Skip to main content
. 2014 Dec 9;15(12):22801–22814. doi: 10.3390/ijms151222801

Figure 4.

Figure 4

Model for the mode of action of 14-3-3κ in the context of light signaling. I. Upon light illumination, phytochromes (Phy) rapidly convert to an active form and translocate into a nuclear speckle where they bind to negative regulators of light signalling, PHYTOCHROME INTERACTING FACTORs (PIFs). An E3 ligase, CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) polyubiquitinates Phy, but not PIFs, to be degraded by the 26S proteasome, serving as a negative feedback mechanism in light signaling; II. Phy-bound PIFs are phosphorylated, E3 ligases, LIGHT-RESPONSE BTBs (LRBs), polyubiquitinate both Phy and PIFs to be degraded by the 26S proteasome, and consequently photomorphogenesis is initiated. 14-3-3κ is predicted to bind with phosphorylated-PIFs and either escort LRBs to the Phy-PIF complex or stabilize the LRB-Phy-PIF complex to promote PIFs degradation as positive regulators of light signalling.