Showing 801-850 of 927 Results
Assistant Professor of Radiology (Cancer Early Detection-Canary Center)
Current Research and Scholarly InterestsOur research focuses on understanding fundamental molecular mechanisms underlying cancer development. Currently, we study signaling cascades initiated by cell surface receptors which are involved in: 1) the early event of prostate cancer initiation and 2) regulation of the transition from indolent to metastatic disease. The long term goal of our laboratory is to improve the stratification of indolent from aggressive prostate cancer and aid the development of better therapeutic strategies for the advanced disease.
Additionally, we are interested in understanding molecular mechanism that govern the self-renewal activity of adult stem cells and cancer stem cells. We use molecular biology techniques, cell culture based adult stem cell assays, in vivo tissue regeneration models of cancer.
Aaron F. Straight
Professor of Biochemistry and, by courtesy, of Chemical and Systems Biology
Current Research and Scholarly InterestsWe study the biology of chromosomes. Our research is focused on understanding how chromosomal domains are specialized for unique functions in chromosome segregation, cell division and cell differentiation. We are particularly interested in the genetic and epigenetic processes that govern vertebrate centromere function, in the organization of the genome in the eukaryotic nucleus and in the roles of RNAs in the regulation of chromosome structure.
Professor of Medicine (Immunology and Rheumatology)
Current Research and Scholarly InterestsMechanisms of immune tolerance; regulatory processes in autoimmunity and transplantation and extrathymic T cell maturation.
Avram Goldstein Professor in the School of Medicine and Professor, by courtesy, of Neurology and of Psychiatry and Behavioral Sciences
Current Research and Scholarly InterestsInformation transfer at synapses mediates information processing in brain, and is impaired in many brain diseases. Thomas Südhof is interested in how synapses are formed, how presynaptic terminals release neurotransmitters at synapses, and how synapses become dysfunctional in diseases such as autism or Alzheimer's disease. To address these questions, Südhof's laboratory employs approaches ranging from biophysical studies to the electrophysiological and behavioral analyses of mutant mice.
Edith Vioni Sullivan
Professor of Psychiatry and Behavioral Sciences (Major Laboratories and Clinical Translational Neurosciences Incubator)
Current Research and Scholarly InterestsApplication of neuroimaging modalities and component process analysis of cognitive, sensory, and motor functions to identify brain structural and functional mechanisms disrupted in diseases affecting the brain: alcoholism, HIV infection, dementia, and normal aging from adolescence to senescence.
Yang Sun, MD, PhD
Associate Professor of Ophthalmology at the Stanford University Medical Center
Current Research and Scholarly InterestsWe are interested in the role of inositol phosphatases in eye development and disease, using both animal models and human disease tissue. We are a translational laboratory seeking to understand the basic function of proteins as well as developing therapeutic strategies for clinical trials.
Professor of Urology, Emeritus
Current Research and Scholarly InterestsWe focus on understanding the molecular mechanism of transcription factors that govern the transformation of normal cells to a neoplastic state. We are especially interested in nuclear hormone action and its interactions with other signaling pathways in tumor development and progression.
John B. Sunwoo
Edward C. and Amy H. Sewall Professor in the School of Medicine and Professor, by courtesy, of Dermatology
Current Research and Scholarly InterestsMy laboratory is focused on two primary areas of research: (1) the immune response to head and neck cancer and to a tumorigenic population of cells within these malignancies called cancer stem cells; (2) the developmental programs of a special lymphocyte population involved in innate immunity called natural killer (NK) cells; and (3) intra-tumor and inter-tumor heterogeneity.
Trisha Suppes, MD, PhD
Professor of Psychiatry and Behavioral Sciences (General Psychiatry and Psychology-Adult)
Current Research and Scholarly InterestsLong-term treatment strategies for bipolar disorder, treatment for bipolar II disorder, use of treatment algorithms, and treatment of major depression.
