Muscle function and homeostasis require cytokine inhibition of AKT activity in Drosophila
Abstract
Unpaired ligands are secreted signals that act via a GP130-like receptor, domeless, to activate JAK/STAT signaling in Drosophila. Like many mammalian cytokines, unpaireds can be activated by infection and other stresses and can promote insulin resistance in target tissues. However, the importance of this effect in non-inflammatory physiology is unknown. Here, we identify a requirement for unpaired-JAK signaling as a metabolic regulator in healthy adult Drosophila muscle. Adult muscles show basal JAK-STAT signaling activity in the absence of any immune challenge. Plasmatocytes (Drosophila macrophages) are an important source of this tonic signal. Loss of the dome receptor on adult muscles significantly reduces lifespan and causes local and systemic metabolic pathology. These pathologies result from hyperactivation of AKT and consequent deregulation of metabolism. Thus, we identify a cytokine signal that must be received in muscle to control AKT activity and metabolic homeostasis.
Data availability
Data has been made available on Zenodo, under the doi 10.5281/zenodo.3608626.
-
Raw data for Kierdorf et al,Zenodo, doi:10.5281/zenodo.3608626.
Article and author information
Author details
Funding
Wellcome (Investigator Award 207467/Z/17/Z)
- Marc S Dionne
Biotechnology and Biological Sciences Research Council (Research Grant BB/P000592/1)
- Katrin Kierdorf
- Pinar Ustaoglu
- Marc S Dionne
Biotechnology and Biological Sciences Research Council (Research Grant BB/L020122/2)
- Jessica Sharrock
- Marc S Dionne
Medical Research Council (Research Grant MR/L018802/2)
- Katrin Kierdorf
- Marc S Dionne
Deutsche Forschungsgemeinschaft (Research fellowship KI-1876/1)
- Katrin Kierdorf
Biotechnology and Biological Sciences Research Council (PhD studentship BB/L502169/1)
- Jessica Sharrock
Deutsche Forschungsgemeinschaft (CIBSS-EXC-2189-Project ID 390939984)
- Fabian Hersperger
European Commission (ERC starting grant 337689)
- Olaf Gross
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- K VijayRaghavan, National Centre for Biological Sciences, Tata Institute of Fundamental Research, India
Version history
- Received: September 4, 2019
- Accepted: January 10, 2020
- Accepted Manuscript published: January 16, 2020 (version 1)
- Accepted Manuscript updated: January 20, 2020 (version 2)
- Version of Record published: February 3, 2020 (version 3)
Copyright
© 2020, Kierdorf 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
-
- 2,782
- views
-
- 388
- downloads
-
- 18
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
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)
Further reading
-
- Developmental Biology
- Structural Biology and Molecular Biophysics
The receptor tyrosine kinase ROR2 mediates noncanonical WNT5A signaling to orchestrate tissue morphogenetic processes, and dysfunction of the pathway causes Robinow syndrome, brachydactyly B, and metastatic diseases. The domain(s) and mechanisms required for ROR2 function, however, remain unclear. We solved the crystal structure of the extracellular cysteine-rich (CRD) and Kringle (Kr) domains of ROR2 and found that, unlike other CRDs, the ROR2 CRD lacks the signature hydrophobic pocket that binds lipids/lipid-modified proteins, such as WNTs, suggesting a novel mechanism of ligand reception. Functionally, we showed that the ROR2 CRD, but not other domains, is required and minimally sufficient to promote WNT5A signaling, and Robinow mutations in the CRD and the adjacent Kr impair ROR2 secretion and function. Moreover, using function-activating and -perturbing antibodies against the Frizzled (FZ) family of WNT receptors, we demonstrate the involvement of FZ in WNT5A-ROR signaling. Thus, ROR2 acts via its CRD to potentiate the function of a receptor super-complex that includes FZ to transduce WNT5A signals.
-
- Cell Biology
- Developmental Biology
The generation of distinct cell fates during development depends on asymmetric cell division of progenitor cells. In the central and peripheral nervous system of Drosophila, progenitor cells respectively called neuroblasts or sensory organ precursors use PAR polarity during mitosis to control cell fate determination in their daughter cells. How polarity and the cell cycle are coupled, and how the cell cycle machinery regulates PAR protein function and cell fate determination is poorly understood. Here, we generate an analog sensitive allele of CDK1 and reveal that its partial inhibition weakens but does not abolish apical polarity in embryonic and larval neuroblasts and leads to defects in polarisation of fate determinants. We describe a novel in vivo phosphorylation of Bazooka, the Drosophila homolog of PAR-3, on Serine180, a consensus CDK phosphorylation site. In some tissular contexts, phosphorylation of Serine180 occurs in asymmetrically dividing cells but not in their symmetrically dividing neighbours. In neuroblasts, Serine180 phosphomutants disrupt the timing of basal polarisation. Serine180 phosphomutants also affect the specification and binary cell fate determination of sensory organ precursors as well as Baz localisation during their asymmetric cell divisions. Finally, we show that CDK1 phosphorylates Serine-S180 and an equivalent Serine on human PAR-3 in vitro.