SMA1, a homolog of the splicing factor Prp28, has a multifaceted role in miRNA biogenesis in Arabidopsis

Nucleic Acids Res. 2018 Sep 28;46(17):9148-9159. doi: 10.1093/nar/gky591.

Abstract

MicroRNAs (miRNAs) are a class of small non-coding RNAs that repress gene expression. In plants, the RNase III enzyme Dicer-like (DCL1) processes primary miRNAs (pri-miRNAs) into miRNAs. Here, we show that SMALL1 (SMA1), a homolog of the DEAD-box pre-mRNA splicing factor Prp28, plays essential roles in miRNA biogenesis in Arabidopsis. A hypomorphic sma1-1 mutation causes growth defects and reduces miRNA accumulation correlated with increased target transcript levels. SMA1 interacts with the DCL1 complex and positively influences pri-miRNA processing. Moreover, SMA1 binds the promoter region of genes encoding pri-miRNAs (MIRs) and is required for MIR transcription. Furthermore, SMA1 also enhances the abundance of the DCL1 protein levels through promoting the splicing of the DCL1 pre-mRNAs. Collectively, our data provide new insights into the function of SMA1/Prp28 in regulating miRNA abundance in plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / physiology*
  • Cloning, Molecular
  • DEAD-box RNA Helicases / genetics
  • DEAD-box RNA Helicases / isolation & purification
  • DEAD-box RNA Helicases / physiology*
  • Gene Expression Regulation, Plant
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Plants, Genetically Modified
  • Saccharomyces cerevisiae Proteins / genetics
  • Sequence Homology, Amino Acid

Substances

  • Arabidopsis Proteins
  • MicroRNAs
  • Saccharomyces cerevisiae Proteins
  • PRP28 protein, S cerevisiae
  • DEAD-box RNA Helicases