A SMG7-eIF4A module constitutes a homeostatic system for P-bodies and Meiotic bodies

The nucleation of RNP granules requires the participation of mRNAs, which simultaneously as becoming their target, dictate their properties. Here we report that in Arabidopsis the RNA helicase eIF4A limits the condensation of P-bodies acting as an RNA chaperone, disassembled from the eIF4F complex. eIF4A is recruited into P-bodies by SMG7, previously known to recruit UPF1 and TDM1. In response to heat shock (HS) eIF4A shares distribution within stress granules (SGs) and P-bodies, modulating the condensation of both RNP granules. Our study of meiotic RNP granules demonstrates the nucleation of the meiotic body (M-body), constituted by a P-body core and a SGs surrounding shell. SMG7 recruits eIF4A in the M-body core to modulate its condensation, which impacts the functionality of this body an influence plant reproduction. We conclude that SMG7 governs the functionality of P-bodies and M-bodies, and with eIF4A, constitutes a homeostatic system to control their level of condensation