Professor of Applied Physics and, by courtesy, of Materials Science and Engineering
Current Research and Scholarly InterestsHer interests are focused on novel ground states and functional properties in condensed matter systems synthesized via atomically precise thin film deposition techniques with a recent emphasis has been on highly correlated electronic systems:
• Emergent interfacial electronic & magnetic phenomena through complex oxide heteroepitaxy
• Low dimensional electron gas systems
• Spin current generation, propagation and control in complex oxide-based ferromagnets
• Multifunctional behavior in complex oxide thin films and heterostructures
Katrin J Svensson
Assistant Professor of Pathology
Current Research and Scholarly InterestsMolecular metabolism
James H. Clark Professor in the School of Engineering and Professor of Chemical Engineering and of Bioengineering
BioUsing and Understanding Cell-Free Biology
Swartz Lab General Research Focus:
The current and projected research in the Swartz lab balances basic research in microbial metabolism, protein expression, and protein folding with a strong emphasis on compelling applications. The power and versatility of cell-free methods coupled with careful evaluation and engineering of these new systems enables a whole new range of applications and scientific investigation. Fundamental research on: the mechanisms and kinetics of ribosomal function, fundamental bioenergetics, basic mechanisms of protein folding, functional genomics, and metabolic pathway analysis is motivated by a variety of near- and medium term applications spanning medicine, energy, and environmental needs.
Swartz Lab Application Focus:
In the medical area , current research addresses the need for patient-specific vaccines to treat cancer. Particularly for lymphomas, there is a strong need to be able to make a new cancer vaccine for each patient. Current technologies are not practical for this demanding task, but cell-free approaches are rapid and inexpensive. We have already demonstrated feasibility in mouse tumor challenge studies and are now expanding the range of applications and working to improve the relevant technologies. Experience with these vaccines has also suggested a new and exciting format for making inexpensive and very potent vaccines for general use.
To address pressing needs for a new and cleaner energy source, we are working towards an organism that can efficiently capture solar energy and convert it into hydrogen. The first task is to develop an oxygen tolerant hydrogenase using cell-free technology to express libraries of mutated enzymes that can be rapidly screened for improved function. Even though these are very complex enzymes, we have produced active hydrogenases with our cell-free methods. We are now perfecting the screening methods for rapid and accurate identification of improved enzymes. After these new enzymes are identified, the project will progress toward metabolic engineering and bioreactor design research to achieve the scales and economies required.
To address environmental needs, we are developing an improved water filters using an amazing membrane protein, Aquaporin Z. It has the ability to reject all other chemicals and ions except water. We have efficiently expressed the protein into lipid bilayer vesicles and are now working to cast these membranes on porous supports to complete the development of a new and powerful water purification technology. The same lessons will be applied toward the development of a new class of biosensors that brings high sensitivity and selectivity.
Professor of Surgery (Pediatric Surgery) at the Stanford University Medical Center
Current Research and Scholarly InterestsOne of the current primary interests of the lab is to investigate the mechanisms by which hepatocellular injury and recovery is influenced and controlled by hepatocyte metabolism.
A second focus of investigation is to identify molecular markers of human disease that provide diagnostic function, serve as targets for possible therapeutic manipulation, or provide insight into mechanisms of human disease. Specific diseases of interest include newborn sepsis and Necrotizing Enterocolitis (NEC).
Daniel Sze, MD, PhD
Professor of Radiology (Interventional Radiology) at the Stanford University Medical Center
Current Research and Scholarly InterestsTransarterial administration of chemotherapeutics, radioactive microspheres, and biologics for the treatment of unresectable tumors; management of portal hypertension and complications of cirrhosis (TIPS); treatment of complications of organ transplantation; Venous and pulmonary arterial thrombolysis and reconstruction; Stent and Stent-graft treatment of peripheral vascular diseases, aneurysms, aortic dissections
Christopher N. Ta, MD
Professor of Ophthalmology at the Stanford University Medical CenterOn Partial Leave from 03/01/2020 To 02/28/2022
BioChristopher N. Ta, MD specializes in the diagnosis and medical treatment of cornea diseases. His areas of expertise are in the treatment of ocular infections, inflammation, dry eyes and ocular surface diseases. He has conducted numerous clinical trials toward the prevention and treatment of ocular infections. Dr. Ta also has extensive clinical experience in the treatment of ocular graft-versus host disease following hematopoietic stem cell transplantation.
Senior Associate Dean, Graduate Education & Postdoctoral Affairs and Professor of Developmental Biology
Current Research and Scholarly InterestsWe use genetic and cellular approaches to investigate the molecular basis of glial development and myelination in the zebrafish.
Professor of Genetics and, by courtesy, of Statistics
Current Research and Scholarly InterestsDevelop statistical and computational methods for population genomics analyses; modeling human evolutionary history; genetic association studies in admixed populations.
