FIE, a nuclear PRC2 protein, forms cytoplasmic complexes in Arabidopsis thaliana

Moran Oliva, Yana Butenko, Tzung Fu Hsieh, Ofir Hakim, Aviva Katz, Nechama I. Smorodinsky, Daphna Michaeli, Robert L. Fischer, Nir Ohad*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

Polycomb group (PcG) proteins are evolutionarily conserved chromatin modifiers that regulate developmental pathways in plants. PcGs form nuclear multi-subunit Polycomb Repressive Complexes (PRCs). The PRC2 complex mediates gene repression via methylation of lysine 27 on histone H3, which consequently leads to chromatin condensation. In Arabidopsis thaliana, several PRC2 complexes with different compositions were identified, each controlling a particular developmental program. The core subunit FIE is crucial for PRC2 function throughout the plant life cycle, yet accurate information on its spatial and temporal localization was absent. This study focused on identifying FIE accumulation patterns, using microscopy and biochemical approaches. Analysing endogenous FIE and transgenic gFIE-green fluorescent protein fusion protein (gFIE-GFP) showed that FIE accumulates in the nuclei of every cell type examined. Interestingly, gFIE-GFP, as well as the endogenous FIE, also localized to the cytoplasm in all examined tissues. In both vegetative and reproductive organs, FIE formed cytoplasmic high-molecular-mass complexes, in parallel to the nuclear PRC2 complexes. Moreover, size-exclusion chromatography and bimolecular fluorescence complementation assays indicated that in inflorescences FIE formed a cytoplasmic complex with MEA, a PRC2 histone methyltransferase subunit. In contrast, CLF and SWN histone methyltransferases were strictly nuclear. Presence of PRC2 subunits in cytoplasmic complexes has not been previously described in plants. Our findings are in agreement with accumulating evidence demonstrating cytoplasmic localization and function of PcGs in metazoa. The cytosolic accumulation of PRC2 components in plants supports the model that PcGs have alternative non-nuclear functions that go beyond chromatin methylation.

Original languageEnglish
Pages (from-to)6111-6123
Number of pages13
JournalJournal of Experimental Botany
Volume67
Issue number21
DOIs
StatePublished - 1 Nov 2016

Funding

FundersFunder number
Israel Science Foundation574/04, 767/09

    Keywords

    • Cytoplasm
    • FIE
    • MEA
    • PRC2
    • PcG
    • Polycomb complex

    Fingerprint

    Dive into the research topics of 'FIE, a nuclear PRC2 protein, forms cytoplasmic complexes in Arabidopsis thaliana'. Together they form a unique fingerprint.

    Cite this