Key result
The heavy chain carboxyl-terminal domain drives myosin II localization to the MK contractile ring and polyploidization.
Why the study?
The specific role of nonmuscle myosin II isoforms in megakaryocyte polyploidization and contractile ring localization was not fully understood in vivo.
Answers are grounded in this paper and cite their sources.
This in vivo study demonstrates that the carboxyl-terminal domain of heavy chains dictates myosin II localization to the megakaryocyte contractile ring, which is essential for polyploidization.
Endomitosis is a unique megakaryocyte (MK) differentiation process that is the consequence of a late cytokinesis failure associated with a contractile ring defect. Evidence from in vitro studies has revealed the distinct roles of 2 nonmuscle myosin IIs (NMIIs) on MK endomitosis: only NMII-B (MYH10), but not NMII-A (MYH9), is localized in the MK contractile ring and implicated in mitosis/endomitosis transition. Here, we studied 2 transgenic mouse models in which nonmuscle myosin heavy chain (NMHC) II-A was genetically replaced either by II-B or by a chimeric NMHCII that combined the head domain of II-A with the rod and tail domains of II-B. This study provides in vivo evidence on the specific role of NMII-B on MK polyploidization. It demonstrates that the carboxyl-terminal domain of the heavy chains determines myosin II localization to the MK contractile ring and is responsible for the specific role of NMII-B in MK polyploidization.
No takes yet. Share an insight, caveat, or question.
Badirou et al. (2014) studied Megakaryocyte polyploidization. Genetic replacement of NMHC II-A by II-B or a chimeric NMHCII was evaluated on Myosin II localization to the MK contractile ring and role in MK polyploidization. The carboxyl-terminal domain of the heavy chains determines myosin II localization to the megakaryocyte contractile ring and is responsible for the specific role of NMII-B in polyploidization.
Synapse has enriched 10 related papers. Consider them for comparative context: