生物谷報導：細胞膜遠不止是細胞外的一層包裹物，對其拓撲進行的重塑研究，將它們與內吞作用、囊泡形成和蛋白分選等重要功能聯繫了起來。專門的蛋白能夠感知和生成膜曲率，指導膜的重塑。幾種蛋白需要一起發揮作用才能完成這一任務，所以一種比較普遍的效應被認為也在發揮作用。多年來，物理學家、數學家、材料科學家和細胞生物學家對一種可能的普遍作用——完全由膜曲率誘導的蛋白之間的吸引力進行了研究。但是，誘導蛋白間相互作用的膜曲率的性質，甚至它們之間的相互作用是吸引還是排斥都仍然比較模糊。現在，計算機模擬顯示，曲率誘導的相互作用的確可以是一種吸引力，並且是強大的、很有力的吸引力，完全能夠勝任影響膜重塑的任務。本期封面圖片所示為一個在協同分裂期間被衣殼所覆蓋的虛擬細胞膜。
英文原文：
Letter
Nature 447, 461-464 (24 May 2007) | doi:10.1038/nature05840; Received 23 October 2006; Accepted 11 April 2007
Benedict J. Reynwar1, Gregoria Illya1, Vagelis A. Harmandaris1, Martin M. Müller1, Kurt Kremer1 & Markus Deserno1
Correspondence to: Kurt Kremer1Markus Deserno1 Correspondence and requests for materials should be addressed to M.D. (Email: deserno@mpip-mainz.mpg.de) or K.K. (Email: kremer@mpip-mainz.mpg.de).
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of pageMembrane remodelling1, 2, 3, 4, 5 plays an important role in cellular tasks such as endocytosis, vesiculation and protein sorting, and in the biogenesis of organelles such as the endoplasmic reticulum or the Golgi apparatus. It is well established that the remodelling process is aided by specialized proteins that can sense4 as well as create6 membrane curvature, and trigger tubulation7, 8, 9 when added to synthetic liposomes. Because the energy needed for such large-scale changes in membrane geometry significantly exceeds the binding energy between individual proteins and between protein and membrane, cooperative action is essential. It has recently been suggested10, 11 that curvature-mediated attractive interactions could aid cooperation and complement the effects of specific binding events on membrane remodelling. But it is difficult to experimentally isolate curvature-mediated interactions from direct attractions between proteins. Moreover, approximate theories predict repulsion between isotropically curving proteins12, 13, 14, 15. Here we use coarse-grained membrane simulations to show that curvature-inducing model proteins adsorbed on lipid bilayer membranes can experience attractive interactions that arise purely as a result of membrane curvature. We find that once a minimal local bending is realized, the effect robustly drives protein cluster formation and subsequent transformation into vesicles with radii that correlate with the local curvature imprint. Owing to its universal nature, curvature-mediated attraction can operate even between proteins lacking any specific interactions, such as newly synthesized and still immature membrane proteins in the endoplasmic reticulum.
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