Identification of nuclear import and export signals within the structure of the zinc finger protein TIS11.
TIS11, a member of the CCCH zinc finger protein family, functions as a positive transcriptional regulator. TIS11 was localized in both the cytoplasm and nucleus when transiently expressed in COS-7 cells. Upon treatment with leptomycin B, a specific inhibitor of the nuclear export receptor CRM1, a marked nuclear accumulation of TIS11 was observed, indicating that TIS11 shuttles between the nucleus and the cytoplasm. By deletion studies using a green fluorescent protein fusion system, we have mapped a functional nuclear localization signal (NLS) to a region containing two tandem repeats of the zinc finger motif of TIS11. A site-directed mutagenesis analysis of TIS11 NLS has revealed the critical importance of two arginine residues (Arg127 and Arg131 in the rat TIS11). Furthermore, we demonstrated that the N-terminal Leu-rich region of TIS11 serves as an LMB-sensitive nuclear export signal (NES), indicating that TIS11 follows a CRM1-mediated export pathway. These results suggest that TIS11 is subject to constant nucleocytoplasmic shuttling due to its NLS and NES.
Murata
Tomiyasu
T
Department of Analytical Neurobiology, Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468-8503, Japan.
Yoshino
Yumi
Y
Morita
Noriyoshi
N
Kaneda
Norio
N
D021581:Active Transport, Cell Nucleus; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D001120:Arginine / Q000737:chemistry; D001483:Base Sequence; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D017353:Gene Deletion; D049452:Green Fluorescent Proteins; D017874:Immediate-Early Proteins / Q000737:chemistry* / Q000378:metabolism*; D028884:Karyopherins / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D051816:Tristetraprolin; D016335:Zinc Fingers; D000097606:Exportin 1 Protein
D000903:Antibiotics, Antineoplastic; D001120:Arginine; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D005231:Fatty Acids, Unsaturated; D049452:Green Fluorescent Proteins; D017874:Immediate-Early Proteins; D028884:Karyopherins; D008164:Luminescent Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D051816:Tristetraprolin; D000097606:Exportin 1 Protein; C497554:Zfp36 protein, rat; C038753:leptomycin B