Focal adhesions control cleavage furrow shape and spindle tilt during mitosis.

Nilay Taneja,Dylan T Burnette,Heidi Hehnly,Bryan A Millis,Lindsay Rathbun,Matthew J Tyska,Aidan M Fenix

doi:10.1038/srep29846

Nilay Taneja, Dylan T Burnette + Show 5 more

Open Access

https://doi.org/10.1038/srep29846

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Abstract

The geometry of the cleavage furrow during mitosis is often asymmetric in vivo and plays a critical role in stem cell differentiation and the relative positioning of daughter cells during development. Early observations of adhesive cell lines revealed asymmetry in the shape of the cleavage furrow, where the bottom (i.e., substrate attached side) of the cleavage furrow ingressed less than the top (i.e., unattached side). This data suggested substrate attachment could be regulating furrow ingression. Here we report a population of mitotic focal adhesions (FAs) controls the symmetry of the cleavage furrow. In single HeLa cells, stronger adhesion to the substrate directed less ingression from the bottom of the cell through a pathway including paxillin, focal adhesion kinase (FAK) and vinculin. Cell-cell contacts also direct ingression of the cleavage furrow in coordination with FAs in epithelial cells—MDCK—within monolayers and polarized cysts. In addition, mitotic FAs established 3D orientation of the mitotic spindle and the relative positioning of mother and daughter centrosomes. Therefore, our data reveals mitotic FAs as a key link between mitotic cell shape and spindle orientation, and may have important implications in our understanding stem cell homeostasis and tumorigenesis.

Highlights

We observed knockdown of vinculin caused a nearly 10-fold increase in ingression from the bottom on the high adhesive substrate (Fig. 2F–G). These findings indicate focal adhesion kinase (FAK) and vinculin regulate cleavage furrow ingression
Our results are highly suggestive of a similar balance existing between contractile forces generated by the ring and adhesive resistive forces generated by cell adhesion to the substrate during mitosis (Fig. 4H)
This model suggests that strong adhesion to the substrate would create high resistance to the contractile force generated by the ring, in turn resulting in asymmetric ingression from the top of the cell

Summary

Introduction

We predicted increasing adhesions with a “high” FN substrate would result in less ingression from the bottom of the cell and, an asymmetrical cleavage furrow. Consistent with reported data for interphase cells, mitotic cells assembled more adhesions and had a greater spread area on the high FN substrate compared to the low FN samples (Fig. 1C, S2C-D).

Results

Conclusion