Molecular basis of Arabidopsis ESCRT protein function in the nucleus

• Applicant: Professorin Dr. Erika Isono
• Subject Area: Plant Cell and Developmental Biology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 569041930

The role of the endosomal sorting complexes required for transport (ESCRTs) has been intensively studied in the ubiquitin-dependent endosomal degradation of plasma membrane proteins, particularly in the formation of intraluminal vesicles (ILVs) at the multivesicular endosomes (MVEs). Recent studies in opisthokonts have shown that ESCRTs are also involved in membrane fission events topologically similar to ILV formation such as autophagosome maturation and nuclear envelope (NE) reformation. Plant cells undergo open mitosis, in which the NE has to collapse and reforms during the progression of the cell cycle. In opisthokonts, the LEM domain-containing protein LEM2 has been shown to interact with an ESCRT protein CHMP7 and to play a key role in the recruitment of ESCRTs to the NE. Although some of the factors that function with ESCRT components in non-endosomal contexts are also present in plants, many, including LEM2 and BAF, are not found in the Arabidopsis genome. With a focus on CHMP7 and its interactors, the project aims to understand the involvement of ESCRTs in NE sealing using the model plant Arabidopsis thaliana. The goals are to identify the molecular network recruiting CHMP7 and further ESCRT-III components at the nucleus, to elucidate the molecular mechanisms underlying the endosomal and nuclear recruitment of ESCRT-III proteins, and to understand the impact of ESCRTs on the formation and maintenance of plant nuclei.

• DFG Programme: Research Grants