A significant gap exists in understanding the mechanism of contractile-ring assembly during cytokinesis, which partitions cellular constituents into two new daughter cells and plays a crucial role in cell reproduction and cell differentiation. The long-term goal of our research is to investigate cytokinesis in yeast, in normal somatic and stem cells, as well as in cancer cells. The objective of this application is to investigate the molecular mechanism of the assembly of the contractile ring in fission yeast cytokinesis. The fission yeast Schizosaccharomyces pombe has emerged as one of the leading model systems for the analysis of cytokinesis. Not only is it genetically tractable and favorable for microscopic analysis, but it also has the smallest fully sequenced eukaryotic genome and carries out cytokinesis much like animal cells. Contractile rings consisting of actin filaments, myosin-II motors, and >30 other proteins are essential for cytokinesis in both yeast and animal cells, including humans. The majority of these proteins are conserved during evolution. The central hypothesis of this proposal is that the cytokinetic contractile ring assembles progressively at the cleavage site from a broad band of precursor nodes into a complex protein structure. Actin cross-linking proteins and Polo kinase play essential structural and signaling roles during the assembly. Based on a solid foundation of background research and strong preliminary data, this hypothesis will be tested by investigating three specific aims: 1) Elucidate the roles of the anillin Mid1p in node formation and identify its binding partners in the nodes;2) Establish the roles of actin cross-linking proteins Fimbrin and 1-actinin in coalescing the nodes into the contractile ring;3) Explore the signaling pathways that trigger node formation and node condensation into the contractile ring. A combination of cellular, genetic, biochemical, and confocal microscopic approaches will be employed in these studies. This research is significant because it will reveal how proteins work together during contractile-ring assembly in cytokinesis, and how the anillin Mid1p initiates the assembly of the contractile ring by interacting with evolutionarily conserved structural and signaling proteins. Discerning the assembly of the essential contractile-ring is an important step towards understanding cytokinesis. Additionally, it will help us understand complex actomyosin contractile systems in other cellular processes.
Uncontrolled and misoriented cell divisions are defining characteristics of cancer. Contractile rings, tiny muscle-like force-producing structures, are the common machinery for cytokinesis and other processes including erythrocyte enucleation, morphogenetic epithelial closure, epithelial wound healing, and apoptotic cell extrusion. Thus, much of what we learned about the evolutionarily conserved proteins in cytokinesis is ultimately relevant and applicable to cancer and other human diseases.
|Davidson, Reshma; Liu, Yajun; Gerien, Kenneth S et al. (2016) Real-Time Visualization and Quantification of Contractile Ring Proteins in Single Living Cells. Methods Mol Biol 1369:9-23|
|Wang, Ning; Lee, I-Ju; Rask, Galen et al. (2016) Roles of the TRAPP-II Complex and the Exocyst in Membrane Deposition during Fission Yeast Cytokinesis. PLoS Biol 14:e1002437|
|Davidson, Reshma; Laporte, Damien; Wu, Jian-Qiu (2015) Regulation of Rho-GEF Rgf3 by the arrestin Art1 in fission yeast cytokinesis. Mol Biol Cell 26:453-66|
|Wang, Ning; Wang, Mo; Zhu, Yi-Hua et al. (2015) The Rho-GEF Gef3 interacts with the septin complex and activates the GTPase Rho4 during fission yeast cytokinesis. Mol Biol Cell 26:238-55|
|Sun, Lingfei; Guan, Ruifang; Lee, I-Ju et al. (2015) Mechanistic insights into the anchorage of the contractile ring by anillin and Mid1. Dev Cell 33:413-26|
|Xu, Ting; Vavylonis, Dimitrios; Tsai, Feng-Ching et al. (2015) SOAX: a software for quantification of 3D biopolymer networks. Sci Rep 5:9081|
|Lee, I-Ju; Wang, Ning; Hu, Wen et al. (2014) Regulation of spindle pole body assembly and cytokinesis by the centrin-binding protein Sfi1 in fission yeast. Mol Biol Cell 25:2735-49|
|Coffman, Valerie C; Wu, Jian-Qiu (2014) Every laboratory with a fluorescence microscope should consider counting molecules. Mol Biol Cell 25:1545-8|
|Wang, Ning; Lo Presti, Libera; Zhu, Yi-Hua et al. (2014) The novel proteins Rng8 and Rng9 regulate the myosin-V Myo51 during fission yeast cytokinesis. J Cell Biol 205:357-75|
|Deng, Lin; Kabeche, Ruth; Wang, Ning et al. (2014) Megadalton-node assembly by binding of Skb1 to the membrane anchor Slf1. Mol Biol Cell 25:2660-8|
Showing the most recent 10 out of 26 publications