Key result
The myo2-S1 myosin II mutant allele rescued lethality caused by compromised actin cable and ring assembly mechanisms in fission yeast, suggesting a role for myosin II in actin filament disassembly.
Why the study?
The mechanisms controlling the assembly, stability, and turnover of the eukaryotic actin cytoskeleton are key to its cellular functions.
This study provides in vivo evidence that myosin II plays a role in actin filament disassembly and turnover in fission yeast.
No clinical implications for cardiology; hypothesis-generating for myosin II in actin turnover, needing mammalian validation.
The actin cytoskeleton plays a variety of roles in eukaryotic cell physiology, ranging from cell polarity and migration to cytokinesis. Key to the function of the actin cytoskeleton is the mechanisms that control its assembly, stability, and turnover. Through genetic analyses in fission yeast, we found that, myo2-S1 ( myo2 -G515D), a myosin II mutant allele was capable of rescuing lethality caused by compromise of mechanisms involved in actin cable / ring assembly and stability. The mutation in myo2 -S1 affects the activation loop of Myosin II, which is involved in physical interaction with subdomain 1 of actin and in stimulating the ATPase activity of Myosin. Consistently, actomyosin rings in myo2 -S1 cell ghosts were severely compromised in contraction upon ATP addition, suggesting that Myo2-S1p was defective in actin binding and / or motor activity. These studies strongly suggest a role for Myo2p in actin cytoskeletal disassembly and turnover, and that compromise of this activity leads to genetic suppression of mutants defective in actin cable assembly / stability.
No takes yet. Share an insight, caveat, or question.
Zambon et al. (2020) studied this question. myo2-S1 mutation vs. wild-type and cdc3-124 mutants was evaluated on Rescue of lethality caused by cdc3-124 mutation at restrictive temperatures. The myo2-S1 myosin II mutant allele rescued lethality caused by compromised actin cable and ring assembly mechanisms in fission yeast, suggesting a role for myosin II in actin filament disassembly.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: