Identification and characterization of the nuclear import and export signals of the mammalian Ste20-like protein kinase 3.
Mst3, a human Ste20-like protein kinase, has been recently demonstrated to undergo a caspase-mediated cleavage during apoptosis. The proteolytic cleavage of the C-terminus of Mst3 caused nuclear translocation of its kinase domain. This work provides evidence that Mst3 may contain a bipartite-like nuclear localization sequence (NLS) at the C-terminus of its kinase domain (residues 278-292). The removal of NLS from the kinase domain of Mst3 led to the cytoplasmic accumulation of EGFP-Mst3(Delta277). The presence of nuclear exporting signals in the Mst3 was also demonstrated by leptomycin B-treatment and serial deletion of the C-terminal regulatory domain of Mst3. A nuclear export signal was also postulated to be in the regions of amino acids 335-386. In conclusion, Mst3 contains both NLS and NES signals, which may cooperate to control the subcellular distribution of Mst3.
Department of Biological Science and Technology, National Chiao Tung University, 75 Po-Ai Street, Hsinchu 300, Taiwan, ROC.
Wan-Shu
WS
Lee
Chiung-Yueh
CY
Hsu
Pei-Ling
PL
Wang
Chi-Ying Fred
CY
Huang
Chia-Hua
CH
Chang
Chiun-Jye
CJ
Yuan
D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000378:metabolism; D008322:Mammals; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000099317:Hippo Kinases
D017931:DNA Primers; D005231:Fatty Acids, Unsaturated; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D010446:Peptide Fragments; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins; C430908:STK26 protein, human; D000099317:Hippo Kinases; C038753:leptomycin B