The RNA binding protein ELF9 directly reduces SUPPRESSOR OF OVEREXPRESSION OF CO1 transcript levels in arabidopsis, possibly via nonsense-mediated mRNA decay.
SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1) is regulated by a complex transcriptional regulatory network that allows for the integration of multiple floral regulatory inputs from photoperiods, gibberellin, and FLOWERING LOCUS C. However, the posttranscriptional regulation of SOC1 has not been explored. Here, we report that EARLY FLOWERING9 (ELF9), an Arabidopsis thaliana RNA binding protein, directly targets the SOC1 transcript and reduces SOC1 mRNA levels, possibly through a nonsense-mediated mRNA decay (NMD) mechanism, which leads to the degradation of abnormal transcripts with premature translation termination codons (PTCs). The fully spliced SOC1 transcript is upregulated in elf9 mutants as well as in mutants of NMD core components. Furthermore, a partially spliced SOC1 transcript containing a PTC is upregulated more significantly than the fully spliced transcript in elf9 in an ecotype-dependent manner. A Myc-tagged ELF9 protein (MycELF9) directly binds to the partially spliced SOC1 transcript. Previously known NMD target transcripts of Arabidopsis are also upregulated in elf9 and recognized directly by MycELF9. SOC1 transcript levels are also increased by the inhibition of translational activity of the ribosome. Thus, the SOC1 transcript is one of the direct targets of ELF9, which appears to be involved in NMD-dependent mRNA quality control in Arabidopsis.
School of Biological Sciences, Seoul National University, Seoul 151-747, Korea.
Hae-Ryong
HR
Song
Ju-Dong
JD
Song
Jung-Nam
JN
Cho
Richard M
RM
Amasino
Bosl
B
Noh
Yoo-Sun
YS
Noh
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D017440:Photoperiod; D012326:RNA Splicing; D020871:RNA Stability; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000032:analysis / Q000737:chemistry / Q000502:physiology*; D016415:Sequence Alignment
C419046:AGL20 protein, Arabidopsis; D029681:Arabidopsis Proteins; C543132:ELF9 protein, Arabidopsis; D026161:MADS Domain Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins