Biology subjects

Heidecker, M.

Publications and source records attributed to Heidecker, M..

3 recordsLinked to original sources

bioRxiv2026

The long non-coding RNA ACHLYS modulates biomolecular condensates to regulate alternative splicing in root development

Alternative splicing (AS) enables eukaryotes to dynamically adjust RNA and protein isoforms encoded in one gene. Long non-coding RNAs (lncRNA) have emerged as novel regulators of AS through multiple modes of action, including interactions with splicing factor (SF) proteins. Here, we used Arabidopsis thaliana lateral root development to dissect the specificity of lncRNAs in AS regulation. Data mining and a transient expression screen allowed us to identify novel lncRNAs interacting in vivo with the well-characterized SFs Nuclear speckle RNA binding protein A (NSRa) and glycine-rich RNA-binding protein 7 (GRP7), that are differentially expressed during lateral root organogenesis. We identified 4 lncRNAs affecting more than 250 AS events in plant cells, whereby most AS events are unique for each lncRNA. Notably, 19% of the AS events linked to two NSRa-recognized lncRNAs are identical and positively correlated. One lncRNA was named ACHLYS and is highly conserved in several Brassicaceae whereas another was the recently characterized FLAIL lncRNA. ACHLYS knockdown (KD-ACHLYS) and overexpressing lines (OE-ACHLYS) modulate AS regulation in plants and affect root architecture. In parallel, we performed NSRa-iCLIP to determine in vivo genome-wide NSRa binding sites. Interestingly, NSRa binding sites are locally enriched in ACHLYS-dependent AS introns and ACHLYS itself. A specific ACHLYS-induced AS event requires NSRa function showing that ACHLYS defines AS targets through NSRa interaction on specific transcripts. In vitro assays indicate that direct interaction of NSRa with ACHLYS promotes NSRa phase separation. Furthermore, overexpression of ACHLYS in NSRa-GFP plants results in increased accumulation of NSRa in Nuclear speckles. Our data revealed that ACHLYS can modulate NSRa condensates in vivo and binds to NSRa for modifying AS patterns, suggesting a new mechanism where lncRNAs can fine tune SFs regulation and the transcriptome output in eukaryotic organogenesis.

molecular biology↗

bioRxiv2022

Regulatory and evolutionary annotation identifies KAN1, MYB44 and PIF4 as regulators of Arabidopsis lincRNAs expressed in root

Thousands of long intergenic noncoding RNAs (lincRNAs) have been identified in plant genomes. While some lincRNAs have been characterized as important regulators in different biological processes, little is known about the transcriptional regulation for most plant lincRNAs. Through the integration of eight annotation resources, we defined 6,599 high-confidence lincRNA loci in Arabidopsis thaliana. For lincRNAs belonging to different evolutionary age categories, we identified major differences in sequence and chromatin features, as well as in the level of conservation and purifying selection acting during evolution. Spatiotemporal gene expression profiles combined with transcription factor (TF) chromatin immunoprecipitation data were used to construct a TF- lincRNA regulatory network containing 2,659 lincRNAs and 15,686 interactions. We found that properties characterizing lincRNA expression, conservation and regulation differ between plants and animals. Experimental validation confirmed the role of three TFs, KAN1, MYB44, and PIF4, as key regulators controlling root- specific lincRNA expression, demonstrating the predictive power of our network. Furthermore, we identified 58 lincRNAs, regulated by these TFs, showing strong root cell-type specific expression or chromatin accessibility, which are linked with GWAS genetic associations related to root system development and growth. The multi-level genome-wide characterization covering chromatin state information, promoter conservation, and ChIP-based TF binding, for all detectable lincRNAs across 769 expression samples, permits to rapidly define the biological context and relevance of lincRNAs in Arabidopsis regulatory networks. One-line sentenceA multi-level Arabidopsis gene regulatory network identifies novel regulators controlling root-specific lincRNA expression, offering a promising strategy to identify lincRNAs involved in plant biology.

plant biology↗

bioRxiv2021

Expression levels of long noncoding natural antisense transcripts overlapping the UGT73C6 gene affect rosette size of Arabidopsis thaliana

Natural antisense long noncoding RNAs (lncNATs) are involved in the regulation of gene expression in plants, modulating different relevant developmental processes and responses to various stimuli. We identified and characterized two lncNATs (NAT1UGT73C6 and NAT2UGT73C6, collectively NATsUGT73C6) in Arabidopsis thaliana that are transcribed from a gene overlapping UGT73C6, a member of the UGT73C subfamily of genes encoding UDP-glycosyltransferases (UGTs). Expression of both NATsUGT73C6 is developmentally controlled and occurs independently of the transcription of UGT73C6 in cis. Downregulation of NATsUGT73C6 levels through artificial microRNAs results in a reduction of the rosette area, while constitutive overexpression of NAT1UGT73C6 or NAT2UGT73C6 leads to the opposite phenotype, an increase in rosette size. This activity of NATsUGT73C6 relies on its RNA sequence, and, although modulation of UGT73C6 in cis cannot be excluded, the observed phenotypes are not a consequence of the regulation of UGT73C6 in trans. The NATsUGT73C6 levels were shown to affect cell proliferation and thus individual leaf size. Consistent with this concept, our data suggest that the NATsUGT73C6 modulate the expression levels of key transcription factors involved in regulating leaf growth by modulating cell proliferation. These findings thus reveal an additional regulatory layer on the process of leaf growth.

plant biology↗