A new rice zinc-finger protein binds to the O2S box of the alpha-amylase gene promoter.
A putative transcription factor, named RAMY, that binds to the 20-bp O2S sequences of the regulatory region of the Amy2 gene promoter has been identified using the yeast one-hybrid system from a rice library. The full length RAMY cDNA clone encodes a 218-amino acid protein and is homologous to the late embryogenesis-abundant protein (LEA5). In vitro mutagenesis and electrophoretic mobility shift assays confirmed that RAMY can bind with O2S specifically through an unusual zinc finger with a CXCX(4)CX(2)H consensus sequence. Low levels of RAMY mRNAs were detected in rice leaves and roots by Northern blot hybridization. The plant hormone gibberellin (GA) induces expression of both RAMY and Amy2 genes, as performed by Northern blot hybridization, but the increase in RAMY mRNA level occurs prior to that of the Amy2 mRNA level in the GA-treated aleurone tissues. These data suggest that RAMY may act as a trans-acting protein and is probably involved in the GA-induced expression of the rice alpha-amylase gene.
Peng
Rihe
R
Shanghai Key Laboratory of Agricultural Genetic and Breeding, Agro-Biotechnology Research Center, Shanghai Academy of Agricultural Sciences, China. pengrihe69@yahoo.com
Yao
Quanhong
Q
Xiong
Aisheng
A
Fan
Huiqin
H
Li
Xian
X
Peng
Youliang
Y
Cheng
Zong-Ming
ZM
Li
Yi
Y
D000595:Amino Acid Sequence; D001483:Base Sequence; D005875:Gibberellins; D008969:Molecular Sequence Data; D012275:Oryza / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D016335:Zinc Fingers; D000516:alpha-Amylases / Q000235:genetics* / Q000378:metabolism
D005875:Gibberellins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C007842:gibberellic acid; D000516:alpha-Amylases