Jean Y. Tang MD PhD
Professor of Dermatology at the Stanford University Medical Center
Current Research and Scholarly InterestsMy research focuses on 2 main areas:
1. Skin cancer:
- New therapeutics to treat and prevent non-melanoma skin cancer, especially by targeting the Hedgehog signaling pathway for BCC tumors
- Genomic analysis of drug-resistant cancers
- Identifying risk factors for skin cancer in the Women's Health Initiative
2. Epidermolysis Bullosa: gene therapy and protein therapy to replace defective/absent Collagen 7 in children and adults with Recessive Dystrophic EB
Associate Professor of Mechanical Engineering, Senior Fellow at the Woods Institute for the Environment and Professor, by courtesy, of Radiology (Precision Health and Integrated Diagnostics)
Current Research and Scholarly InterestsThe long-term goal of Dr. Tang's research program is to harness mass transport in microfluidic systems to accelerate precision medicine and material design for a future with better health and environmental sustainability.
Current research areas include: (I) Physics of droplets in microfluidic systems, (II) Interfacial mass transport and self-assembly, and (III) Applications in food allergy, single-cell wound repair, and the bottom-up construction of synthetic cell and tissues in close collaboration with clinicians and biochemists at the Stanford School of Medicine, UCSF, and University of Michigan.
For details see https://web.stanford.edu/group/tanglab/
William Abraham Tarpeh
Assistant Professor of Chemical Engineering, by courtesy, of Civil and Environmental Engineering and Center Fellow, by courtesy, at the Woods Institute for the Environment
BioReimagining liquid waste streams as resources can lead to recovery of valuable products and more efficient, less costly approaches to reducing harmful discharges to the environment. Pollutants in effluent streams can be captured and used as valuable inputs to other processes. For example, municipal wastewater contains resources like energy, water, nutrients, and metals. The Tarpeh Lab develops and evaluates novel approaches to resource recovery from “waste” waters at several synergistic scales: molecular mechanisms of chemical transport and transformation; novel unit processes that increase resource efficiency; and systems-level assessments that identify optimization opportunities. We employ understanding of electrochemistry, separations, thermodynamics, kinetics, and reactor design to preferentially recover resources from waste. We leverage these molecular-scale insights to increase the sustainability of engineered processes in terms of energy, environmental impact, and cost.
Professor of Energy Resources Engineering
Current Research and Scholarly InterestsEnvironmental fluid mechanics, Applied and computational mathematics, Biomedical modeling.
Assistant Professor of Anesthesiology, Perioperative and Pain Medicine (Adult Pain) at the Stanford University Medical Center
Current Research and Scholarly InterestsMy overall research interest is to understand how the immune system interacts with the nervous system after injury to promote the transition from acute to chronic pain. In my clinical practice I care for patients with persistent pain that often occurs after minor trauma such as fracture or surgery. Using basic science approaches including whole system immune phenotyping with mass cytometry and genetic manipulation of peripheral and central immune cells, we seek to dissect the temporal and tissue-specific contribution of these cells to either promotion or inhibition of healing.
Mary Frances Nunez Teruel
Current Research and Scholarly InterestsThe Teruel Lab uses a combination of engineering and biological approaches including high-throughput screening of RNAi and DNA construct libraries, CRISPR libraries, targeted mass spectrometry, live-cell fluorescence microscopy, and bioinformatics to investigate the systems biology of cell differentiation and tissue renegeneration, with a particular focus on uncovering the molecular mechanisms underlying insulin resistance, diabetes, and obesity.
Assistant Professor of Radiology (Pediatric Radiology) at the Stanford University Medical Center
Current Research and Scholarly InterestsOver the past decade there has been tremendous advances in the field of Interventional Oncology with the clinical utilization of multiple new innovative locoregional therapies (i.e. chemoembolization, percutaneous ablation). Looking forward, our ability to superselectively deliver new therapies such as nanoparticles, stem cells and gene therapy will open new pathways for Interventional Radiology into the emerging field of Regenerative Medicine.
Assistant Professor of Neurosurgery at the Stanford University Medical Center
Current Research and Scholarly InterestsThe long-term goal of my research is the repair of damaged corticospinal circuitry. Therapeutic regeneration strategies will be informed by an understanding both of corticospinal motor neuron (CSMN) development and of events occurring in CSMN in the setting of spinal cord injury. MicroRNAs are small, non-coding RNAs that regulate the expression of “suites” of genes. The work in my lab seeks to identify microRNA controls over CSMN development and over the CSMN response to spinal cord injury.
