The DNA damage response (DDR) pathway is a comprehensive and indispensable defensive mechanism present in all eukaryotes. Plants have evolved unique strategies within the DDR to han- dle DNA stress. For instance, the plant-specific NAC (NAM, ATAF1/2 and CUC2) protein SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1) is suspected to replace the mammalian tumor suppressor p53 in its role as key orchestrator of the DDR. Preliminary research detected in vivo formation of an intra- family NAC heterodimer, i.e. SOG1-ANAC044. In a first stage of this research, biophysical characteri- zation of ANAC044 illustrates that, like for SOG1, contact with DNA is transient and non-specific. Al- so, a degree of disorder is present in the conserved NAC domain. In the second stage, the NAC het- erodimer is studied using purified NAC proteins for the first time. Heterodimerization was confirmed independently using direct in vitro pull down experiments and native mass spectrometry. This work contributes to unravel the functionality of NAC heterodimerization, in particular in the context of the plant DDR regulator SOG1.
- Plant cell cycle control
- Structural Biology
- Intrinsically disordered proteins