最近,，Michigan州立大學(xué)和Van Andel研究所的研究人員從事的人類(lèi)細(xì)胞繁殖的研究，其研究報(bào)告或許能使科學(xué)家距離找到癌癥的“關(guān)閉”開(kāi)關(guān)更近一步,。該研究報(bào)告發(fā)表在最近出版的《生物化學(xué)雜志》（Journal of Biological Chemistry，JBC）上,。
癌細(xì)胞能夠無(wú)限地分裂增殖,，并能在機(jī)體中發(fā)生轉(zhuǎn)移，在這個(gè)過(guò)程中,，癌細(xì)胞的形狀發(fā)生改變,。研究人員DeWard及其同事發(fā)現(xiàn)一種命名為formins的蛋白質(zhì)在細(xì)胞分裂和移動(dòng)時(shí)能夠決定細(xì)胞的形狀，并發(fā)現(xiàn)了細(xì)胞分裂時(shí)formins的調(diào)節(jié)機(jī)制,。
目前,，針對(duì)這類(lèi)蛋白質(zhì)如何啟動(dòng)相關(guān)功能有大量的相關(guān)研究,，但如何關(guān)閉這類(lèi)蛋白質(zhì)家族的功能還不清楚。因此,，該課題的研究人員提供了旨在找到能特異性關(guān)閉無(wú)限增殖的癌細(xì)胞的分子機(jī)制,。
DeWard說(shuō)，雖然關(guān)閉細(xì)胞分裂過(guò)程并不意味著能夠阻止癌癥的發(fā)生,，但了解相關(guān)分子機(jī)制能夠使研究人員找到更好地控制癌癥發(fā)生的途徑,。（生物谷Bioon.com）
生物谷推薦原始出處：
J. Biol. Chem., Vol. 284, Issue 30, 20061-20069, July 24, 2009
Ubiquitin-mediated Degradation of the Formin mDia2 upon Completion of Cell Division*
Aaron D. DeWard and Arthur S. Alberts1
From the From the Laboratory of Cell Structure and Signal Integration, Van Andel Research Institute, Grand Rapids, Michigan 49503 and , the Program in Cell and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
ABSTRACT
Formins assemble non-branched actin filaments and modulate microtubule dynamics during cell migration and cell division. At the end of mitosis formins contribute to the generation of actin filaments that form the contractile ring. Rho small GTP-binding proteins activate mammalian diaphanous-related (mDia) formins by directly binding and disrupting an intramolecular autoinhibitory mechanism. Although the Rho-regulated activation mechanism is well characterized, little is known about how formins are switched off. Here we reveal a novel mechanism of formin regulation during cytokinesis based on the following observations; 1) mDia2 is degraded at the end of mitosis, 2) mDia2 is targeted for disposal by post-translational ubiquitin modification, 3) forced expression of activated mDia2 yields binucleate cells due to failed cytokinesis, and 4) the cytokinesis block is dependent upon mDia2-mediated actin assembly as versions of mDia2 incapable of nucleating actin but that still stabilize microtubules have no effect on cytokinesis. We propose that the tight control of mDia2 expression and ubiquitin-mediated degradation is essential for the completion of cell division. Because of the many roles for formins in cell morphology, we discuss the relevance of mDia protein turnover in other processes where ubiquitin-mediated proteolysis is an essential component.
