Related Experiment Video
Updated: Jun 22, 2025
14:43
Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis
Published on: July 23, 2014
13.4K
Widespread changes to the translational landscape in a maize microRNA biogenesis mutant
1Biology Department, East Carolina University, Greenville, North Carolina, USA.
The Plant Journal : for Cell and Molecular Biology
|July 4, 2024
Summary
MicroRNAs regulate gene expression in plants. This study reveals that DICER-LIKE1 (DCL1) primarily uses translational repression for miRNA targets and impacts ribosome biogenesis.
Area of Science:
- Plant molecular biology
- Gene regulation
- Biochemistry
Background:
- MicroRNAs (miRNAs) are crucial regulators of gene expression in plants and animals.
- DICER-LIKE1 (DCL1) is essential for plant miRNA biogenesis, processing pri-miRNAs and pre-miRNAs.
- The precise mechanisms of miRNA-mediated gene repression (translational repression vs. mRNA degradation) remain unclear in crops like maize.
Purpose of the Study:
- To investigate the genome-wide contribution of translational repression versus mRNA degradation by miRNAs in maize.
- To elucidate the role of DICER-LIKE1 (DCL1) in miRNA-mediated gene regulation.
- To explore potential non-miRNA-related functions of DCL1.
Main Methods:
- Combined ribosome profiling and RNA-sequencing (RNA-seq) in maize.
- Analysis of the maize fuzzy tassel (fzt) mutant, which has a hypomorphic mutation in DCL1.
- Comparative analysis of miRNA and mRNA levels and ribosome occupancy.
Main Results:
- Translational repression is a significant mechanism for regulating most miRNA targets in maize.
- Approximately one-third of miRNA targets are primarily regulated at the translational level.
- The DCL1 mutant (fzt) exhibits altered ribosome profiles, suggesting a role for DCL1 in ribosome biogenesis.
Conclusions:
- DICER-LIKE1 (DCL1) plays a critical role in shaping the translational landscape in plants.
- DCL1 influences gene expression through both miRNA-dependent translational repression and miRNA-independent mechanisms affecting ribosome biogenesis.
- Understanding these mechanisms is vital for crop improvement and stress response.
Related Concept Videos
01:22MicroRNAs
3.0K
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
3.0K
02:57piRNA - Piwi-interacting RNAs
6.8K
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
6.8K
02:24Regulation of Expression Occurs at Multiple Steps
22.6K
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
22.6K
02:28Leaky Scanning
5.1K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.1K
02:51mRNA Stability and Gene Expression
5.6K
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Cis-acting Elements involved in mRNA stability
5.6K
01:23Regulation of Expression at Multiple Steps
888
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the...
888