Professor of Biomedical Data Science and of Statistics
Current Research and Scholarly InterestsMy research is in applied statistics and biostatistics. I specialize in computer-intensive methods for regression and classification, bootstrap, cross-validation and statistical inference, and signal and image analysis for medical diagnosis.
Professor of Genetics, of Biology and, by courtesy, of Chemistry
Current Research and Scholarly InterestsWe develop chemogenetic and optogenetic technologies for probing and manipulating protein networks, cellular RNA, and the function of mitochondria and the mammalian brain. Our technologies draw from enzyme engineering, directed evolution, chemical biology, organic synthesis, high-resolution microscopy, genetics, and computational analysis.
Professor of Medicine (Gastroenterology and Hepatology) at the Stanford University Medical Center
Current Research and Scholarly InterestsMy laboratory has been focusing on the mechanism of liver fibrogenesis and the role of hepatocyte cell death in fibrogenic injury. We have demonstrated the intricate link between hepatocyte cell death, generation of apoptotic bodies and their phagocytosis by stellate cells triggering fibrogenic activation. Key to this was the activation of the NADPH oxidase and production of reactive oxidative species inducing stellate cell transdifferentiation and collagen I transcription (Gastroenterology, 2010).
We have expanded our work focusing on the role of non-phagocytic NADPH oxidases including NOX4 in dysregulating insulin responses and precipitating stress signaling in non-alcoholic steatohepatitis. (Gastroenterology, 2015). As patients with type II diabetes mellitus develop more progressive liver disease we are now studying how advanced glycation end products (AGEs) engage RAGE signaling in the liver and NADPH oxidase-mediated redox stress.
Our ultimate goal is to translate our findings and develop novel therapeutic approaches that reverse fibrosis in NASH and improve patient outcomes.
Philip S. Tsao, PhD
Professor (Research) of Medicine (Cardiovascular Medicine)
Current Research and Scholarly InterestsOur primary interests are in the molecular underpinnings of vascular disease as well as assessing disease risk. In addition to targeted investigation of specific signaling molecules, we utilize global genomic analysis to identify gene expression networks and regulatory units. We are particularly interested in the role of microRNAs in gene expression pathways associated with disease.
George D. Smith Professor, Emeritus
Current Research and Scholarly InterestsWe study synaptic communication between brain cells with the goal of understanding neuronal computations and memory mechanisms. Main areas of focus include: presynaptic calcium channels, mechanisms of vesicular fusion and recycling. Modulation of synaptic strength through changes in postsynaptic receptors and dendritic morphology. Signaling that links synaptic activity to nuclear transcription and local protein translation. Techniques include imaging, electrophysiology, molecular biology.
The Dean and Virginia Morrison Professor of Population Studies
Current Research and Scholarly InterestsStochastic dynamics of human and natural populations; prehistoric societies; probability forecasts including sex ratios, mortality, aging and fiscal balance; life history evolution.
Minang (Mintu) Turakhia
Associate Professor of Medicine (Cardiovascular Medicine) at the Palo Alto Veterans Affairs Health Care System
Current Research and Scholarly InterestsDr. Turakhia has an active clinical research program, with funding from AHA, VA, NIH, the medical device industry, and foundations. His research program aims to improve the treatment of heart rhythm disorders, with an emphasis on atrial fibrillation, by evaluating quality and variation of care, comparative and cost-effectiveness of therapies, and risk prediction. Dr. Turakhia has extensive expertise in using large administrative and claims databases for this work. His TREAT-AF retrospective study of over 500,000 patients with newly-diagnosed AF is the largest known research cohort of AF patients. He has served as study PI or chairman of several prominent single- and multicenter trials in atrial fibrillation, investigational devices for electrophysiology procedures, digital health interventions, and sensor technologies.
His other research interests include technology assessment of new device-based therapies and the impact of changing health policy and reform on the delivery of arrhythmia care. Dr. Turakhia is a Fellow of the American Heart Association, American College of Cardiology, and Heart Rhythm Society.
Alexander Eckehart Urban
Assistant Professor of Psychiatry and Behavioral Sciences (Major Laboratories and Clinical Translational Neurosciences Incubator) and of Genetics
Current Research and Scholarly InterestsComplex behavioral and neuropsychiatric phenotypes often have a strong genetic component. This genetic component is often extremely complex and difficult to dissect. The current revolution in genome technology means that we can avail ourselves to tools that make it possible for the first time to begin understanding the complex genetic and epigenetic interactions at the basis of the human mind.
