartite type NLS of CBP80, but not mutated non-functional NLS peptides, which suggests that these phenomena are specific for functional NLSs. It was further shown that although, in growth-arrested cells, the nuclear import rate was down-regulated compared to growing cells, the elevation of the functional import rate by co-injected NLS peptides reached the same level as in proliferating cells. This up-regulation was abolished by the addition of a protein kinase inhibitor, staurosporine. These results suggest that although potential nuclear import ability does not vary in each cell, the rate of nuclear import may be controlled by the amount of karyophilic proteins, which need to be carried into the nucleus from the cytoplasm, possibly via an NLS-dependent phosphorylation reaction.

【 授权许可】

Unknown