Histone acetyltransferases in rice (Oryza sativa L.): phylogenetic analysis, subcellular localization and expression.
BACKGROUND
Histone acetyltransferases (HATs) play an important role in eukaryotic transcription. Eight HATs identified in rice (OsHATs) can be organized into four families, namely the CBP (OsHAC701, OsHAC703, and OsHAC704), TAFII250 (OsHAF701), GNAT (OsHAG702, OsHAG703, and OsHAG704), and MYST (OsHAM701) families. The biological functions of HATs in rice remain unknown, so a comprehensive protein sequence analysis of the HAT families was conducted to investigate their potential functions. In addition, the subcellular localization and expression patterns of the eight OsHATs were analyzed.


RESULTS
On the basis of a phylogenetic and domain analysis, monocotyledonous CBP family proteins can be subdivided into two groups, namely Group I and Group II. Similarly, dicotyledonous CBP family proteins can be divided into two groups, namely Group A and Group B. High similarities of protein sequences, conserved domains and three-dimensional models were identified among OsHATs and their homologs in Arabidopsis thaliana and maize. Subcellular localization predictions indicated that all OsHATs might localize in both the nucleus and cytosol. Transient expression in Arabidopsis protoplasts confirmed the nuclear and cytosolic localization of OsHAC701, OsHAG702, and OsHAG704. Real-time quantitative polymerase chain reaction analysis demonstrated that the eight OsHATs were expressed in all tissues examined with significant differences in transcript abundance, and their expression was modulated by abscisic acid and salicylic acid as well as abiotic factors such as salt, cold, and heat stresses.


CONCLUSIONS
Both monocotyledonous and dicotyledonous CBP family proteins can be divided into two distinct groups, which suggest the possibility of functional diversification. The high similarities of protein sequences, conserved domains and three-dimensional models among OsHATs and their homologs in Arabidopsis and maize suggested that OsHATs have multiple functions. OsHAC701, OsHAG702, and OsHAG704 were localized in both the nucleus and cytosol in transient expression analyses with Arabidopsis protoplasts. OsHATs were expressed constitutively in rice, and their expression was regulated by exogenous hormones and abiotic stresses, which suggested that OsHATs may play important roles in plant defense responses.
South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Xia
X
Liu
Ming
M
Luo
Wei
W
Zhang
Jinhui
J
Zhao
Jianxia
J
Zhang
Keqiang
K
Wu
Lining
L
Tian
Jun
J
Duan
D000040:Abscisic Acid / Q000494:pharmacology; D000107:Acetylation / Q000187:drug effects; D000595:Amino Acid Sequence; D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology; D003080:Cold Temperature; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D051548:Histone Acetyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006358:Hot Temperature; D008969:Molecular Sequence Data; D005810:Multigene Family; D012275:Oryza / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011523:Protoplasts / Q000187:drug effects / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020156:Salicylic Acid / Q000494:pharmacology; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology
D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid; D051548:Histone Acetyltransferases; D020156:Salicylic Acid