Format

Send to

Choose Destination
Cell Host Microbe. 2014 Feb 12;15(2):139-52. doi: 10.1016/j.chom.2014.01.011.

CYCLOPS, a DNA-binding transcriptional activator, orchestrates symbiotic root nodule development.

Author information

1
Faculty of Biology, Genetics, University of Munich (LMU), D-82152 Martinsried, Germany.
2
Faculty of Biology, Genetics, University of Munich (LMU), D-82152 Martinsried, Germany. Electronic address: parniske@lmu.de.

Abstract

Nuclear calcium oscillations are a hallmark of symbiotically stimulated plant root cells. Activation of the central nuclear decoder, calcium- and calmodulin-dependent kinase (CCaMK), triggers the entire symbiotic program including root nodule organogenesis, but the mechanism of signal transduction by CCaMK was unknown. We show that CYCLOPS, a direct phosphorylation substrate of CCaMK, is a DNA-binding transcriptional activator. Two phosphorylated serine residues within the N-terminal negative regulatory domain of CYCLOPS are necessary for its activity. CYCLOPS binds DNA in a sequence-specific and phosphorylation-dependent manner and transactivates the NODULE INCEPTION (NIN) gene. A phosphomimetic version of CYCLOPS was sufficient to trigger root nodule organogenesis in the absence of rhizobia and CCaMK. CYCLOPS thus induces a transcriptional activation cascade, in which NIN and a heterotrimeric NF-Y complex act in hierarchical succession to initiate symbiotic root nodule development.

PMID:
24528861
DOI:
10.1016/j.chom.2014.01.011
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center