Limits...
Hof1 and Rvs167 have redundant roles in actomyosin ring function during cytokinesis in budding yeast.

Nkosi PJ, Targosz BS, Labib K, Sanchez-Diaz A - PLoS ONE (2013)

Bottom Line: This new function of Rvs167 appears to be independent of its known role as a regulator of the Arp2/3 actin nucleator, as actin ring assembly is not abolished by the simultaneous inactivation of Hof1 and Arp2/3.Instead we find that recruitment to the bud-neck of the Iqg1 actin regulator is defective in cells lacking Hof1 and Rvs167, though future studies will be needed to determine if this reflects a direct interaction between these factors.The redundant role of Hof1 in actin ring assembly suggests that the mechanism of actin ring assembly has been conserved to a greater extent across evolution than anticipated previously.

View Article: PubMed Central - PubMed

Affiliation: Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom.

ABSTRACT
The Hof1 protein (Homologue of Fifteen) regulates formation of the primary septum during cytokinesis in the budding yeast Saccharomyces cerevisiae, whereas the orthologous Cdc15 protein in fission yeast regulates the actomyosin ring by using its F-BAR domain to recruit actin nucleators to the cleavage site. Here we show that budding yeast Hof1 also contributes to actin ring assembly in parallel with the Rvs167 protein. Simultaneous deletion of the HOF1 and RVS167 genes is lethal, and cells fail to assemble the actomyosin ring as they progress through mitosis. Although Hof1 and Rvs167 are not orthologues, they both share an analogous structure, with an F-BAR or BAR domain at the amino terminus, capable of inducing membrane curvature, and SH3 domains at the carboxyl terminus that bind to specific proline-rich targets. The SH3 domain of Rvs167 becomes essential for assembly of the actomyosin ring in cells lacking Hof1, suggesting that it helps to recruit a regulator of the actin cytoskeleton. This new function of Rvs167 appears to be independent of its known role as a regulator of the Arp2/3 actin nucleator, as actin ring assembly is not abolished by the simultaneous inactivation of Hof1 and Arp2/3. Instead we find that recruitment to the bud-neck of the Iqg1 actin regulator is defective in cells lacking Hof1 and Rvs167, though future studies will be needed to determine if this reflects a direct interaction between these factors. The redundant role of Hof1 in actin ring assembly suggests that the mechanism of actin ring assembly has been conserved to a greater extent across evolution than anticipated previously.

Show MeSH
Recruitment of Iqg1 to the bud-neck is defective in cells lacking Hof1 and Rvs167.(A) Cells were processed as described above for Figure 4, so that the recruitment of GFP-Iqg1 to the bud-neck (i) could be monitored as cells passed through mitosis (ii). (B) Images from the experiment described in (A). The scale bars correspond to 2 µm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3585203&req=5

pone-0057846-g007: Recruitment of Iqg1 to the bud-neck is defective in cells lacking Hof1 and Rvs167.(A) Cells were processed as described above for Figure 4, so that the recruitment of GFP-Iqg1 to the bud-neck (i) could be monitored as cells passed through mitosis (ii). (B) Images from the experiment described in (A). The scale bars correspond to 2 µm.

Mentions: Finally, we examined the recruitment of Iqg1 to the bud-neck in cells lacking Hof1 and Rvs167, in similar experiments to those described above. Whereas Iqg1 was found at the bud-neck during mitosis in control and hof1-td cells, recruitment of Iqg1 was very defective, though not completely abolished, in hof1-td rvs167Δ and hof1-td rvs167-ΔSH3 (Figure 7).


Hof1 and Rvs167 have redundant roles in actomyosin ring function during cytokinesis in budding yeast.

Nkosi PJ, Targosz BS, Labib K, Sanchez-Diaz A - PLoS ONE (2013)

Recruitment of Iqg1 to the bud-neck is defective in cells lacking Hof1 and Rvs167.(A) Cells were processed as described above for Figure 4, so that the recruitment of GFP-Iqg1 to the bud-neck (i) could be monitored as cells passed through mitosis (ii). (B) Images from the experiment described in (A). The scale bars correspond to 2 µm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585203&req=5

pone-0057846-g007: Recruitment of Iqg1 to the bud-neck is defective in cells lacking Hof1 and Rvs167.(A) Cells were processed as described above for Figure 4, so that the recruitment of GFP-Iqg1 to the bud-neck (i) could be monitored as cells passed through mitosis (ii). (B) Images from the experiment described in (A). The scale bars correspond to 2 µm.
Mentions: Finally, we examined the recruitment of Iqg1 to the bud-neck in cells lacking Hof1 and Rvs167, in similar experiments to those described above. Whereas Iqg1 was found at the bud-neck during mitosis in control and hof1-td cells, recruitment of Iqg1 was very defective, though not completely abolished, in hof1-td rvs167Δ and hof1-td rvs167-ΔSH3 (Figure 7).

Bottom Line: This new function of Rvs167 appears to be independent of its known role as a regulator of the Arp2/3 actin nucleator, as actin ring assembly is not abolished by the simultaneous inactivation of Hof1 and Arp2/3.Instead we find that recruitment to the bud-neck of the Iqg1 actin regulator is defective in cells lacking Hof1 and Rvs167, though future studies will be needed to determine if this reflects a direct interaction between these factors.The redundant role of Hof1 in actin ring assembly suggests that the mechanism of actin ring assembly has been conserved to a greater extent across evolution than anticipated previously.

View Article: PubMed Central - PubMed

Affiliation: Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom.

ABSTRACT
The Hof1 protein (Homologue of Fifteen) regulates formation of the primary septum during cytokinesis in the budding yeast Saccharomyces cerevisiae, whereas the orthologous Cdc15 protein in fission yeast regulates the actomyosin ring by using its F-BAR domain to recruit actin nucleators to the cleavage site. Here we show that budding yeast Hof1 also contributes to actin ring assembly in parallel with the Rvs167 protein. Simultaneous deletion of the HOF1 and RVS167 genes is lethal, and cells fail to assemble the actomyosin ring as they progress through mitosis. Although Hof1 and Rvs167 are not orthologues, they both share an analogous structure, with an F-BAR or BAR domain at the amino terminus, capable of inducing membrane curvature, and SH3 domains at the carboxyl terminus that bind to specific proline-rich targets. The SH3 domain of Rvs167 becomes essential for assembly of the actomyosin ring in cells lacking Hof1, suggesting that it helps to recruit a regulator of the actin cytoskeleton. This new function of Rvs167 appears to be independent of its known role as a regulator of the Arp2/3 actin nucleator, as actin ring assembly is not abolished by the simultaneous inactivation of Hof1 and Arp2/3. Instead we find that recruitment to the bud-neck of the Iqg1 actin regulator is defective in cells lacking Hof1 and Rvs167, though future studies will be needed to determine if this reflects a direct interaction between these factors. The redundant role of Hof1 in actin ring assembly suggests that the mechanism of actin ring assembly has been conserved to a greater extent across evolution than anticipated previously.

Show MeSH