Genetic characterisation of hda1+, a putative fission yeast histone deacetylase gene

Abstract

hda1+ (histone deacetylase 1) is a fission yeast gene which is highly similar in sequence to known histone deacetylase genes in humans and budding yeast. We have investigated if this putative histone deacetylase contributes to transcriptional silencing in the fission yeast Schizosaccharomyces pombe. A precise deletion allele of the hda1+ open reading frame was created. Cells lacking the hda1+ gene are viable. However, genetic analysis reveals that cells without hda1 + display enhanced gene repression/silencing of marker genes, residing adjacent to telomeres, close to the silent mating-type loci and within centromere I. This phenotype is very similar to that recently reported for rpd3 mutants both in Drosophila and budding yeast. No defects in chromosome segregation or changes in telomere length were detected. Cells lacking the hda1+ gene display reduced sporulation. Growth of hda1 cells is partially inhibited by low concentrations of Trichostatin A (TSA), a known inhibitor of histone deacetylase enzymes. TSA treatment is also able to overcome the enhanced silencing found in heterochromatic regions of hda1 cells. These results indicate a genetic redundancy with respect to deacetylase genes and partially overlapping functions of these in fission yeast. The significance of these results is discussed in the light of recent discoveries from other eukaryotes.

Insights into the Role of Histone H3 and Histone H4 Core Modifiable Residues in Saccharomyces cerevisiae

“…This paradox can be reconciled by the fact that different proteins are required in the establishment of silencing at each of these loci, and perhaps K77 modification is important for this distinction. This observed effect at telomeres is consistent with findings that knockout of class I histone deacetylases, which presumably leads to increased acetylation of histones (and perhaps other proteins), paradoxically enhances silencing in several organisms (9,37,46).…”

Diminishing HDACs by drugs or mutations promotes normal or abnormal sister chromatid separation by affecting APC/C and adherin

“…As previously shown, S. pombe Class I HDAC mutant ⌬hos2 showed hypersensitivity to TSA (Kim, Y. et al, 1998;Olsson et al, 1998) Journal of Cell Science 121 (7) Δste9 N N N (Kitamura et al, 1998) Spindle checkpoint Mad2 Δmad2 N --- (Toyoda et al, 2002) Proteasome subunit Gordon et al, 1996) Separase hSeparase/Esp1 cut1-206 + + + (Hirano et al, 1986) …”

“…Fission yeast S. pombe has three Class I and II HDACs, Clr6, Clr3 and Hos2/Phd1/Hda1, that are sensitive to TSA and regulate histone acetylation levels in the genome, cooperating with Class III HDACs (Bjerling et al, 2002;Kim, Y. et al, 1998;Olsson et al, 1998;Wiren et al, 2005). Mutants of clr3 and clr6 were originally identified as defective in silencing of the mating type locus (Ekwall and Ruusala, 1994;Grewal et al, 1998;Thon et al, 1994).…”

A Novel Protein with Similarities to Rb Binding Protein 2 Compensates for Loss of Chk1 Function and Affects Histone Modification in Fission Yeast

“…Furthermore, the deletion mutants with reduced ability to coprecipitate HDAC activity failed to restore resistance to TSA, suggesting that these two properties are linked. There are several known HDAC in S. pombe, including Clr6, Clr3, and Hda1 (27,57). It is possible that the PHD fingers of Msc1 are required for recruitment of one or more of these enzymes to chromatin.…”

“…Therefore, we generated probes to several known HDAC, clr3 (6), hda1 (57), and clr6 (27), and to mst2 (SPAC17G8.13c) and esa1 (SPAC637.12c), two genes thought to encode HAT by virtue of their homology to such genes in other organisms. RNA was prepared from wild-type cells and cells lacking msc1 and probed by Northern blotting.…”