XB-ART-54039Elife. September 25, 2017; 6
A quantitative hypermorphic CNGC allele confers ectopic calcium flux and impairs cellular development.
The coordinated control of Ca(2+) signaling is essential for development in eukaryotes. Cyclic nucleotide-gated channel (CNGC) family members mediate Ca(2+) influx from cellular stores in plants(1-4). 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.
PubMed ID: 28933692
Article link: Elife.