Cryo-electron microscopy and computer simulations of mitochondrial complex I
The respiratory chain plays a central role in energy metabolism of the cell. It is localized in mitochondria, the cell´s own power plants. In a new study, researchers from Goethe University, the Max Planck Institute of Biophysics and the University of Helsinki have determined the high-resolution structure of a central component of the respiratory chain, mitochondrial complex I, and simulated its dynamics on the computer. These findings both support basic research and enhance our understanding of certain neuromuscular and neurodegenerative diseases that are linked with mitochondrial dysfunction.
FRANKFURT. All vital processes require a constant supply of energy. In the cell, the chemically “charged" molecule ATP is the main provider of this energy. The ATP power packs are produced, among others, in specialised small organs (“organelles") of the cell, the mitochondria.
There, the protein complexes of the respiratory chain pump hydrogen ions (protons with a positive charge) from one side of the inner mitochondrial membrane to the other (“uphill"), creating a chemical concentration gradient and an electrical voltage. The protons “flow downhill" along this electrochemical gradient through a kind of turbine that generates useful energy for the cell in the form of ATP.
One of the proton pumps in the first step of the process is a large, L-shaped biomolecule, mitochondrial complex I (in short: complex I). Its horizontal arm is anchored in the membrane. The vertical arm binds the electron carrier molecule NADH, which is produced during metabolic breakdown of sugar and other nutrients. Complex I catalyses the transfer of electrons from NADH to ubiquinone (Q10), and the energy released in this reaction is used to drive the proton pump.
The research team from Goethe University and the Max Planck Institute of Biophysics in Frankfurt used cryo-electron microscopy to determine the 3D structure of complex I at high resolution. The researchers were able to show that water molecules in the protein structure play an important role for establishing proton translocation pathways.
The high-resolution structural data enabled colleagues at the University of Helsinki to conduct extensive computer simulations, which show the dynamics of the protein structure during its catalytic cycle.
Dr Janet Vonck from the Max Planck Institute of Biophysics explains: “Our study delivers new insights into how a molecular machine in biological energy conversion works." Professor Volker Zickermann from the Institute of Biochemistry II at Goethe University says: “This knowledge can contribute to a better understanding of certain mitochondrial diseases, such as loss of vision in Leber hereditary optic neuropathy."
Publication: Kristian Parey, Jonathan Lasham, Deryck J. Mills, Amina Djurabekova, Outi Haapanen, Etienne Galemou Yoga, Hao Xie, Werner Kühlbrandt, Vivek Sharma, Janet Vonck, Volker Zickermann: High-resolution structure and dynamics of mitochondrial complex I – Insights into the proton pumping mechanism. Sci Adv. 2021 Nov 12;7 (46) https://www.science.org/doi/10.1126/sciadv.abj3221
An image can be downloaded under: https://www.uni-frankfurt.de/109657054
Caption: A bit like a boot: The L-shaped structure of mitochondrial complex I at a resolution of 2.1 Ångström (0.00000021 millimetres), captured with a cryo-electron microscope. Image: Janet Vonck, MPI of Biophysics
Professor Volker Zickermann
Institute of Biochemistry II
Goethe University, Frankfurt am Main
Tel.: +49 (0)69 798-29575
Dr Janet Vonck
Max Planck Institute of Biophysics, Frankfurt am Main
Phone: +49 (0)69 6303-3004
Letter of intent signed today in Frankfurt and Israel – GU-President Schleiff: “Start of even closer cooperation”
Tel Aviv University and Goethe University want to work together even more closely in the future. A letter of intent was signed this morning in the framework of a high-profile Zoom conference, with the aim of establishing a joint research centre for religious studies and inter-religious dynamics.
FRANKFURT. A strategic partnership has already existed between the two universities since 1984, and the two cities have even been twinned since 1980. Tel Aviv University and Goethe University now want to intensify relations even further – and establish the first German-Israeli research institute. Scholars from both universities, above all in the fields of history and religious studies, have worked together regularly for many years – especially the Martin Buber Professorship at the Faculty of Protestant Theology maintains close ties with Israel. There is extensive networking between the newly founded Buber-Rosenzweig Institute for Modern and Contemporary Jewish Intellectual and Cultural History at Goethe University and the Centre for Religious and Inter-Religious Studies at Tel Aviv University in the framework of joint workshops and conferences.
