PDF《Plants》

Molecular Plant 7, 764C772, May

2014 REVIEW ARTICLE Transcriptional Repression by Histone Deacetylases in Plants Xuncheng?Liua,b,2 , Songguang?Yanga,2 , Minglei?Zhaoa,c,2 , Ming?Luoa , Chun-Wei?Yub , Chia-Yang?Chenb , Ready?Taib , and Keqiang?Wub,1 a Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China b Institute of Plant Biology, National Taiwan University, Taipei c University of Chinese Academy of Sciences, Beijing 100049, China ABSTRACT? Reversible histone acetylation and deacetylation at the N-terminus of histone tails play crucial roles in regula- tion of eukaryotic gene activity.

Acetylation of core histones usually induces an '

open'

chromatin structure and is associated with gene activation, whereas deacetylation of histone is often correlated with '

closed'

chromatin and gene repression. Histone deacetylation is catalyzed by histone deacetylases (HDACs). A?growing number of studies have demonstrated the importance of histone deacetylation/acetylation on genome stability, transcriptional regulation, and development in plants. Furthermore, HDACs were shown to interact with various chromatin remolding factors and transcription factors involved in transcriptional repression in multiple developmental processes. In this review, we summarized recent findings on the transcriptional repression mediated by HDACs in plants. Key words: histone deacetylases;

transcriptional repression;

plant development;

abiotic and biotic stresses. Liu X., Yang S., Zhao M., Luo M., Yu C.W., Chen C.Y., Tai R., and Wu K.?(2014). Transcriptional repression by histone deacety- lases in plants. Mol. Plant. 7, 764C772. Introduction Eukaryotic DNA is organized into chromatin with nucle- osomes as the basic building unit. A? single nucleosome is composed of two H3CH4 histone dimmers bridged together as a stable tetramer that is flanked by two sepa- rate H2ACH2B dimmers and is typically enfolded by 147?bp of DNA (Luger et?al., 1997). Each histone has a structured globular domain and an unstructured amino-terminal tail that extends from the core nucleosome. These histone tails provide sites for a variety of posttranslational modifica- tions, such as acetylation, phosphorylation, methylation, ubiquitination, and ADP-ribosylation (Berger, 2007). All of these modifications are reversible and maintained by the controlled action of different histone modifying enzymes influencing chromatin structure. Histone modifications play an important role in the regulation of several biologi- cal processes involving DNA dynamics like transcription, DNA repair, and replication. The acetylation state of the ε-amino group of con- served lysine residues within all four core histones was regulated by the opposing activities of histone acetyl- transferases and histone deacetylases (HDACs). HDACs can remove acetyl groups from histone tail lysines and non-his- tone substrates including transcription factors and other proteins involved in DNA repair and replication, metabo- lism, cytoskeleton dynamics, apoptosis, and cell signaling (Yang and Seto, 2007). Based on sequence similarity and cofactor dependency, HDACs in all eukaryotes are grouped into three families: RPD3/HDA1 (Reduced Potassium Dependence 3/Histone Deacetylase 1), SIR2 (Silent Information Regulator 2), and HD2 (Histone Deacetylase 2)-related protein families (Pandey et?al., 2002). Members of the SIR2 family (Sirtuins) have a catalytic domain that is characterized by the requirement for Nicotine Adenine Dinucleotide (NAD) as a cofactor (Haigis and Guarente,