The Ran GTPase activating protein RanGAP1 plays an essential role in nuclear transport by stimulating RanGTP hydrolysis in the cytoplasmic compartment. In mammalian cells, unmodified RanGAP1 is predominantly cytoplasmic, whereas modification by small ubiquitin-related modifier protein (SUMO) targets RanGAP1 to the cytoplasmic filaments of nuclear pore complex (NPC). Although RanGAP1 contains ni...

The cyclin-dependent kinase Cdc28p associates with the cyclin Clb2p to induce mitosis in the yeast Saccharomyces cerevisiae. Several cell cycle regulatory proteins have been shown to require specific nuclear transport events to exert their regulatory functions. Therefore, we investigated the subcellular localization of wild-type Clb2p and several mutant versions of the protein using green fluor...

The enzyme 5-lipoxygenase (5-LO) initiates the synthesis of leukotrienes from arachidonic acid. In resting cells, 5-LO can accumulate in either the cytoplasm or the nucleoplasm and, upon cell stimulation, translocates to membranes to initiate leukotriene synthesis. Here, we used mutants of 5-LO with altered subcellular localization to assess the role that nuclear positioning plays in determinin...

The pro-inflammatory cytokine Interleukin-1α (IL-1α) has recently emerged as a susceptibility marker for a wide array of inflammatory diseases associated with oxidative stress including Alzheimer's, arthritis, atherosclerosis, diabetes and cancer. In the present study, we establish that expression and nuclear localization of IL-1α are redox-dependent. Shifts in steady-state H2O2 concentrations ...

When activated by high NaCl, tonicity-responsive enhancer-binding protein/osmotic response element-binding protein (TonEBP/OREBP) increases transcription of osmoprotective genes. High NaCl activates TonEBP/OREBP by increasing its phosphorylation, nuclear localization, and transactivating activity. In HEK293 cells, mass spectrometry shows phosphorylation of TonEBP/OREBP-S120, -S134, -T135, and -...

Recent ultrastructural studies revealed that a structure similar to the vertebrate nuclear lamina exists in the nuclei of higher plants. However, plant genomes lack genes for lamins and intermediate-type filament proteins, and this suggests that plant-specific nuclear coiled-coil proteins make up the lamina-like structure in plants. NMCP1 is a protein, first identified in Daucus carota cells, t...

The nucleoprotein (NP) of influenza A virus is transported into the nucleus via the classical importin α/β pathway, and proceeds via nuclear localization signals (NLSs) recognized by importin α molecules. Although NP binds to importin α isoforms Rch1, Qip1 and NPI-1, the role of each individual isoform during the nuclear transport of NP and replication of the influenza virus remains unknown. In...

Fanconi anemia (FA) is an autosomal recessive disease characterized by a variety of congenital abnormalities. Cells from FA patients show chromosomal instability and are hypersensitive to DNA cross-linking agents, though the basic cellular defect in FA is not known. The FANCA gene encodes a protein with an Mr of 162 kDa and with unknown function. The cellular localization of the FANCA protein h...

Arabidopsis thaliana UV RESISTANCE LOCUS8 (UVR8) is a UV-B-specific signaling component that binds to chromatin and regulates UV protection by orchestrating expression of a range of genes. Here, we studied how UV-B regulates UVR8. We show that UV-B stimulates the nuclear accumulation of both a green fluorescent protein (GFP)-UVR8 fusion and native UVR8. Nuclear accumulation leads to UV-B induct...