Importin β3 mediates the nuclear import of human ribosomal protein L7 through its interaction with the multifaceted basic clusters of L7.
We show that importin β3 is essential for the nuclear import of L7. The import is mediated via the multifaceted basic amino acid clusters present in the NH(2)-region of L7, and is RanGTP-dependent. Using a (EGFP)(3) reporter system and a FRAP assay, the role the individual clusters play as a functional NLS has been characterized, and each cluster was found to exhibit a different rate of real time nuclear uptake. We assume that having such a multiple NLS may provide L7 with preferential nuclear uptake.
Chou
Chang-Wei
CW
Institute of Genome Sciences, School of Life Sciences, National Yang-Ming University, Shih-Pai, Taipei, Taiwan, ROC.
Tai
Lin-Ru
LR
Kirby
Ralph
R
Lee
I-Fang
IF
Lin
Alan
A
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055785:Gene Knockdown Techniques; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D028961:beta Karyopherins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020931:ran GTP-Binding Protein / Q000378:metabolism
D002352:Carrier Proteins; C107940:IPO5 protein, human; D050505:Mutant Proteins; C053634:RPL7 protein, human; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; D028961:beta Karyopherins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D020931:ran GTP-Binding Protein