A nanobody toolbox to investigate localisation and dynamics of Drosophila titins and other key sarcomeric proteins
- Aix Marseille University, CNRS, IDBM, France
- Max Planck Institute for Multidisciplinary Sciences, Germany
Abstract
Measuring the positions and dynamics of proteins in intact tissues or whole animals is key to understanding protein function. However, to date, this is challenging, as the accessibility of large antibodies to dense tissues is often limited, and fluorescent proteins inserted close to a domain of interest may affect protein function. These complications apply in particular to muscle sarcomeres, arguably one of the most protein-dense assemblies in nature, which complicates studying sarcomere morphogenesis at molecular resolution. Here, we introduce a toolbox of nanobodies recognising various domains of the two Drosophila titin homologs, Sallimus and Projectin, as well as the key sarcomeric proteins Obscurin, a-Actinin and Zasp52. We verified the superior labelling qualities of our nanobodies in muscle tissue as compared to antibodies. By applying our toolbox to larval muscles, we found a gigantic Sallimus isoform stretching more than 2 µm to bridge the sarcomeric I-band, while Projectin covers almost the entire myosin filaments in a polar orientation. Transgenic expression of tagged nanobodies confirmed their high affinity-binding without affecting target protein function. Finally, adding a degradation signal to anti-Sallimus nanobodies suggested that it is difficult to fully degrade Sallimus in mature sarcomeres, however expression of these nanobodies caused developmental lethality. These results may inspire the generation of similar toolboxes for other large protein complexes in Drosophila or mammals.
Data availability
All quantitative source data are provided. Newly generated code is publicly available here: https://github.com/PierreMangeol/titin_PAINTE.coli nanobody expression vectors are available from Addgene (https://www.addgene.org/depositing/82080/).
Article and author information
Author details
Funding
Centre National de la Recherche Scientifique
- Frank Schnorrer
Agence Nationale de la Recherche (ANR-ACHN MUSCLE-FORCES)
- Frank Schnorrer
Human Frontier Science Program (RGP0052/2018)
- Frank Schnorrer
Bettencourt Schueller Foundation
- Frank Schnorrer
Agence Nationale de la Recherche (ANR-10-INBS-04-01)
- Frank Schnorrer
Agence Nationale de la Recherche (ANR-16-CONV-0001)
- Frank Schnorrer
Aix-Marseille Université (Center for Living Systems)
- Frank Schnorrer
Aix-Marseille Université (LabEx-INFORM)
- Vincent Loreau
Centre National de la Recherche Scientifique
- Nuno Miguel Luis
Centre National de la Recherche Scientifique
- Christophe Pitaval
Max-Planck-Gesellschaft
- Dirk Görlich
Aix-Marseille Université
- Pierre Mangeol
European Research Council (ERC-2019-SyG 856118)
- Dirk Görlich
European Research Council (ERC-2019-SyG 856118)
- Frank Schnorrer
Aix-Marseille Université (A*MIDEX)
- Frank Schnorrer
Agence Nationale de la Recherche (ANR-11-IDEX-0001-02)
- Frank Schnorrer
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2023, Loreau et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 2,261
- views
-
- 328
- downloads
-
- 20
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
A nanobody toolbox to investigate localisation and dynamics of Drosophila titins and other key sarcomeric proteins
eLife 12:e79343.
https://doi.org/10.7554/eLife.79343
Further reading
-
- Developmental Biology
Hair follicle development is initiated by reciprocal molecular interactions between the placode-forming epithelium and the underlying mesenchyme. Cell fate transformation in dermal fibroblasts generates a cell niche for placode induction by activation of signaling pathways WNT, EDA, and FGF in the epithelium. These successive paracrine epithelial signals initiate dermal condensation in the underlying mesenchyme. Although epithelial signaling from the placode to mesenchyme is better described, little is known about primary mesenchymal signals resulting in placode induction. Using genetic approach in mice, we show that Meis2 expression in cells derived from the neural crest is critical for whisker formation and also for branching of trigeminal nerves. While whisker formation is independent of the trigeminal sensory innervation, MEIS2 in mesenchymal dermal cells orchestrates the initial steps of epithelial placode formation and subsequent dermal condensation. MEIS2 regulates the expression of transcription factor Foxd1, which is typical of pre-dermal condensation. However, deletion of Foxd1 does not affect whisker development. Overall, our data suggest an early role of mesenchymal MEIS2 during whisker formation and provide evidence that whiskers can normally develop in the absence of sensory innervation or Foxd1 expression.
-
- Developmental Biology
Wing dimorphism is a common phenomenon that plays key roles in the environmental adaptation of aphid; however, the signal transduction in response to environmental cues and the regulation mechanism related to this event remain unknown. Adenosine (A) to inosine (I) RNA editing is a post-transcriptional modification that extends transcriptome variety without altering the genome, playing essential roles in numerous biological and physiological processes. Here, we present a chromosome-level genome assembly of the rose-grain aphid Metopolophium dirhodum by using PacBio long HiFi reads and Hi-C technology. The final genome assembly for M. dirhodum is 447.8 Mb, with 98.50% of the assembled sequences anchored to nine chromosomes. The contig and scaffold N50 values are 7.82 and 37.54 Mb, respectively. A total of 18,003 protein-coding genes were predicted, of which 92.05% were functionally annotated. In addition, 11,678 A-to-I RNA-editing sites were systematically identified based on this assembled M. dirhodum genome, and two synonymous A-to-I RNA-editing sites on CYP18A1 were closely associated with transgenerational wing dimorphism induced by crowding. One of these A-to-I RNA-editing sites may prevent the binding of miR-3036-5p to CYP18A1, thus elevating CYP18A1 expression, decreasing 20E titer, and finally regulating the wing dimorphism of offspring. Meanwhile, crowding can also inhibit miR-3036-5p expression and further increase CYP18A1 abundance, resulting in winged offspring. These findings support that A-to-I RNA editing is a dynamic mechanism in the regulation of transgenerational wing dimorphism in aphids and would advance our understanding of the roles of RNA editing in environmental adaptability and phenotypic plasticity.
