Publication details
The SMG7-eIF4A module constitutes a homeostatic system for P-bodies and Meiotic bodies
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| Year of publication | 2025 |
| Type | Conference abstract |
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| Description | Ribonucleoprotein (RNP) condensates, such as stress granules (SGs) and P-bodies, serve as dynamic hubs for regulating mRNA processing and storage. Their nucleation involves RNA molecules engaging in multivalent interactions with other RNAs and proteins. While biomolecular condensates generally tend to fuse and coalesce into larger structures, this growth is restricted by several mechanisms. Among these are RNA helicases, which function as RNA chaperones to modulate RNA interactions and are thus implicated in RNP granule condensation, fluidity and size homeostasis. However, the physiological importance of these processes remain largely unexplored, and no such mechanisms have been described in plants. Here, we report that the DEAD-box RNA helicase eIF4A, a subunit of the key translation initiation factor eIF4F, plays a previously unrecognized role in limiting the condensation of P-bodies. eIF4A is recruited into P-bodies by SMG7, an adaptor protein known for its role in nonsense-mediated RNA decay. In response to heat shock, eIF4A is distributed between SGs and P-bodies, and modulates their condensation. Our study of meiotic RNP granules reveals the nucleation of the meiotic body (M-body), which consists of a P-body core surrounded by an SG shell. SMG7 recruits eIF4A into the M-body core, modulating its condensation, which in turn affects the functionality of this structure and influences plant reproduction. We conclude that SMG7 governs the composition and functionality of P-bodies and M-bodies and, together with eIF4A, forms a homeostatic system that regulates their level of condensation. |