Single-molecule dynamics of the P granule scaffold MEG-3 in theCaenorhabditis eleganszygote
Year: 2018
Type: article
Abstract: During the asymmetric division of the Caenorhabditis elegans zygote, germ (P) granules are disassembled in the anterior cytoplasm and stabilized/assembled in the posterior cytoplasm, leading to their inheritance by the germline daughter cell. P granule segregation depends on MEG (maternal-effect germline defective)-3 and MEG-4, which are enriched in P granules and in the posterior cytoplasm surrounding P granules. Here we use single-molecule imaging and tracking to characterize the reaction/diffusion mechanisms that result in MEG-3::Halo segregation. We find that the anteriorly enriched RNA-binding proteins MEX (muscle excess)-5 and MEX-6 suppress the retention of MEG-3 in the anterior cytoplasm, leading to MEG-3 enrichment in the posterior. We provide evidence that MEX-5/6 may work in conjunction with PLK-1 kinase to suppress MEG-3 retention in the anterior. Surprisingly, we find that the retention of MEG-3::Halo in the posterior cytoplasm surrounding P granules does not appear to contribute significantly to the maintenance of P granule asymmetry. Rather, our findings suggest that the formation of the MEG-3 concentration gradient and the segregation of P granules are two parallel manifestations of MEG-3's response to upstream polarity cues.
Source: Molecular Biology of the Cell
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: Consequences and Control of Randomness in Timing of Intracellular, MRI: Acquisition of Nikon A1RSi Confocal Microscope with Hybrid Scanner, Spectral Unmixing and FLIM/FCS, Stochastic hybrid systems approach to uncovering cell-size control mechanisms , Mechanisms of Spatial Organization in the Cytoplasm, TIRFM-imaging system for in vitro and in vivo cell biology
OpenAlex ID: W2905150895