TY - JOUR
T1 - Four amino acids guide the assembly or disassembly of Arabidopsis histone H3.3-containing nucleosomes
AU - Shi, Leilei
AU - Wang, Jing
AU - Hong, Fang
AU - Spector, David L.
AU - Fang, Yuda
PY - 2011/6/28
Y1 - 2011/6/28
N2 - The histone variant H3.3 and the canonical histone H3.1, which differ in only 4- to 5-aa positions, are coexpressed in complex multicellular eukaryotes from fly to human and plant. H3.3 ismainly associated with active chromatin by replacing H3.1 through chaperones such as histone regulator A, death domain associated protein DAXX, thalassemia/mental retardation syndrome X-linked homolog ATRX, or proto-oncogene protein DEK and plays important roles in the germline, epigenetic memory, and reprogramming. However, the signals within H3.3 that serve as a guide for its dynamic deposition or depletion in plant chromatin are not clear. Here, we show that Arabidopsis histone H3.3 differs from H3.1 by 4-aa sites: amino acids 31, 41, 87, and 90. Although histone H3.1 is highly enriched in chromocenters, H3.3 is present in nucleolar foci in addition to being diffusely distributed in the nucleoplasm. We have evaluated the function of the 4 aa that differ between H3.1 and H3.3. We show that amino acid residue 87, and to some extent residue 90, of Arabidopsis histone H3.3 are critical for its deposition into rDNA arrays. When RNA polymerase I-directed nucleolar transcription is inhibited, wild type H3.3, but not H3.3 containing mutations at residues 31 and 41, is depleted from the rDNA arrays. Together, our results are consistent with a model in which amino acids 87 and 90 in the core domain of H3.3 guide nucleosome assembly, whereas amino acids 31 and 41 in the N-terminal tail of Arabidopsis H3.3 guide nucleosome disassembly in nucleolar rDNA.
AB - The histone variant H3.3 and the canonical histone H3.1, which differ in only 4- to 5-aa positions, are coexpressed in complex multicellular eukaryotes from fly to human and plant. H3.3 ismainly associated with active chromatin by replacing H3.1 through chaperones such as histone regulator A, death domain associated protein DAXX, thalassemia/mental retardation syndrome X-linked homolog ATRX, or proto-oncogene protein DEK and plays important roles in the germline, epigenetic memory, and reprogramming. However, the signals within H3.3 that serve as a guide for its dynamic deposition or depletion in plant chromatin are not clear. Here, we show that Arabidopsis histone H3.3 differs from H3.1 by 4-aa sites: amino acids 31, 41, 87, and 90. Although histone H3.1 is highly enriched in chromocenters, H3.3 is present in nucleolar foci in addition to being diffusely distributed in the nucleoplasm. We have evaluated the function of the 4 aa that differ between H3.1 and H3.3. We show that amino acid residue 87, and to some extent residue 90, of Arabidopsis histone H3.3 are critical for its deposition into rDNA arrays. When RNA polymerase I-directed nucleolar transcription is inhibited, wild type H3.3, but not H3.3 containing mutations at residues 31 and 41, is depleted from the rDNA arrays. Together, our results are consistent with a model in which amino acids 87 and 90 in the core domain of H3.3 guide nucleosome assembly, whereas amino acids 31 and 41 in the N-terminal tail of Arabidopsis H3.3 guide nucleosome disassembly in nucleolar rDNA.
KW - Chromatin remodeling
KW - H3 dynamics
KW - Histone code
KW - Nucleolar dominance
UR - http://www.scopus.com/inward/record.url?scp=79960590442&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79960590442&partnerID=8YFLogxK
U2 - 10.1073/pnas.1017882108
DO - 10.1073/pnas.1017882108
M3 - Article
C2 - 21670303
AN - SCOPUS:79960590442
SN - 0027-8424
VL - 108
SP - 10574
EP - 10578
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 26
ER -