To evaluate a possible transmission of polarity from cytoskeleton to nucleus we needed a cell population with a clear front-rear polarity in which to test this hypothesis. Our findings reveal that the asymmetric organization of the cell can be transmitted to the nucleus. To that end, we systematically and quantitatively study spatial distribution of various components in front-to-rear polarized cells. However, it has not been further investigated how much this impacts other nuclear envelope (NE) proteins or the nuclear interior.Īs it has been previously shown that the nucleus exhibits radial organization 8, 9, in this study, we aim to analyze it along the front-to-rear axis. Seminal studies reported a tension-induced basal-to-apical polarization of lamin A/C in mouse embryonic fibroblasts 6, 7. However, it is still unknown if and how front-rear polarity of a cell is transmitted to the largest cellular organelle, the nucleus. It also parallelizes the polarization of intracellular compartments as well as signaling cascades 3. This so-called, front-rear polarity is essential and dictates the direction of movement 4, 5. Various migratory cell types display a characteristic morphology with a protruding front, at the opposite of a retracting trailing edge 3. Particularly, migration is a fundamentally polarized process that requires the organization of the cell machinery along a front-to-rear axis. Cellular polarity is crucial in many biological processes, such as morphogenesis, differentiation, proliferation, and migration 2. It is manifested in cell shape and structure as well as distribution of proteins and cellular organelles. Our results demonstrate that front-rear cell polarity is transmitted to the nucleus and that emerin is an important determinant of nuclear polarity.Ĭell polarity is defined as an intrinsic asymmetry observed in the structural orientation of the cytoskeleton, mainly due to actin filaments and microtubules 1. In primary emerin-deficient myoblasts, its expression partially rescues the polarity of the nucleus. We propose that the frontally biased localization of the endoplasmic reticulum, through which emerin reaches the nuclear envelope, is sufficient to generate its observed bias.
We show that the knock-down of emerin, an integral protein of the nuclear envelope, abolishes preferential localization of several nuclear proteins. While the link between the cytoskeleton and nucleus is well-studied, we aim to investigate if front-rear polarity can be transmitted to the nucleus. In migratory cells, front-rear polarity is essential and dictates movement direction. It affects cell shape and structure as well as the distribution of proteins and organelles. Cell polarity refers to the intrinsic asymmetry of cells, including the orientation of the cytoskeleton.
0 kommentar(er)
