Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that function as guide molecules in RNA silencing.
Plant miRNAs are critical for plant growth, development and stress response, and are processed in Arabidopsis from primary miRNA transcripts (pri-miRNAs) by the endonuclease activity of the DICER-LIKE1 (DCL1) protein complex. Mature miRNAs are loaded onto and guide an ARGONAUTE1 (AGO1) effector complex, leading to target mRNA silencing.
The miRNA pathway is under tight temporal and spatial control and is regulated at multiple levels from transcription and precursor processing through miRNA mode of action and turnover.
During my PhD period we have shown that the STA1 protein, a factor for pre-mRNA splicing and mRNA stability, is specifically involved in the splicing of pri-miRNAs and in the modulation of DCL1 transcript levels.
Also, we established a novel and essential regulatory network in which HYL1, an essential factor for pri-miRNA processing, is rapidly degraded by an unknown protease and the proteolytic regulation is dynamically modulated by COP1 in response to light-to-dark transition, implying the integration of light signaling into miRNA biogenesis.
Finally, although important questions need to be addressed to establish a valid link, we provide encouraging evidence of the involvement of chromatin remodeling factors FAS1 and FAS2 in miRNA biogenesis. Together, we have expanded our understanding of the intersections between miRNA biogenesis and other pathways.
Plant miRNAs are critical for plant growth, development and stress response, and are processed in Arabidopsis from primary miRNA transcripts (pri-miRNAs) by the endonuclease activity of the DICER-LIKE1 (DCL1) protein complex. Mature miRNAs are loaded onto and guide an ARGONAUTE1 (AGO1) effector complex, leading to target mRNA silencing.
The miRNA pathway is under tight temporal and spatial control and is regulated at multiple levels from transcription and precursor processing through miRNA mode of action and turnover.
During my PhD period we have shown that the STA1 protein, a factor for pre-mRNA splicing and mRNA stability, is specifically involved in the splicing of pri-miRNAs and in the modulation of DCL1 transcript levels.
Also, we established a novel and essential regulatory network in which HYL1, an essential factor for pri-miRNA processing, is rapidly degraded by an unknown protease and the proteolytic regulation is dynamically modulated by COP1 in response to light-to-dark transition, implying the integration of light signaling into miRNA biogenesis.
Finally, although important questions need to be addressed to establish a valid link, we provide encouraging evidence of the involvement of chromatin remodeling factors FAS1 and FAS2 in miRNA biogenesis. Together, we have expanded our understanding of the intersections between miRNA biogenesis and other pathways.
| Original language | English |
|---|
| Publisher | Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen |
|---|---|
| Number of pages | 79 |
| Publication status | Published - 2015 |