Professor of Medicine (Immunology and Rheumatology)
Current Research and Scholarly InterestsThe long-term research goal of Utz laboratory is (1) to develop a better understanding of the pathogenic mechanisms underlying systemic lupus erythematosus (SLE) and other autoimmune diseases by exploring signaling pathways that are activated during apoptosis; and (2) to better understand the complicated process of programmed cell death.
Associate Professor of Otolaryngology (Pediatric) and, by courtesy, of Pediatrics at the Lucile Salter Packard Children's Hospital
BioDr. Tulio A Valdez is a surgeon scientist born and raised in Colombia with a subspecialty interest in Pediatric Otolaryngology. He attended medical school at Universidad Javeriana in Bogota Colombia before undertaking his residency in Otolaryngology, Head and Neck Surgery in Boston. He completed his Pediatric Otolaryngology Fellowship at Texas Children’s Hospital (2007), Houston and obtained his Master’s in Clinical and Translational Research at the University of Connecticut.
Clinically, Dr. Valdez has an interest in airway surgery and swallowing disorders. He has a special interest in the management of sinus disease in cystic fibrosis. Dr. Valdez has co-authored one textbook and numerous book chapters and scientific manuscripts. Dr. Valdez continues his clinical research in these areas, particularly with a focus on aerodigestive disorders.
Scientifically, Dr. Valdez has developed various imaging methods to diagnose otitis media and cholesteatoma a middle ear condition that can lead to hearing loss. He was part of the Laser Biomedical Research Center at Massachusetts Institute of Technology. His research includes novel imaging modalities to better diagnose ear infections one of the most common pediatric problems. His research has now expanded to include better intraoperative imaging modalities in pediatric patients to improve surgical outcomes without the need for radiation exposure.
Dr. Valdez believes in the multi-disciplinary collaborations to tackle medical problems and has co-invented various medical devices and surgical simulation models.
Associate Professor of Computer Science
Current Research and Scholarly InterestsMy primary research interests lie at the intersection of algorithms, learning, applied probability, and statistics. I am particularly interested in understanding the algorithmic and information theoretic possibilities and limitations for many fundamental information extraction tasks that underly real-world machine learning and data-centric applications.
Matt van de Rijn
Sabine Kohler, MD, Professor in Pathology
Current Research and Scholarly InterestsOur research focuses on molecular analysis of human soft tissue tumors (sarcomas) with an emphasis on leiomyosarcoma and desmoid tumors. In addition we study the role of macrophages in range of malignant tumors.
Capucine van Rechem
Assistant Professor of Pathology (Pathology Research)
Current Research and Scholarly InterestsMy long-term interest lies in understanding the impact chromatin modifiers have on disease development and progression so that more optimal therapeutic opportunities can be achieved. My laboratory explores the direct molecular impact of chromatin-modifying enzymes during cell cycle progression, and characterizes the unappreciated and unconventional roles that these chromatin factors have on cytoplasmic function such as protein synthesis.
Benjamin Van Roy
Professor of Electrical Engineering, of Management Science and Engineering
BioBenjamin Van Roy is a Professor at Stanford University, where he has served on the faculty since 1998. His research focuses on understanding how an agent interacting with a poorly understood environment can learn over time to make effective decisions. He is interested in the design of efficient reinforcement learning algorithms, understanding what is possible or impossible in this domain, and applying the technology toward the benefit of society. Beyond academia, he leads a DeepMind Research team in Mountain View, and has also led research programs at Unica (acquired by IBM), Enuvis (acquired by SiRF), and Morgan Stanley.
He is a Fellow of INFORMS and IEEE and has served on the editorial boards of Machine Learning, Mathematics of Operations Research, for which he co-edits the Learning Theory Area, Operations Research, for which he edited the Financial Engineering Area, and the INFORMS Journal on Optimization.
