Chz1, a nuclear chaperone for histone H2AZ.
The histone variant H2AZ marks nucleosomes flanking the promoters of most genes of budding yeast. The incorporation of H2AZ into chromatin is dependent on the SWR1 complex, which catalyses the replacement of conventional histone H2A with H2AZ. In cells, the pool of unincorporated histone H2AZ has previously been found in association with Nap1, a chaperone for conventional histone H2A-H2B. Here, we report the discovery of Chz1, a histone chaperone that has preference for H2AZ and can also deliver a source of the histone variant for SWR1-dependent histone replacement. Bacterially expressed Chz1 forms a heterotrimer with H2AZ-H2B, stabilizing the association of the histone dimer. We have identified a conserved motif important for histone variant recognition within the H2AZ-interacting domain of Chz1. The presence of this motif in other metazoan proteins suggests that H2AZ-specific chaperones may be widely conserved.
Luk
Ed
E
Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. luked@mail.nih.gov
Vu
Ngoc-Diep
ND
Patteson
Kem
K
Mizuguchi
Gaku
G
Wu
Wei-Hua
WH
Ranjan
Anand
A
Backus
Jonathon
J
Sen
Subhojit
S
Lewis
Marc
M
Bai
Yawen
Y
Wu
Carl
C
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry; D018797:Cell Cycle Proteins / Q000502:physiology; D017124:Conserved Sequence; D019281:Dimerization; D056488:Histone Chaperones; D006657:Histones / Q000378:metabolism*; D006801:Humans; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000502:physiology; D056490:Nucleosome Assembly Protein 1; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D016415:Sequence Alignment
D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C518297:Chz1 protein, S cerevisiae; C518298:HIRIP3 protein, human; D056488:Histone Chaperones; D006657:Histones; C493530:Htz1 protein, S cerevisiae; D018832:Molecular Chaperones; C533556:NAP1 protein, S cerevisiae; C533557:NAP1L1 protein, human; D009687:Nuclear Proteins; D056490:Nucleosome Assembly Protein 1; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C481261:Swr1 protein, S cerevisiae