Abstract: Once again the FEBS Letters Award Committee was able to identify and select a remarkable young Group Leader, who published an outstanding article in FEBS Letters, for the 2011 FEBS Letters Young Group Leader Award. Though several other studies of great interest and scientific quality competed closely for the prize, the final decision was unanimous. The 10,000€ award was assigned to Dr. Shiro Suetsugu from the University of Tokyo, Japan, for the article entitled “Mapping of the basic amino-acid residues responsible for tubulation and cellular protrusion by the EFC/F-BAR domain of Pacsin2/Syndapin II” [1]. The committee praised the manuscript for its multidisciplinary approaches bridging structural biology and functional studies while embracing the atomic and cellular level. Dr. Suetsugu and his team provided fundamental new insights into the molecular mechanisms governing the plasticity of biological membranes and specifically into the formation of cellular microspikes and tubules. We have interviewed Dr. Suetsugu in order to offer you a more personal perspective of his work and life in Tokyo. We propose a novel function for the concave surface of the EFC/F-BAR domain of Pacsin2/Syndapin II. BAR domain proteins are membrane adapters that are able to shape membranes into tubules or protrusions. We solved the structure of Pacsin2, which has the typical banana shape of F-BAR domain proteins, whereby the positively charged concave surface of the protein binds to the negatively charged inner surface of the membrane. Pacsin2 is known to wrap around the emerging tubule, bending and shaping the membrane as the tubule forms. However, our localization analyses showed that Pacsin2 also adhered to the neck of membrane protrusions (or microspikes), where the curvature of the membrane is convex. This implies that Pacsin2 has a role in promoting microspike formation by bending the membrane at the neck (Fig. 1 ). We mapped the basic amino acids and hydrophobic loops that are essential for tubulation and microspike formation. We also show that treatment with latrunculin (an actin depolymerising agent) suppresses formation of microspikes, while it promotes tubulation. We concluded that actin polymerization is necessary for the elongation of the microspike, while Pacsin2 bends the membrane at the neck. Tubules, on the other hand, do not protrude and do not need (or may even be suppressed by) actin filaments, though they require Pacsin2 for invagination. Right now we are exploring the role of Pacsin in the formation of caveolae during endocytosis. On the whole, BAR-domain proteins are involved in a variety of cellular functions that involve membrane deformation. The structural aspect of the F-BAR domain had just been published in two different studies [2, 3]. However, we had novel functional insights that went beyond these two publications. We needed to publish our findings rapidly due to competition with other labs, so we chose FEBS Letters. An additional advantage was that publication is completely free of charge in FEBS Letters. Thankfully, my family and neighbours are all well. However, in the areas struck by the tsunami, approximately 200-400 Km north of Tokyo, people are struggling to recover. I visited those areas and couldn't help feeling in low spirits. Once the roads were cleared, my friends and I travelled to the house of the parents of friends that had been damaged by the tsunami. We all helped to clean up and fix what we could. Many people are helping this way, and the good side is that this brings us closer together and creates stronger bonds between us. We know that we can count on each other. The earthquake and tsunami affected our daily lives in many ways. All the transport connections were blocked and the delivery of goods was delayed. However, from that point of view the situation is gradually improving. Our main concern at the moment is the trouble with the nuclear power plant in Fukushima, which is likely to produce long-term effects. The contaminated territories are out of bounds, and they may not recover as easily. The area will probably not be repopulated, and we are waiting for the government to decide what to do with it. In March, we suffered scheduled power cuts in Tokyo, especially during the cold days immediately after the accident, when more energy was necessary for heating. At the institute and at home we adopted a power-saving plan. This has taught us to use less energy and to live more ecologically. People here, including me, are worried about the potential risk of the contamination, though it seems that in some parts of Europe people are protesting against nuclear energy a lot more than we do in Japan. Before the earthquake, nuclear energy was strongly promoted to cut CO2 emissions, but I doubt that new nuclear power plants will be built in Japan in the future. Novel resources will have to be discussed now. Hopefully, we will switch to cleaner sources of energy. Above all, I try to look at experimental data without a bias. When we plan an experiment and have a hypothesis in mind, we should always ask ourselves what the phenotype should be if the hypothesis is correct. Only then we can notice unexpected differences. For example, in my former lab, we came across BAR domain proteins through a protein interaction study in which we were looking for proteins interacting with N-WASP, which is known to mediate actin polymerization. At the time, the function of BAR domain proteins was unknown. However, when expressing the proteins in cells for the interaction study, we realized that the star-like localization of F-BAR was actually membrane invagination induced by F-BAR via direct protein-phospholipid interaction [4]. In a similar way, we noticed that the membrane protrusions induced by I-BAR overexpression could be due to membrane deformation [5]. Needless to say, discussions with colleagues and with supervisors or experts in the field were crucial to this regard. The core of research may be a significantly personalized affair, but we are always grateful to people who helped us in various ways. In a nutshell, it is essential to be open-minded and not to dismiss any detail. Email address: [email protected] Interview by Daniela Ruffell