A quantitative hypermorphic CNGC allele confers ectopic calcium flux and impairs cellular development
- Ludwig Maximilian University of Munich, Germany
- Friedrich-Alexander Universität Erlangen-Nürnberg, Germany
Abstract
The coordinated control of Ca2+ signaling is essential for development in eukaryotes. Cyclic nucleotide-gated channel (CNGC) family members mediate Ca2+ influx from cellular stores in plants1-4. Here we report the unusual genetic behavior of a quantitative gain-of-function CNGC mutation (brush) in Lotus japonicus resulting in a leaky tetrameric channel. brush resides in a cluster of redundant CNGCs encoding subunits which resemble metazoan voltage-gated potassium (Kv1-Kv4) channels in assembly and gating properties. Plants homozygous for brush are impaired in root development and infection by nitrogen-fixing rhizobia which segregated as a recessive monogenic trait. The brush allele exhibited quantitative behavior since overexpression of the cluster subunits was required to suppress the brush phenotype. The results reveal a mechanism by which quantitative competition between channel subunits for tetramer assembly can impact the phenotype of the mutation carrier.
Article and author information
Author details
Funding
Deutsche Forschungsgemeinschaft (FOR964 (Calcium))
- Kristina Haage
- Petra Dietrich
- Martin Parniske
H2020 European Research Council (340904 (EvolvingNodules))
- Martin Parniske
Alexander von Humboldt-Stiftung
- David M Chiasson
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Chiasson 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
-
- 3,019
- views
-
- 643
- downloads
-
- 29
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Further reading
-
- Chromosomes and Gene Expression
RNA interference (RNAi) is a conserved pathway that utilizes Argonaute proteins and their associated small RNAs to exert gene regulatory function on complementary transcripts. While the majority of germline-expressed RNAi proteins reside in perinuclear germ granules, it is unknown whether and how RNAi pathways are spatially organized in other cell types. Here, we find that the small RNA biogenesis machinery is spatially and temporally organized during Caenorhabditis elegans embryogenesis. Specifically, the RNAi factor, SIMR-1, forms visible concentrates during mid-embryogenesis that contain an RNA-dependent RNA polymerase, a poly-UG polymerase, and the unloaded nuclear Argonaute protein, NRDE-3. Curiously, coincident with the appearance of the SIMR granules, the small RNAs bound to NRDE-3 switch from predominantly CSR-class 22G-RNAs to ERGO-dependent 22G-RNAs. NRDE-3 binds ERGO-dependent 22G-RNAs in the somatic cells of larvae and adults to silence ERGO-target genes; here we further demonstrate that NRDE-3-bound, CSR-class 22G-RNAs repress transcription in oocytes. Thus, our study defines two separable roles for NRDE-3, targeting germline-expressed genes during oogenesis to promote global transcriptional repression, and switching during embryogenesis to repress recently duplicated genes and retrotransposons in somatic cells, highlighting the plasticity of Argonaute proteins and the need for more precise temporal characterization of Argonaute-small RNA interactions.
-
- Chromosomes and Gene Expression
- Genetics and Genomics
A new method for mapping torsion provides insights into the ways that the genome responds to the torsion generated by RNA polymerase II.