The new centre will concentrate on interdisciplinary research in religious and inter-religious studies, with a focus on Judaism, Christianity and Islam. Apart from Protestant and Catholic theology, religious studies, Jewish studies and Islamic studies, other disciplines will be involved, including history, philosophy, philosophy of science and political science. Research topics are conceivable in the following areas: multicultural societies, religious conflicts, migration, fundamentalism and inter-religious dialogue. For the next 42 months, Goethe University will finance the new centre with € 50,000 per year and Tel Aviv University with an annual sum of € 20,000, especially for summer schools.
A joint directorate will be in charge of the new centre, which will bring together both senior scholars as well as early career researchers. There are also plans for joint courses from the 2022 summer semester onwards and the creation of a joint English-taught master's degree programme. Professor Christian Wiese, holder of the Martin Buber Professorship at Goethe University, Director of the Buber-Rosenzweig Institute and the research centre's initiator, sees great potential in the partnership: “In the framework of German-Israeli academic relations and the close connection between the cities of Frankfurt and Tel Aviv, we're creating something very special here – an international research hub in the field of interdisciplinary religious studies that looks at topics from a historical perspective as well as in the context of present times that challenge both societies, the German and the Israeli, each in different ways."
The contract was signed today in Tel Aviv in the presence of Dr Susanne Wasum-Rainer, German Ambassador to Israel. Due to the pandemic, the participants in Frankfurt joined the ceremony via Zoom. Professor Ariel Porat, President of Tel Aviv University, headed the meeting on the Israeli side.
Professor Enrico Schleiff, President of Goethe University
“What we are agreeing upon today is, as far as I am aware, unprecedented – at least in the humanities in Germany. It is not merely a formal cooperation between a German and an Israeli university, but rather the development of a highly visible, joint institutionalized international research centre.
The centre is cross-departmental on both sides and working in an area of study that is most relevant to the German and the Israeli society alike: the history of and the present challenges in religious diversity, difference and conflict in pluralistic societies. It will focus on questions regarding inter-religious dialogue, religious fundamentalism and conflict, but also on the rich cultural heritage and the potential inherent in religious traditions. This centre is the start of an even closer cooperation."
Dr Susanne Wasum-Rainer, German Ambassador to Israel
“Academic exchange and cooperation are not only a constitutive pillar of German-Israeli relations. They are also a contribution to strengthening research and scientific progress as a global endeavour, in science as well as in the humanities. By declaring their will to establish a joint Centre for the Study of Religious and Inter-religious Dynamics, Goethe University and Tel Aviv University are addressing one of the urgent questions of our time, the role of religious communities in a changing and conflictual world."
Professor Menachem Fisch, initiator at Tel Aviv University
“I'm delighted to be involved in the setting up of such a unique, first-of-its-kind centre for the study of the monotheistic faiths and their reciprocal development. It is a worthy initiative and another building block in academic collaboration between the two countries."
Uwe Becker, President of the German Friends
Association of Tel Aviv University
“This MOU marks a new milestone in the special relationship between the two universities and is also another bridge of understanding between Frankfurt and Tel Aviv. The new centre will for sure contribute to a better inter-religious dialogue from different angles and perspectives. I am proud that with the launch of the new German Friendship Fund we will also help students to participate in this German-Israeli experience and benefit from the activities of the German Friends Association of Tel Aviv University."
Professor Milette Shamir, TAU Vice President (International)
“Tel Aviv University has a wide collaborative network with German universities, more than with any other country in Europe. This collaboration includes hundreds of joint research projects as well as hundreds of German students who come to our campus each year. The joint centre expands this collaboration in an important new direction and reinforces our existing partnership with Goethe University, one of the leading universities in Germany. We hope that in the near future GU and TAU will expand collaboration to several other areas of common strength."
