AI Article Synopsis
- Cytokinesis starts during anaphase with the activation of RhoA, leading to the formation of a contractile ring at the cell's center.
- Research identifies two pathways for starting cleavage furrow formation: one relies on a properly organized spindle midzone and PLK1, while the other operates through Aurora B and centralspindlin, independent of PLK1.
- PLK1 helps release centralspindlin from the spindle midzone, allowing it to activate RhoA at the cell's equatorial cortex, crucial for successful cell division.
Article Abstract
Cytokinesis begins upon anaphase onset. An early step involves local activation of the small GTPase RhoA, which triggers assembly of an actomyosin-based contractile ring at the equatorial cortex. Here, we delineated the contributions of PLK1 and Aurora B to RhoA activation and cytokinesis initiation in human cells. Knock-down of PRC1, which disrupts the spindle midzone, revealed the existence of two pathways that can initiate cleavage furrow ingression. One pathway depends on a well-organized spindle midzone and PLK1, while the other depends on Aurora B activity and centralspindlin at the equatorial cortex and can operate independently of PLK1. We further show that PLK1 inhibition sequesters centralspindlin onto the spindle midzone, making it unavailable for Aurora B at the equatorial cortex. We propose that PLK1 activity promotes the release of centralspindlin from the spindle midzone through inhibition of PRC1, allowing centralspindlin to function as a regulator of spindle midzone formation and as an activator of RhoA at the equatorial cortex.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6446842 | PMC |
| http://dx.doi.org/10.1083/jcb.201805036 | DOI Listing |
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