PAMFGAL · Ancestral molecular function of Polycomb Repressive Complex 2 (PRC2) in green algae lineage

Polycomb-group (PcG) proteins assemble into complexes to maintain cellular identity in multicellular organisms and regulate phase transitions in plants by epigenetic gene repression. Polycomb Repressive Complex 2 (PRC2) is one of the complexes that is evolutionary conserved and catalyzes trimethylation of histone H3 on lysine 27 (H3K27me3). PRC2 is extensively studied in flowering plants, where it determines cell fate during development. Reports predicts putative homologs of PRC2 subunits encoded in the genomes of unicellular green algae but no molecular evidence of PRC2 complex composition, targeting and function is available. The main goal of PAMFGAL project is to describe the molecular functions of PRC2 in the green lineage to elucidate its ancestral roles. It will examine histone modifications in in three trophic states of green algae using ChIP-, RNA- and BS-Sequencing, and determine their impact on the transcription level of genomic elements. By utilizing transgenic algae and complementation of moss coupled with histone modification analysis, the project will investigate PRC2 activity conservation in the green lineage. It will characterize PRC2 complex composition using Co-IP and FRET microscopy. Phenotypic analyses of PRC2 subunit knock-out mutants will elucidate the functional role of PRC2 in growth and reproduction of green algae. Understanding of epigenetic regulation in growth and metabolism of unicellular green algae will contribute to more efficient ingredients production. Rafał Krela will be based in the group of Dr. Iva Mozgova (Biology Center CAS), focused on epigenetic regulation of photoautotrophic development and evolution of the PRCs. Training will involve algae cultivation, bioinformatical analysis, molecular biology and epigenetic methods, and the applicant will take part in leadership and project management training as well. Results will be presented at scientific and industrial conferences, and in high-profile scientific journals.