TY - JOUR
T1 - Competition between tropomyosin, fimbrin, and ADF/cofilin drives their sorting to distinct actin filament networks
AU - Christensen, Jenna R.
AU - Hocky, Glen M.
AU - Homa, Kaitlin E.
AU - Morganthaler, Alisha N.
AU - Hitchcock-Degregori, Sarah E.
AU - Voth, Gregory A.
AU - Kovar, David R.
N1 - Funding Information:
This work was supported by NIH R01 GM079265 and ACS RSG-11-126-01-CSM (to DRK), NIH MCB Training Grant T32 GM0071832 (to JRC and KEH), NSF Graduate Student Fellowship DGE-1144082 (to JRC), NIH Ruth L Kirschstein NRSA F32 GM113415-01 (to GMH) and NIH R01 GM093965 (to SEH-D). Additional support was provided to DRK and GAV by the University of Chicago MRSEC, funded by the NSF through grant DMR-1420709. We thank Ben Glick and GSL Biotech for the use of SnapGene for plasmid construction, and DJ Speed for assistance with cloning of Adf1 mutants. We also thank Suri Vaikuntanathan, the Kovar lab, and the Voth lab for helpful discussions. National Institutes of Health GM079265 David R Kovar American Cancer Society RSG-11-126-01-CSM David R Kovar National Science Foundation DGE-1144082 Jenna R Christensen National Institutes of Health T32 GM0071832 Jenna R Christensen Kaitlin E Homa National Institutes of Health F32 GM113415-01 Glen M Hocky National Institutes of Health GM093965 Sarah E Hitchcock-DeGregori National Science Foundation DMR-1420709 Gregory A Voth David R Kovar The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Publisher Copyright:
© Christensen et al.
PY - 2017/3/10
Y1 - 2017/3/10
N2 - The fission yeast actin cytoskeleton is an ideal, simplified system to investigate fundamental mechanisms behind cellular self-organization. By focusing on the stabilizing protein tropomyosin Cdc8, bundling protein fimbrin Fim1, and severing protein coffin Adf1, we examined how their pairwise and collective interactions with actin filaments regulate their activity and segregation to functionally diverse F-actin networks. Utilizing multi-color TIRF microscopy of in vitro reconstituted F-actin networks, we observed and characterized two distinct Cdc8 cables loading and spreading cooperatively on individual actin filaments. Furthermore, Cdc8, Fim1, and Adf1 all compete for association with F-actin by different mechanisms, and their cooperative association with actin filaments affects their ability to compete. Finally, competition between Fim1 and Adf1 for F-actin synergizes their activities, promoting rapid displacement of Cdc8 from a dense F-actin network. Our findings reveal that competitive and cooperative interactions between actin binding proteins help define their associations with different F-actin networks.
AB - The fission yeast actin cytoskeleton is an ideal, simplified system to investigate fundamental mechanisms behind cellular self-organization. By focusing on the stabilizing protein tropomyosin Cdc8, bundling protein fimbrin Fim1, and severing protein coffin Adf1, we examined how their pairwise and collective interactions with actin filaments regulate their activity and segregation to functionally diverse F-actin networks. Utilizing multi-color TIRF microscopy of in vitro reconstituted F-actin networks, we observed and characterized two distinct Cdc8 cables loading and spreading cooperatively on individual actin filaments. Furthermore, Cdc8, Fim1, and Adf1 all compete for association with F-actin by different mechanisms, and their cooperative association with actin filaments affects their ability to compete. Finally, competition between Fim1 and Adf1 for F-actin synergizes their activities, promoting rapid displacement of Cdc8 from a dense F-actin network. Our findings reveal that competitive and cooperative interactions between actin binding proteins help define their associations with different F-actin networks.
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U2 - 10.7554/eLife.23152
DO - 10.7554/eLife.23152
M3 - Article
C2 - 28282023
AN - SCOPUS:85018302147
SN - 2050-084X
VL - 6
JO - eLife
JF - eLife
M1 - e23152
ER -