TY - JOUR
T1 - Proteasome-dependent truncation of the negative heterochromatin regulator Epe1 mediates antifungal resistance
AU - Yaseen, Imtiyaz
AU - White, Sharon
AU - Torres-Garcia, Sito
AU - Spanos, Christos
AU - Lafos, Marcel
AU - Gaberdiel, Elisabeth
AU - Yeboah, Rebecca
AU - El Karoui, Meriem
AU - Rappsilber, Juri
AU - Pidoux, Alison
AU - Allshire, Robin
N1 - Funding Information:
We thank D. Kelly (WCB, Edinburgh) for microscopy and instrumentation support; members of the Allshire Lab for valuable discussions and input; T. Urano for the 5.1.1 (H3K9me2) antibody; A. Fellas for GFP expressing and clr4∆ strains; K. Gull for α-tubulin antibody; K. Sawin for Mto2 antibody; A. L. Marston for the Sgo1-GFP S. cerevisiae strain; J. Svejstrup for provision of the MultiDsk2 expression construct; M. D. Wilson for comments on the manuscript; and colleagues at WCB for support and encouragement during a difficult 2020–21. This research was supported by award of an EMBO Long Term Fellowship to I. Y. (EMBO ALTF 130–2018), Darwin Trust of Edinburgh PhD studentships to S. T.-G. and R. Y., a Wellcome 4 Year iCM program PhD studentship to E. G. (218470), a Wellcome Instrument grant to J. R. (108504), a Wellcome Investigator award to M. E. K. (205008), a Wellcome Principal Research Fellowship to R. C. A. (200885; 224358) and core funding for the Wellcome Centre for Cell Biology (203149). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. For the purpose of Open Access, the author has applied a CC-BY public copyright licence to any author-accepted manuscript version arising from this submission.
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Nature America, Inc.
PY - 2022/7/25
Y1 - 2022/7/25
N2 - Epe1 histone demethylase restricts H3K9-methylation-dependent heterochromatin, preventing it from spreading over, and silencing, gene-containing regions in fission yeast. External stress induces an adaptive response allowing heterochromatin island formation that confers resistance on surviving wild-type lineages. Here we investigate the mechanism by which Epe1 is regulated in response to stress. Exposure to caffeine or antifungals results in Epe1 ubiquitylation and proteasome-dependent removal of the N-terminal 150 residues from Epe1, generating truncated Epe1 (tEpe1) which accumulates in the cytoplasm. Constitutive tEpe1 expression increases H3K9 methylation over several chromosomal regions, reducing expression of underlying genes and enhancing resistance. Reciprocally, constitutive non-cleavable Epe1 expression decreases resistance. tEpe1-mediated resistance requires a functional JmjC demethylase domain. Moreover, caffeine-induced Epe1-to-tEpe1 cleavage is dependent on an intact cell integrity MAP kinase stress signaling pathway, mutations in which alter resistance. Thus, environmental changes elicit a mechanism that curtails the function of this key epigenetic modifier, allowing heterochromatin to reprogram gene expression, thereby bestowing resistance to some cells within a population. H3K9me-heterochromatin components are conserved in human and crop-plant fungal pathogens for which a limited number of antifungals exist. Our findings reveal how transient heterochromatin-dependent antifungal resistant epimutations develop and thus inform on how they might be countered.
AB - Epe1 histone demethylase restricts H3K9-methylation-dependent heterochromatin, preventing it from spreading over, and silencing, gene-containing regions in fission yeast. External stress induces an adaptive response allowing heterochromatin island formation that confers resistance on surviving wild-type lineages. Here we investigate the mechanism by which Epe1 is regulated in response to stress. Exposure to caffeine or antifungals results in Epe1 ubiquitylation and proteasome-dependent removal of the N-terminal 150 residues from Epe1, generating truncated Epe1 (tEpe1) which accumulates in the cytoplasm. Constitutive tEpe1 expression increases H3K9 methylation over several chromosomal regions, reducing expression of underlying genes and enhancing resistance. Reciprocally, constitutive non-cleavable Epe1 expression decreases resistance. tEpe1-mediated resistance requires a functional JmjC demethylase domain. Moreover, caffeine-induced Epe1-to-tEpe1 cleavage is dependent on an intact cell integrity MAP kinase stress signaling pathway, mutations in which alter resistance. Thus, environmental changes elicit a mechanism that curtails the function of this key epigenetic modifier, allowing heterochromatin to reprogram gene expression, thereby bestowing resistance to some cells within a population. H3K9me-heterochromatin components are conserved in human and crop-plant fungal pathogens for which a limited number of antifungals exist. Our findings reveal how transient heterochromatin-dependent antifungal resistant epimutations develop and thus inform on how they might be countered.
U2 - 10.1038/s41594-022-00801-y
DO - 10.1038/s41594-022-00801-y
M3 - Article
C2 - 35879419
SN - 1545-9993
VL - 29
SP - 745
EP - 758
JO - Nature Structural & Molecular Biology
JF - Nature Structural & Molecular Biology
IS - 8
ER -