SLAC National Accelerator Laboratory
Showing 1,601-1,700 of 1,733 Results
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Soichi Wakatsuki
Professor of Photon Science and of Structural Biology
Current Research and Scholarly InterestsUbiquitin signaling: structure, function, and therapeutics
Ubiquitin is a small protein modifier that is ubiquitously produced in the cells and takes part in the regulation of a wide range of cellular activities such as gene transcription and protein turnover. The key to the diversity of the ubiquitin roles in cells is that it is capable of interacting with other cellular proteins either as a single molecule or as different types of chains. Ubiquitin chains are produced through polymerization of ubiquitin molecules via any of their seven internal lysine residues or the N-terminal methionine residue. Covalent interaction of ubiquitin with other proteins is known as ubiquitination which is carried out through an enzymatic cascade composed of the ubiquitin-activating (E1), ubiquitin-conjugating (E2), and ubiquitin ligase (E3) enzymes. The ubiquitin signals are decoded by the ubiquitin-binding domains (UBDs). These domains often specifically recognize and non-covalently bind to the different ubiquitin species, resulting in distinct signaling outcomes.
We apply a combination of the structural (including protein crystallography, small angle x-ray scattering, cryo-electron microscopy (Cryo-EM) etc.), biocomputational and biochemical techniques to study the ubiquitylation and deubiquitination processes, and recognition of the ubiquitin chains by the proteins harboring ubiquitin-binding domains. Current research interests including SARS-COV2 proteases and their interactions with polyubiquitin chains and ubiquitin pathways in host cell responses, with an ultimate goal of providing strategies for effective therapeutics with reduced levels of side effects.
Protein self-assembly processes and applications.
The Surface layers (S-layers) are crystalline protein coats surrounding microbial cells. S-layer proteins (SLPs) regulate their extracellular, self-assembly by crystallizing when exposed to an environmental trigger. We have demonstrated that the Caulobacter crescentus SLP readily crystallizes into sheets both in vivo and in vitro via a calcium-triggered multistep assembly pathway. Observing crystallization using a time course of Cryo-EM imaging has revealed a crystalline intermediate wherein N-terminal nucleation domains exhibit motional dynamics with respect to rigid lattice-forming crystallization domains. Rate enhancement of protein crystallization by a discrete nucleation domain may enable engineering of kinetically controllable self-assembling 2D macromolecular nanomaterials. In particular, this is inspiring designing robust novel platform for nano-scale protein scaffolds for structure-based drug design and nano-bioreactor design for the carbon-cycling enzyme pathway enzymes. Current research focuses on development of nano-scaffolds for high throughput in vitro assays and structure determination of small and flexible proteins and their interaction partners using Cryo-EM, and applying them to cancer and anti-viral therapeutics.
Multiscale imaging and technology developments.
Multimodal, multiscale imaging modalities will be developed and integrated to understand how molecular level events of key enzymes and protein network are connected to cellular and multi-cellular functions through intra-cellular organization and interactions of the key machineries in the cell. Larger scale organization of these proteins will be studied by solution X-ray scattering and Cryo-EM. Their spatio-temporal arrangements in the cell organelles, membranes, and cytosol will be further studied by X-ray fluorescence imaging and correlated with cryoEM and super-resolution optical microscopy. We apply these multiscale integrative imaging approaches to biomedical, and environmental and bioenergy research questions with Stanford, DOE national labs, and other domestic and international collaborators. -
Gang Wan
Postdoctoral Research Fellow, Photon Science, SLAC
BioUniversity of Science and Technology of China
Shanghai Institute of Ceramics
Lab graduate student, Argonne National Laboratory (2016-2018)
Stanford Advisors:
Michael Toney Postdoctoral Research Mentor
Piero Pianetta Postdoctoral Faculty Sponsor -
William Weis
William M. Hume Professor in the School of Medicine, Professor of Structural Biology, of Molecular and Cellular Physiology and of Photon Science
Current Research and Scholarly InterestsOur laboratory studies molecular interactions that underlie the establishment and maintenance of cell and tissue structure. Our specific areas of interest are the architecture and dynamics of intercellular adhesion junctions, the molecular basis of cell polarity, and the Wnt signaling pathway. We also have a long-standing interest in carbohydrate-based cellular recognition and adhesion.
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Thomas Wolf
Staff Scientist, SLAC National Accelerator Laboratory
BioThomas Wolf is a Staff Scientist at SLAC National Accelerator Laboratory. He received his master's degree in Chemistry from University of Karlsruhe, Germany, in 2009. In 2012, he received his PhD degree in Physical Chemistry at Karlsruhe Institute of Technology, Germany. After a postdoctoral stay at Karlsruhe Institute of Technology, he joined the Gühr research group at SLAC National Accelerator Laboratory in 2013. He has been working in his current role as PI of the Excited States in Isolated Molecules group within the Stanford PULSE Institute since 2016.
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Jun Xiao
Postdoctoral Research Fellow, Photon Science, SLAC
BioDr. Jun Xiao received a Ph.D. degree in Applied Physics from UC Berkeley (2018) and a B.S. degree in Physics from Nanjing University (2012).
Jun’s research has centered on the exploration of the emerging properties of two-dimensional materials through the application of a wide range of optical spectroscopy, scanning probe microscopy and electrical measurements. More specifically, he conducted experimental investigation in how crystal symmetry and symmetry breaking substantially influence on optoelectronic properties, polar structures and phase transitions in two-dimensional systems. Along this line, Jun is also interested in visualizing the ultrafast dynamics and driving nonequilibrium phase transition in quantum materials.
Dr. Jun Xiao has published over 10 high-impact journal papers including publications in Science, Nature, Nature Nanotechnology, Physical Review Letters and Nature Communications.
