The protein kinase TOUSLED is required for maintenance of transcriptional gene silencing in Arabidopsis.
TOUSLED-like kinases (TLKs) are highly conserved in plants and animals, but direct evidence linking TLKs and transcriptional gene silencing is lacking. We isolated two new alleles of TOUSLED (TSL). Mutations of TSL in ros1 reactivate the transcriptionally silent 35S-NPTII transgene and the transcriptionally silent endogenous loci TSI (TRANSCRIPTIONAL SILENCING INFORMATION). Chromatin immunoprecipitation (ChIP) analysis shows that histone H3Lys9 dimethylation is decreased in the reactivated transgene and endogenous TSI loci in the tsl ros1 mutant. However, there is no change in DNA methylation in the affected loci. Western blot and ChIP assay suggest that TSL might not be responsible for histone H3Ser10 phosphorylation. The tsl seedlings were more sensitive to DNA damage reagent methyl methanesulphonate and UV-B light. Our results provide direct evidence for a crucial role of the TOUSLED protein kinase in the maintenance of transcriptional gene silencing in some genomic regions in a DNA-methylation-independent manner in Arabidopsis.
Wang
Yu
Y
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Yuanmingyuan Xilu #2, Haidai Dist, Beijing 100094, China.
Liu
Jun
J
Xia
Ran
R
Wang
Junguo
J
Shen
Jie
J
Cao
Rui
R
Hong
Xuhui
X
Zhu
Jian-Kang
JK
Gong
Zhizhong
Z
D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D047369:Chromatin Immunoprecipitation; D004249:DNA Damage / Q000235:genetics; D019175:DNA Methylation; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D006657:Histones / Q000032:analysis / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D011836:Radiation Tolerance / Q000235:genetics; D012694:Serine / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics; D014466:Ultraviolet Rays
D029681:Arabidopsis Proteins; D006657:Histones; D009687:Nuclear Proteins; C471271:ROS1 protein, Arabidopsis; D012694:Serine; C084661:tousled protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; D008239:Lysine