He received the SB in Computer Science and Engineering and the SM and PhD in Electrical Engineering and Computer Science, all from MIT. He has been a recipient of the MIT George C. Newton Undergraduate Laboratory Project Award, the MIT Morris J. Levin Memorial Master's Thesis Award, the MIT George M. Sprowls Doctoral Dissertation Award, the National Science Foundation CAREER Award, the Stanford Tau Beta Pi Award for Excellence in Undergraduate Teaching, and the Management Science and Engineering Department's Graduate Teaching Award. He has held visiting positions as the Wolfgang and Helga Gaul Visiting Professor at the University of Karlsruhe, the Chin Sophonpanich Foundation Professor and the InTouch Professor at Chulalongkorn University, a Visiting Professor at the National University of Singapore, and a Visiting Professor at the Chinese University of Hong Kong, Shenzhen.
Shreyas Vasanawala, MD/PhD
Professor of Radiology (Pediatric Radiology)
Current Research and Scholarly InterestsOur group is focused on developing new fast and quantitative MRI techniques.
Assistant Professor of Neurosurgery and, by courtesy, of Orthopaedic Surgery at the Stanford University Medical Center
Current Research and Scholarly InterestsThe focus of my laboratory is to utilize precision medicine techniques to improve the diagnosis and treatment of neurologic conditions. From traumatic brain injury to spinal scoliosis, the ability to capture detailed data regarding clinical symptoms and treatment outcomes has empowered us to do better for patients. Utilize data to do better for patients, that’s what we do.
Stanford Neurosurgical Ai and Machine Learning Lab
Assistant Professor of Comparative Medicine at the Stanford University Medical Center
BioDr. José G. Vilches-Moure, DVM, PhD, Assistant Professor, received his DVM degree from Purdue University in Indiana in 2007. He completed his residency training in Anatomic Pathology (with emphasis in pathology of laboratory animal species) and his PhD in Comparative Pathology at the University of California-Davis. He joined Stanford in 2015, and is the Director of the Animal Histology Services (AHS). Dr. Vilches-Moure is a diplomate of the American College of Veterinary Pathologists, and his collaborative research interests include cardiac development and pathology, developmental pathology, and refinement of animal models in which to study early cancer detection techniques. His teaching interests include comparative anatomy/histology, general pathology, comparative pathology, and pathology of laboratory animal species.
Professor of Developmental Biology and of Genetics
Current Research and Scholarly InterestsMechanisms underlying homologous chromosome pairing, DNA recombination and chromosome remodeling during meiosis, using the nematode Caenorhabditis elegans as an experimental system. High-resolution 3-D imaging of dynamic reorganization of chromosome architecture. Role of protease inhibitors in regulating sperm activation.
Hannes Vogel MD
Professor of Pathology and of Pediatrics (Pediatric Genetics) and, by courtesy, of Neurosurgery and of Comparative Medicine at the Stanford University Medical Center
Current Research and Scholarly InterestsMy research interests include nerve and muscle pathology, mitochondrial diseases, pediatric neurooncology, and transgenic mouse pathology.
Associate Professor of Genetics and, by courtesy, of Ophthalmology
Current Research and Scholarly InterestsThe Vollrath lab works to uncover molecular mechanisms relevant to the health and pathology of the outer retina. We study the retinal pigment epithelium (RPE), a cell monolayer adjacent to photoreceptors that performs a variety of tasks crucial for retinal homeostasis. Specific areas of interest include the circadian regulation of RPE phagocytosis of photoreceptor outer segment tips, and how RPE metabolic dysfunction contributes to retinal degenerative diseases.
Jensen Huang Professor of Global Leadership and Professor, by courtesy, of Applied Physics
Current Research and Scholarly Interestsphotonics, quantum technologies, quantum optics, inverse design
Lucie Stern Professor in the Social Sciences
Current Research and Scholarly InterestsCognitive neuroscience of memory and cognitive/executive control in young and older adults. Research interests include encoding and retrieval mechanisms; interactions between declarative, nondeclarative, and working memory; forms of cognitive control; neurocognitive aging; functional organization of prefrontal cortex, parietal cortex, and the medial temporal lobe; assessed by functional MRI, scalp and intracranial EEG, and transcranial magnetic stimulation.
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.
Professor of Biology
Current Research and Scholarly InterestsOur current focus is on maize anther development to understand how cell fate is specified. We discovered that hypoxia triggers specification of the archesporial (pre-meiotic) cells, and that these cells secrete a small protein MAC1 that patterns the adjacent soma to differentiate as endothecial and secondary parietal cell types. We also discovered a novel class of small RNA: 21-nt and 24-nt phasiRNAs that are exceptionally abundant in anthers and exhibit strict spatiotemporal dynamics.