An image for download: https://www.uni-frankfurt.de/110103728
Goethe University and Tel Aviv University want to establish a joint research centre for religious studies and inter-religious dialogue. The letter of intent was signed at a large gathering, with GU president Professor Schleiff (left) and Professor Wiese participating via video link. (Photo: Uwe Dettmar)
Professor Christian Wiese
Buber-Rosenzweig Institute for Modern and Contemporary Jewish Intellectual and Cultural History
Faculty of Protestant Theology
Tel.: +49(0)69 798-33313
Processing of written and spoken language are closely aligned
When we read, our gaze moves over the text in a certain pattern. This pattern resembles – to a surprisingly high degree – the rhythm of spoken language, as a team of researchers, with the significant involvement of Goethe University, has discovered. Their research results were published on 6 December in the journal “Nature Human Behaviour".
FRANKFURT. When we read, we let our eyes wander over the text. In the process, our eye movements follow a characteristic temporal rhythm. In the framework of eye movement experiments and a meta-study with 14 different languages, an international team of researchers, with the significant involvement of Goethe University, has discovered that this temporal structure of reading is almost identical to the dominant rhythm of spoken language. It can be concluded from this, they say, that the processing of written language on the one hand and of spoken language on the other are far more similar than previously assumed. The research results have now been published in the scientific journal “Nature Human Behaviour". Other research institutions involved were the University of Vienna, the Ernst Strüngmann Institute in Frankfurt, New York University, the Max Planck Institute for Empirical Aesthetics, also in Frankfurt, and the University of Salzburg.
Languages and writing systems are central elements of human communication. For thousands of years, writing systems have enabled us not only to share information face to face but also to store it in a tangible form and make it permanently available. “Reading is one of humanity's most fascinating cultural achievements," says first author Dr Benjamin Gagl, who until recently was a research associate at the Institute of Psychology, Goethe University. “Spoken language also influences reading. Until now, however, little has been known about the common underlying mechanisms of reading and spoken language," explains Gagl, himself a psychologist.
Together with an international team led by Professor Christian Fiebach, Gagl explored these mechanisms by comparing the temporal structures of reading with those of spoken language. This revealed that the rhythmic sequences of eye movements when reading and the dominant rhythm in speech signals are almost identical. These findings shed new light on the interface between written and spoken language.
For their study, the team transferred frequency analysis methods, which are already widely used for examining phonetic speech signals, to the study of eye movements. This approach was applied in two studies at Goethe University and one at the University of Salzburg. Apart from a comparable rhythm in reading and speaking, a direct temporal coupling of reading and speech processes was detected in less experienced readers. More practiced readers, by contrast, read faster and were able to extract more information from the text between two eye movements. In addition, the authors documented in a meta-study all eye movement studies of reading published in scientific journals from 2006 to 2016 and estimated the temporal rhythm of reading for 14 languages and several writing systems. This revealed that reading rhythm is slower in logographic writing systems (such as Chinese), which can be explained by the greater effort required for the visual analysis of more complex characters.
“The results show correlations between
spoken and written language in a novel and previously unknown way," says
Christian Fiebach. “In the course of evolution, the language processing systems
of the human brain have specialised in the temporal sequences of spoken
language. On the basis of our current results, we assume that these language
systems serve as a kind of 'clock' for our eyes when reading, so that they send
the information they've read to the brain in an optimal temporal rhythm and in
this way facilitate its further analysis. This hypothesis can now be
investigated in greater depth with the methodological approach presented here."
Publication: Gagl, B., Gregorova, K., Golch, J., Hawelka, S., Sassenhagen, J., Tavano,
A., Poeppel, D. & Fiebach, C. J. (accepted). Eye movements during text
reading align with the rate of speech production. Nature Human Behaviour.
Dr Benjamin Gagl
University of Vienna
Cognitive Science Hub & Department of Linguistics
Professor Christian Fiebach
Institute of Psychology
60323 Frankfurt am Main