Dual function of MIPS1 as a metabolic enzyme and transcriptional regulator.

David Latrasse , Teddy Jégu , Pin-Hong Meng , Christelle Mazubert (1) , Elodie Hudik , Marianne Delarue , Céline Charon (2) , Martin Crespi (1) , Heribert Hirt , Cécile Raynaud (1) , Catherine Bergounioux (1) , Moussa Benhamed

1 ISV - Institut des sciences du végétal
2 CNG - Centre National de Génotypage

Because regulation of its activity is instrumental either to support cell proliferation and growth or to promote cell death, the universal myo-inositol phosphate synthase (MIPS), responsible for myo-inositol biosynthesis, is a critical enzyme of primary metabolism. Surprisingly, we found this enzyme to be imported in the nucleus and to interact with the histone methyltransferases ATXR5 and ATXR6, raising the question of whether MIPS1 has a function in transcriptional regulation. Here, we demonstrate that MIPS1 binds directly to its promoter to stimulate its own expression by locally inhibiting the spreading of ATXR5/6-dependent heterochromatin marks coming from a transposable element. Furthermore, on activation of pathogen response, MIPS1 expression is reduced epigenetically, providing evidence for a complex regulatory mechanism acting at the transcriptional level. Thus, in plants, MIPS1 appears to have evolved as a protein that connects cellular metabolism, pathogen response and chromatin remodeling.

Mots clés: PROGRAMMED CELL-DEATH; GENE-EXPRESSION; ARABIDOPSIS-THALIANA; DEFENSE RESPONSES; MYOINOSITOL; METHYLATION; RESISTANCE

Mots clés: PLANT IMMUNE-SYSTEM; DNA; PROTEINS

Domaines: Biologie végétale

David Latrasse, Teddy Jégu, Pin-Hong Meng, Christelle Mazubert, Elodie Hudik, et al.. Dual function of MIPS1 as a metabolic enzyme and transcriptional regulator.. Nucleic Acids Research, 2013, 41 (5), pp.2907-17. ⟨10.1093/nar/gks1458⟩. ⟨hal-00856166⟩