Identification of novel Saccharomyces cerevisiae proteins with nuclear export activity: cell cycle-regulated transcription factor ace2p shows cell cycle-independent nucleocytoplasmic shuttling.
Nuclear export of proteins containing leucine-rich nuclear export signals (NESs) is mediated by the NES receptor CRM1/Crm1p. We have carried out a yeast two-hybrid screen with Crm1p as a bait. The Crm1p-interacting clones were subscreened for nuclear export activity in a visual assay utilizing the Crm1p-inhibitor leptomycin B (LMB). This ... approach identified three Saccharomyces cerevisiae proteins not previously known to have nuclear export activity. These proteins are the 5' RNA triphosphatase Ctl1p, the cell cycle-regulated transcription factor Ace2p, and a protein encoded by the previously uncharacterized open reading frame YDR499W. Mutagenesis analysis show that YDR499Wp contains an NES that conforms to the consensus sequence for leucine-rich NESs. Mutagenesis of Ctl1p and Ace2p were unable to identify specific NES residues. However, a 29-amino-acid region of Ace2p, rich in hydrophobic residues, contains nuclear export activity. Ace2p accumulates in the nucleus at the end of mitosis and activates early-G(1)-specific genes. We now provide evidence that Ace2p is nuclear not only in late M-early G(1) but also during other stages of the cell cycle. This feature of Ace2p localization explains its ability to activate genes such as CUP1, which are not expressed in a cell cycle-dependent manner.
Mesh Terms:
Active Transport, Cell Nucleus, Amino Acid Sequence, Carrier Proteins, Cell Cycle, Cell Nucleus, Cytoplasm, DNA-Binding Proteins, Fatty Acids, Unsaturated, G1 Phase, Glutathione Transferase, Membrane Transport Proteins, Microscopy, Fluorescence, Mitosis, Molecular Sequence Data, Mutagenesis, Site-Directed, Open Reading Frames, Plasmids, Protein Binding, Protein Structure, Tertiary, Recombinant Fusion Proteins, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Sequence Homology, Amino Acid, Time Factors, Transcription Factors, Two-Hybrid System Techniques
Active Transport, Cell Nucleus, Amino Acid Sequence, Carrier Proteins, Cell Cycle, Cell Nucleus, Cytoplasm, DNA-Binding Proteins, Fatty Acids, Unsaturated, G1 Phase, Glutathione Transferase, Membrane Transport Proteins, Microscopy, Fluorescence, Mitosis, Molecular Sequence Data, Mutagenesis, Site-Directed, Open Reading Frames, Plasmids, Protein Binding, Protein Structure, Tertiary, Recombinant Fusion Proteins, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Sequence Homology, Amino Acid, Time Factors, Transcription Factors, Two-Hybrid System Techniques
Mol. Cell. Biol.
Date: Nov. 01, 2000
PubMed ID: 11027275
View in: Pubmed Google Scholar
Download Curated Data For This Publication
15041
Switch View:
- Interactions 37