Olaf Nielsen

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Formins are involved in diverse aspects of morphogenesis, and share two regions of homology: FH1 and FH2. We describe a new formin homology region, FH3. FH3 is an amino-terminal domain that differs from the Rho binding site identified in Bni1p and p140mDia. The Schizosaccharomyces pombe formin Fus1 is required for conjugation, and is localized to the(More)
BACKGROUND Fission yeast cells undergo sexual differentiation in response to nitrogen starvation. In this process haploid M and P cells first mate to form diploid zygotes, which then enter meiosis and sporulate. Prior to mating, M and P cells communicate with diffusible mating pheromones that activate a signal transduction pathway in the opposite cell type.(More)
Telomeres share the ability to silence nearby transcription with heterochromatin, but the requirement of heterochromatin proteins for most telomere functions is unknown. The fission yeast Rik1 protein is required for heterochromatin formation at centromeres and the mating-type locus, as it recruits the Clr4 histone methyltransferase, whose modification of(More)
In fission yeast, the COP9 signalosome is required to activate ribonucleotide reductase for DNA synthesis. This is mediated via the ubiquitin ligase Pcu4, activation of which leads to degradation of the scaffold protein Spd1, which anchors the small ribonucleotide reductase subunit in the nucleus away from the large subunit in the cytoplasm.
Retrotransposons, the ancestors of retroviruses, have the potential for gene disruption and genomic takeover if not kept in check. Paradoxically, although host cells repress these elements by multiple mechanisms, they are transcribed and are even activated under stress conditions. Here, we describe a new mechanism of retrotransposon regulation through(More)
The protein called p97 in mammals and Cdc48 in budding and fission yeast is a homo-hexameric, ring-shaped, ubiquitin-dependent ATPase complex involved in a range of cellular functions, including protein degradation, vesicle fusion, DNA repair, and cell division. The cdc48+ gene is essential for viability in fission yeast, and point mutations in the human(More)
Ageing and cancer is often associated with altered T cell distributions and this phenomenon has been suggested to be the main driver in the development of immunosenescence. Memory phenotype PD-1+ CD4+ T cells accumulate with age and during leukemic development, and they might account for the attenuated T cell response in elderly or diseased individuals. The(More)
In yeasts, small intrinsically disordered proteins (IDPs) modulate ribonucleotide reductase (RNR) activity to ensure an optimal supply of dNTPs for DNA synthesis. The S. pombe Spd1 protein can directly inhibit the large RNR subunit (R1), import the small subunit (R2) into the nucleus and induce an architectural change in the R1-R2 holocomplex. Here, we(More)