Mechanisms underlying functional redundancy of plant CRWN proteins

• Applicant: Professor Dr. Chang Liu
• Subject Area: Plant Genetics and Genomics
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 524743627

In the plant kingdom, nuclear matrix constituent proteins (NMCPs) function as nuclear lamin analogs, which regulate nuclear morphology and perinuclear chromatin tethering. They are also involved in gene expression regulation via interacting with transcription factors and chromatin remodelers. Previous genetic studies have revealed that the four NMCPs in Arabidopsis, named CROWDED NUCLEI (CRWN), are vital for plants to complete their life cycle. However, among these CRWNs, only CRWN1 has been intensively studied. How CRWNs functionally complement each other on a molecular level is poorly understood. In our recent experiments, we examined crwn1 crwn2 crwn4 triple mutants at a seedling stage, which show severe growth defects compared to double mutants. RNA-seq analyses indicate that the triple mutants resemble wild-type plants that were under pathogen attack. Interestingly, we found that CRWN2 proteins display distinct nuclear localization patterns in different genetic backgrounds. In wild-type plants, CRWN2 proteins formed speckles that were distributed evenly in the nucleoplasm, but they became specifically localized at the nuclear periphery in crwn1 crwn4 double mutants. Following this finding, in this project, by employing cutting-edge genomic and proteomic methods, we aim to investigate the molecular mechanisms determining CRWN2’s specific perinuclear localization. We also aim to gain a better understanding of how CRWN2 covers the loss of CRWN1 and CRWN4 at the nuclear periphery.

• DFG Programme: Research Grants