Biology subjects

Engel, F.

Publications and source records attributed to Engel, F..

4 recordsLinked to original sources

bioRxiv2024

Elucidation and functional characterization of natural sweetener biosynthesis in hortensia species

Among the various coumarins found in Hydrangea species, the bioactive dihydroisocoumarin known as phyllodulcin (PD) stands out as a non-caloric, high-intensity sweetener, which is up to 800 times sweeter than sucrose. Additionally, PD possesses notable medicinal properties, including antifungal, anti-ulcer, and anti-inflammatory effects. PD also plays several plant-specific roles, such as defending against phytopathogens, responding to abiotic and biotic stresses and regulating hormones. However, the biological function and biosynthetic pathway of PD in Hydrangea remain unexplored. This study employs targeted metabolomic and transcriptomic approaches to uncover the regulatory mechanisms and identify potential candidate genes involved in the biosynthesis of PD. 14 out of 182 different Hydrangea accessions, exhibiting varying levels of PD, were selected for detailed analysis. Accessions of H. macrophylla with high PD levels displayed distinct metabolite profiles compared to those with low PD concentrations. Specifically, pathways involving caffeic acid, ferulic acid, and their derivatives, such as scopolin, scopoletin, esculetin, and fraxetin, were predominant in accessions with low PD concentrations. Conversely, the metabolism of phenylalanine, umbelliferone, p-coumaric acid, naringenin, resveratrol, and Thn C was more active in accessions containing PD. Correlation analysis between PD and these metabolites offered valuable insights into their interrelationships. Transcriptome analysis revealed specific genes involved in phenylpropanoid biosynthesis, flavonoid biosynthesis, and stilbene biosynthesis pathways that are crucial for PD biosynthesis. Moreover, the identification of cyclase and ketoreductase genes, which were up regulated in accessions with high PD, provided further understanding of the biosynthetic pathway leading to PD. Finally, based on metabolite levels and gene expression data, a hypothetical pathway from resveratrol to Thn C was proposed, suggesting its potential involvement in PD biosynthesis. HighlightThe metabolic and transcriptomic analysis led to the identification of specific metabolites and genes that are involved in the biosynthesis of dihydrisocoumarin.

plant biology↗

bioRxiv2022

Adgrg6/Gpr126 is required for myocardial Notch activity and N-cadherin localization to attain trabecular identity

How adhesion G protein-coupled receptors (aGPCRs) control development remains unclear. The aGPCR Adgrg6/Gpr126 has been associated with heart trabeculation. Defects in this process cause cardiomyopathies and embryonic lethality. Yet, how cardiomyocytes attain trabecular identity is poorly understood. Here, we show that Gpr126 regulates Notch activity and N-cadherin localization that are necessary for attaining trabecular identity in zebrafish. Maternal zygotic gpr126stl47 early truncation mutants exhibit hypotrabeculation whereby N-cadherin distributes randomly at apical/basal membranes of compact layer cardiomyocytes. In contrast, gpr126st49 mutants expressing a N-terminal fragment lacking the GPS motif (NTF{Delta}GPS) exhibit a multilayered ventricular wall consisting of polarized cardiomyocytes with normal N-cadherin expression and increased Notch signaling. Notably, endocardially expressed C-terminal fragment (CTF) reinstates trabeculation in gpr126st49 mutants. Collectively, our data indicate domain-specific roles of Gpr126 during trabeculation whereby the NTF maintains cell-cell adhesion and is required for compact wall integrity, while the CTF is essential to provide trabecular identity

developmental biology↗

bioRxiv2021

XePhIR: The zebrafish Xenograft Phenotype Interactive Repository

Zebrafish xenografts are an established model in cancer biology, with a steadily rising number of models and users. However, as of yet, there is no platform dedicated to standardizing protocols and sharing data regarding zebrafish xenograft phenotypes. Here, we present the Xenograft Phenotype Interactive Repository (XePhIR, www.xephir.org) as an independent data sharing platform to deposit, share and repurpose zebrafish xenograft data. Deposition of data and publication with XePhIR will be done after the acceptation of the original publication. This will enhance the reach of the original research article, enhance visibility, and does not interfere with publication or copyrights of the original article. With XePhIR, we strive to fulfill these objectives and reason that this resource will enhance reproducibility and showcase the appeal and applicability of the zebrafish xenograft model.

cancer biology↗

bioRxiv2020

Myogenin controls via AKAP6 non-centrosomal microtubule organizing center formation at the nuclear envelope

Non-centrosomal microtubule organizing centers (MTOC) are pivotal for the function of multiple cell types, but the processes initiating their formation are unknown. Here, we find that the transcription factor myogenin is required in myoblasts for the localization of MTOC proteins to the nuclear envelope. Moreover, myogenin is sufficient in fibroblasts for nuclear envelope MTOC (NE-MTOC) formation and centrosome attenuation. Bioinformatics combined with loss- and gain-of-function experiments identified induction of AKAP6 expression as one central mechanism for myogenin-mediated NE-MTOC formation. Promoter studies indicate that myogenin preferentially induces the transcription of muscle- and NE-MTOC-specific isoforms of Akap6 and Syne1, which encodes nesprin-1, the NE-MTOC anchor protein in muscle cells. Overexpression of AKAP6{beta} and nesprin-1 was sufficient to recruit endogenous MTOC proteins to the nuclear envelope of myoblasts in the absence of myogenin. Taken together, our results illuminate how mammals transcriptionally control the switch from a centrosomal MTOC to an NE-MTOC and identify AKAP6 as a novel NE-MTOC component in muscle cells.

cell biology↗