TY - JOUR
T1 - An RNAi-independent role of AP1-like stress response factor Pap1 in centromere and mating-type silencing in Schizosaccaromyces pombe
AU - Kumar, Ashok
AU - Nanda, Jagpreet Singh
AU - Saini, Sharanjot
AU - Singh, Jagmohan
N1 - Publisher Copyright:
© 2021, Indian Academy of Sciences.
PY - 2021/9
Y1 - 2021/9
N2 - Gene silencing in S. pombe occurs by heterochromatin formation at the centromere (cen), mating-type (mat) and telomere loci. It is mediated by silencing factors including Swi6, Clr1-4, Rhp6 and Polα. RNAi pathway also plays a role in establishment of silencing at the mat and cen loci. Recently, the stress response factors, Atf1 and Pcr1were shown to play an RNAi-independent role in silencing at the mat3 locus through a cis-acting Atf1-binding site located within the repression element REIII and recruitment of the silencing factors Clr3 and Clr6. Another cis-acting site, named repression element REII abutting the mat2 locus, also establishes heterochromatin structure through Clr5 and histone deacetylases but independently of H3-Lys9-methylation and RNAi. Here, we report the occurrence of binding sites for another oxidative response factor, the pombe AP1-like factor Pap1, at the mating-type, centromere and telomere loci. By genetic studies we show that these sites play a role in silencing at the outer repeats of centromeres as well as mating-type locus and this effect is mediated through Pap1 binding site and interaction with and recruitment of the HP1/Swi6. Importantly, pap1Δ cells display a silencing defect even in absence of the oxidative stress. Such a role of Pap1 in heterochromatin formation may be evolutionarily conserved.
AB - Gene silencing in S. pombe occurs by heterochromatin formation at the centromere (cen), mating-type (mat) and telomere loci. It is mediated by silencing factors including Swi6, Clr1-4, Rhp6 and Polα. RNAi pathway also plays a role in establishment of silencing at the mat and cen loci. Recently, the stress response factors, Atf1 and Pcr1were shown to play an RNAi-independent role in silencing at the mat3 locus through a cis-acting Atf1-binding site located within the repression element REIII and recruitment of the silencing factors Clr3 and Clr6. Another cis-acting site, named repression element REII abutting the mat2 locus, also establishes heterochromatin structure through Clr5 and histone deacetylases but independently of H3-Lys9-methylation and RNAi. Here, we report the occurrence of binding sites for another oxidative response factor, the pombe AP1-like factor Pap1, at the mating-type, centromere and telomere loci. By genetic studies we show that these sites play a role in silencing at the outer repeats of centromeres as well as mating-type locus and this effect is mediated through Pap1 binding site and interaction with and recruitment of the HP1/Swi6. Importantly, pap1Δ cells display a silencing defect even in absence of the oxidative stress. Such a role of Pap1 in heterochromatin formation may be evolutionarily conserved.
KW - Fission yeast
KW - Pap1
KW - heterochromatin
KW - mating-type loci
KW - oxidative stress
KW - silencing
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U2 - 10.1007/s12038-021-00199-7
DO - 10.1007/s12038-021-00199-7
M3 - Article
C2 - 34344846
AN - SCOPUS:85111510300
SN - 0250-5991
VL - 46
JO - Journal of Biosciences
JF - Journal of Biosciences
IS - 3
M1 - 74
ER -