Search bioRxiv⌕ Search

Biology subjects

Matsubayashi, Y.

Publications and source records attributed to Matsubayashi, Y..

4 recordsLinked to original sources

Antagonistic interactions between CLAVATA receptors shape maize ear development

Meristem activity is controlled by the CLAVATA (CLV) signaling pathway, which involves a suite of leucine rich receptor (LRR) receptors, receptor-like proteins and CLV- EMBRYO SURROUNDING REGION (CLE) peptide ligands. FASCIATED EAR 3 (FEA3) is a leucine rich receptor (LRR) receptor-like protein important for meristem maintenance in maize, and acts independently of canonical CLV receptors. Weak alleles of fea3 can increase yield-related traits in maize, so understanding how FEA3 controls inflorescence development can maximize its potential as a crop improvement target. To identify FEA3s interaction network, we used TurboID-based proximity labeling in maize meristems, and identified a putative co-receptor, BARELY ANY MERISTEM 1D (BAM1D). BAM1D and FEA3 proximity labeling proteomes shared over 100 proteins, including many signaling proteins, suggesting they feed into a common signaling pathway. fea3 was epistatic to bam1d in the control of IM size, supporting the idea that FEA3 and BAM1D interact physically. However, fea3 and bam1d act antagonistically, because fea3 mutants had larger inflorescence meristems (IMs), whereas bam1d mutants produced smaller IMs. Together, this study demonstrates how in vivo TurboID-based proximity labeling clarifies complex genetic interactions between CLV receptors and expands our knowledge of downstream signaling components of CLV signaling pathways, which are largely uncharacterized. Our findings support the notion that multiple, partially overlapping CLV receptor complexes coordinately control meristem maintenance.

plant biology↗

Evidence for the major role of PH4EFB in the prolyl 4-hydroxylation of Drosophila collagen IV

Collagens are fundamental components of extracellular matrices, requiring precise intracellular post-translational modifications for proper function. Among the modifications, prolyl 4-hydroxylation is critical to stabilise the collagen triple helix. In humans, this reaction is mediated by collagen prolyl 4-hydroxylases (P4Hs). While humans possess three genes encoding these enzymes (P4Hs), Drosophila melanogaster harbour at least 26 candidates for collagen P4Hs despite its simple genome, and it is poorly understood which of them are actually working on collagen in the fly. In this study, we addressed this question by carrying out thorough bioinformatic and biochemical analyses. We demonstrate that among the 26 potential collagen P4Hs, PH4EFB shares the highest homology with vertebrate collagen P4Hs. Furthermore, while collagen P4Hs and their substrates must exist in the same cells, our transcriptomic analyses at the tissue and single cell levels showed a global co-expression of PH4EFB but not the other P4H-related genes with the collagen IV genes. Moreover, expression of PH4EFB during embryogenesis was found to precede that of collagen IV, presumably enabling efficient collagen modification by PH4EFB. Finally, biochemical assays confirm that PH4EFB binds collagen, supporting its direct role in collagen IV modification. Collectively, we identify PH4EFB as the primary and potentially constitutive prolyl 4-hydroxylase responsible for collagen IV biosynthesis in Drosophila. Our findings highlight the remarkably simple nature of Drosophila collagen IV biosynthesis, which may serve as a blueprint for defining the minimal requirements for collagen engineering.

biochemistry↗

Explainable AI-guided identification of a novel protein-RNA interactive frame for selective siRNA accumulation in plants

Small interference RNA (siRNA) selectively accumulates and acts in RNA interference (RNAi). Although the components involved in siRNA production have long been the focus of studies to elucidate RNAi processes, the mechanism(s) for selectivity of siRNA (or RNAi effectivity) remains unclear. In a novel approach, we developed a progressive deep learning (DL) framework integrating Transformer and convolutional neural networks to predict the sequences of selectively accumulated siRNAs across various land plant species. These approaches achieved high-accuracy prediction of selectively accumulated 21-nt siRNAs and further identified their key signals, which are positionally and linguistically flexible sequences surrounding the target siRNA. We experimentally validated the contribution of these flexible key signal sequences to siRNA accumulation selectivity using virus-induced gene silencing (VIGS) in Nicotiana benthamiana, and identified RNA-binding proteins that directly recognize the key signal sequences to act for selective siRNA accumulation. These insights provide a novel framework for investigating RNAi mechanisms in plants. One sentence summaryWe discovered a novel mechanism centered on RNA-protein interactions involving the selective accumulation of small-RNAs in plants by applying advanced deep learning frames.

plant biology↗

Integration of shoot-derived polypeptide signals by root TGA transcription factors is essential for survival under fluctuating nitrogen environments

Unlike plants in the field, which experience significant temporal fluctuations in environmental conditions, plants in the laboratory are typically grown in controlled, stable environments. Therefore, signaling pathways evolved for survival in continuously fluctuating environments often remain functionally latent in laboratory settings. Here, we show that TGA1 and TGA4 act as hub transcription factors through which the expression of genes involved in high-affinity nitrate uptake are regulated in response to shoot-derived phloem mobile polypeptides, CEP DOWNSTREAM 1 (CEPD1), CEPD2 and CEPD-like 2 (CEPDL2) as nitrogen (N) deficiency signals, and Glutaredoxin S1 (GrxS1) to GrxS8 as N sufficiency signals. CEPD1/2/CEPDL2 and GrxS1-S8 competitively bind to TGA1/4 in roots, with the former acting as transcription coactivators that enhance the uptake of nitrate, while the latter function as corepressor complexes together with TOPLESS to limit nitrate uptake. Arabidopsis plants deficient in TGA1/4 maintain basal nitrate uptake and exhibit growth similar to wild-type plants in a stable N environment, but were impaired in regulation of nitrate acquisition in response to shoot N demand, leading to defective growth under continuously fluctuating N environments where rhizosphere nitrate ions switch periodically between deficient and sufficient states. TGA1/4 are crucial transcription factors that enable plants to survive under fluctuating and challenging N environmental conditions.

plant biology↗