Analysis of a histone H2A variant from fission yeast: evidence for a role in chromosome stability

1994 ◽  
Vol 245 (5) ◽  
pp. 628-635 ◽  
Author(s):  
A. M. Carr ◽  
S. M. Dorrington ◽  
J. Hindley ◽  
G. A. Phear ◽  
S. J. Aves ◽  
...  
2004 ◽  
Vol 24 (14) ◽  
pp. 6215-6230 ◽  
Author(s):  
Toru M. Nakamura ◽  
Li-Lin Du ◽  
Christophe Redon ◽  
Paul Russell

ABSTRACT Mammalian ATR and ATM checkpoint kinases modulate chromatin structures near DNA breaks by phosphorylating a serine residue in the carboxy-terminal tail SQE motif of histone H2AX. Histone H2A is similarly regulated in Saccharomyces cerevisiae. The phosphorylated forms of H2AX and H2A, known as γ-H2AX and γ-H2A, are thought to be important for DNA repair, although their evolutionarily conserved roles are unknown. Here, we investigate γ-H2A in the fission yeast Schizosaccharomyces pombe. We show that formation of γ-H2A redundantly requires the ATR/ATM-related kinases Rad3 and Tel1. Mutation of the SQE motif to AQE (H2A-AQE) in the two histone H2A genes caused sensitivity to a wide range of genotoxic agents, increased spontaneous DNA damage, and impaired checkpoint maintenance. The H2A-AQE mutations displayed a striking synergistic interaction with rad22Δ (Rad52 homolog) in ionizing radiation (IR) survival. These phenotypes correlated with defective phosphorylation of the checkpoint proteins Crb2 and Chk1 and a failure to recruit large amounts of Crb2 to damaged DNA. Surprisingly, the H2A-AQE mutations substantially suppressed the IR hypersensitivity of crb2Δ cells by a mechanism that required the RecQ-like DNA helicase Rqh1. We propose that γ-H2A modulates checkpoint and DNA repair through large-scale recruitment of Crb2 to damaged DNA. This function correlates with evidence that γ-H2AX regulates recruitment of several BRCA1 carboxyl terminus domain-containing proteins (NBS1, 53BP1, MDC1/NFBD1, and BRCA1) in mammals.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Takaharu G. Yamamoto ◽  
Da-Qiao Ding ◽  
Yuki Nagahama ◽  
Yuji Chikashige ◽  
Tokuko Haraguchi ◽  
...  

1985 ◽  
Vol 5 (11) ◽  
pp. 3261-3269 ◽  
Author(s):  
J Choe ◽  
T Schuster ◽  
M Grunstein

The histone H2A and H2B genes of the fission yeast Schizosaccharomyces pombe were cloned and sequenced. Southern blot and sequence analyses showed that, unlike other eucaryotes, Saccharomyces cerevisiae included, S. pombe has unequal numbers of these genes, containing two histone H2A genes (H2A-alpha and -beta) and only one H2B gene (H2B-alpha) per haploid genome. H2A- and H2B-alpha are adjacent to each other and are divergently transcribed. H2A-beta has no other histone gene in close proximity. Preceding both H2A-alpha and -beta is a highly conserved 19-base-pair sequence (5'-CATCAC/AAACCCTAACCCTG-3'). The H2A DNA sequences encode two histone H2A subtypes differing in amino acid sequence (three residues) and size (H2A-alpha, 131 residues; H2A-beta, 130 residues). H2B-alpha codes for a 125-amino-acid protein. Sequence evolution is extensive between S. pombe and S. cerevisiae and displays unique patterns of divergence. Certain N-terminal sequences normally divergent between eucaryotes are conserved between the two yeasts. In contrast, the normally conserved hydrophobic core of H2A is as divergent between the yeasts as between S. pombe and calf.


