Flooding stress-induced glycine-rich RNA-binding protein from Nicotiana tabacum.
A cDNA clone for a transcript preferentially expressed during an early phase of flooding was isolated from Nicotiana tabacum. Nucleotide sequencing of the cDNA clone identified an open reading frame that has high homology to the previously reported glycine-rich RNA-binding proteins. The open reading frame consists of 157 amino acids with an N-terminal RNA-recognition motif and a C-terminal glycine-rich domain, and thus the cDNA clone was designated as Nicotiana tabaccum glycine-rich RNA-binding protein-1 (NtGRP1). Expression of NtGRP1 was upregulated under flooding stress and also increased, but at much lower levels, under conditions of cold, drought, heat, high salt content, and abscisic acid treatment. RNA homopolymer-binding assay showed that NtGRP1 binds to all the RNA homopolymers tested with a higher affinity to poly r(G) and poly r(A) than to poly r(U) and poly r(C). Nucleic acid-binding assays showed that NtGRP1 binds to ssDNA, dsDNA, and mRNA. NtGRP1 suppressed expression of the fire luciferase gene in vitro, and the suppression of luciferase gene expression could be rescued by addition of oligonucleotides. Collectively, the data suggest NtGRP1 as a negative modulator of gene expression by binding to DNA or RNA in bulk that could be advantageous for plants in a stress condition like flooding.
Lee
Mi-Ok
MO
School of Biological Sciences and Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 151-742, Korea.
Kim
Keun Pill
KP
Kim
Byung-Gee
BG
Hahn
Ji-Sook
JS
Hong
Choo Bong
CB
D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D002999:Clone Cells; D018076:DNA, Complementary / Q000302:isolation & purification; D018744:DNA, Plant / Q000378:metabolism; D055868:Floods; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017930:Genes, Reporter; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological / Q000187:drug effects; D014026:Nicotiana / Q000187:drug effects / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects
D018076:DNA, Complementary; D018744:DNA, Plant; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D016601:RNA-Binding Proteins; C071360:GRP protein, Nicotiana sylvestris; D000040:Abscisic Acid