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Nuclear history of a pre-mRNA determines the translational activity of cytoplasmic mRNA
K Matsumoto1, K M Wassarman, A P Wolffe
1Laboratory of Molecular Embryology, National Institute of Child Health and Human Development, NIH, Building 18T, Room 106, Bethesda, MD 20892-5431, USA.
Abstract:
The pathways of synthesis and maturation of pre-messenger RNA in the nucleus have a direct effect on the translational efficiency of mRNA in the cytoplasm. The transcription of intron-less mRNA in vivo directs this mRNA towards translational silencing. The presence of an intron at the 5' end of the transcript relieves this silencing, whereas an intron at the 3' end further represses translation. These regulatory events are strongly dependent on the transcription of pre-mRNA in the nucleus. The impact of nuclear history on regulatory events in the cytoplasm provides a novel mechanism for the control of gene expression.
Insights
Nuclear RNA processing impacts gene expression. Introns in pre-messenger RNA (mRNA) regulate translation, with 5' introns relieving silencing and 3' introns repressing it, revealing nuclear control over cytoplasmic events.
Area of Science:
- Molecular Biology
- Gene Expression Regulation
- RNA Processing
Background:
- Pre-messenger RNA (mRNA) undergoes synthesis and maturation in the nucleus.
- Cytoplasmic mRNA translation efficiency is influenced by nuclear events.
- The role of introns in regulating gene expression is complex and context-dependent.
Purpose of the Study:
- To investigate how the nuclear processing of pre-mRNA affects mRNA translation in the cytoplasm.
- To determine the specific roles of introns in regulating translational efficiency.
- To elucidate a novel mechanism for gene expression control linked to nuclear history.
Main Methods:
- In vivo transcription of intron-less and intron-containing mRNA.
- Analysis of translational efficiency in the cytoplasm.
- Comparison of regulatory effects based on intron location (5' vs. 3').
Main Results:
- Transcription of intron-less mRNA leads to translational silencing.
- The presence of an intron at the 5' end of the transcript alleviates translational silencing.
- An intron located at the 3' end of the transcript further represses translation.
Conclusions:
- Nuclear pre-mRNA transcription and processing significantly impact cytoplasmic translational control.
- Intron position critically dictates the regulatory outcome on translation.
- Nuclear history provides a novel regulatory layer for gene expression control in the cytoplasm.