1985 ◽  
Vol 5 (11) ◽  
pp. 3261-3269
Author(s):  
J Choe ◽  
T Schuster ◽  
M Grunstein

The histone H2A and H2B genes of the fission yeast Schizosaccharomyces pombe were cloned and sequenced. Southern blot and sequence analyses showed that, unlike other eucaryotes, Saccharomyces cerevisiae included, S. pombe has unequal numbers of these genes, containing two histone H2A genes (H2A-alpha and -beta) and only one H2B gene (H2B-alpha) per haploid genome. H2A- and H2B-alpha are adjacent to each other and are divergently transcribed. H2A-beta has no other histone gene in close proximity. Preceding both H2A-alpha and -beta is a highly conserved 19-base-pair sequence (5'-CATCAC/AAACCCTAACCCTG-3'). The H2A DNA sequences encode two histone H2A subtypes differing in amino acid sequence (three residues) and size (H2A-alpha, 131 residues; H2A-beta, 130 residues). H2B-alpha codes for a 125-amino-acid protein. Sequence evolution is extensive between S. pombe and S. cerevisiae and displays unique patterns of divergence. Certain N-terminal sequences normally divergent between eucaryotes are conserved between the two yeasts. In contrast, the normally conserved hydrophobic core of H2A is as divergent between the yeasts as between S. pombe and calf.


Science ◽  
2009 ◽  
Vol 327 (5962) ◽  
pp. 172-177 ◽  
Author(s):  
Shigehiro A. Kawashima ◽  
Yuya Yamagishi ◽  
Takashi Honda ◽  
Kei-ichiro Ishiguro ◽  
Yoshinori Watanabe

Bub1 is a multi-task protein kinase required for proper chromosome segregation in eukaryotes. Impairment of Bub1 in humans may lead to chromosomal instability (CIN) or tumorigenesis. Yet, the primary cellular substrate of Bub1 has remained elusive. Here, we show that Bub1 phosphorylates the conserved serine 121 of histone H2A in fission yeast Schizosaccharomyces pombe. The h2a-SA mutant, in which all cellular H2A-S121 is replaced by alanine, phenocopies the bub1 kinase-dead mutant (bub1-KD) in losing the centromeric localization of shugoshin proteins. Artificial tethering of shugoshin to centromeres largely restores the h2a-SA or bub1-KD–related CIN defects, a function that is evolutionally conserved. Thus, Bub1 kinase creates a mark for shugoshin localization and the correct partitioning of chromosomes.


2005 ◽  
Vol 25 (24) ◽  
pp. 10721-10730 ◽  
Author(s):  
Toru M. Nakamura ◽  
Bettina A. Moser ◽  
Li-Lin Du ◽  
Paul Russell

ABSTRACT The cellular responses to double-stranded breaks (DSBs) typically involve the extensive accumulation of checkpoint proteins in chromatin surrounding the damaged DNA. One well-characterized example involves the checkpoint protein Crb2 in the fission yeast Schizosaccharomyces pombe. The accumulation of Crb2 at DSBs requires the C-terminal phosphorylation of histone H2A (known as γ-H2A) by ATM family kinases in chromatin surrounding the break. It also requires the constitutive methylation of histone H4 on lysine-20 (K20). Interestingly, neither type of histone modification is essential for the Crb2-dependent checkpoint response. However, H4-K20 methylation is essential in a crb2-T215A strain that lacks a cyclin-dependent kinase phosphorylation site in Crb2. Here we explain this genetic interaction by describing a previously overlooked effect of the crb2-T215A mutation. We show that crb2-T215A cells are able to initiate but not sustain a checkpoint response. We also report that γ-H2A is essential for the DNA damage checkpoint in crb2-T215A cells. Importantly, we show that inactivation of Cdc2 in γ-H2A-defective cells impairs Crb2-dependent signaling to the checkpoint kinase Chk1. These findings demonstrate that full Crb2 activity requires phosphorylation of threonine-215 by Cdc2. This regulation of Crb2 is independent of the histone modifications that are required for the hyperaccumulation of Crb2 at DSBs.


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