General

Pingyong Xu
Professor
Institute of Biophysics,Chinese Academy of Sciences
Email: pyxu@ibp.ac.cn
Telephone: 010-64888808
Address: 15# Datun Road,Chaoyang District,Beijing,China 
Postcode: 100101

Research Areas

    Our studies focus on two aspects: one combines spectroscopy, biophysical microscopy techniques, and protein design and engineering for the development of novel optical imaging tools, especially photocontrollable fluorescent proteins and functional chemical dyes. In addition, our research uses the probes we develop in SR techniques to study important biological processes such as autophagosome formation.

    Using fluorescence microscopy, information about the spatial organization of specific target proteins can be accurately provided at the molecular level by labeling proteins with fluorescent proteins. However, conventional optical microscopy is limited by diffraction to imaging on a coarser scale (~250 nm) by two orders of magnitude. Recently, several SR imaging techniques, such as single molecule localization-based microscopy (PALM/FPALM/STORM) and structured illumination-based techniques such as nonlinear structured illumination microscopy (NL-SIM), were developed for the study of cellular ultrastructure at diffraction-unlimited resolutions. However, many efforts are still needed to improve the spatial and temporal resolutions and labeling technology, especially in living cells. One of the major limits is the absence of appropriate fluorescent probes with specific photochemical properties. Different SR techniques use different fluorescent probes with optimized properties. Live-cell SR imaging is also very challenging because it requires fluorescent proteins to be very stable and bright and have a high contrast ratio. We mainly focus on developing novel fluorescent probes, especially fluorescent proteins that show priority to dyes in living cells, for diffraction-unlimited optical microscopy. We hope to further improve the spatial-temporal resolution using multiple fluorescent labels with higher photon numbers and contrast ratios.

    Although many current SR techniques have been successfully demonstrated to image cellular dynamics, applications have been rather limited and appear challenging. Live-cell STED/reversible saturable optical fluorescence transition (RESOLFT) and SIM/nonlinear SIM require sophisticated and expensive optical setups and professional expertise for accurate optical alignment. Live-cell PALM/STORM uses a less complicated setup; however, a sCMOS camera, whose pixel-dependent noise should be pre-characterized and calibrated before use, is required for extremely high acquisition speeds over tens of thousands of frames. Recently, wide-field based SR microscopies have been developed to improve temporal resolution using much fewer time-lapse images (hundreds to thousands) than PALM/STORM. One of them, a Bayesian analysis of blinking and bleaching (3B), offers enormous potential to resolve ultrastructure and fast cellular dynamics beyond the diffraction limit in living cells. Despite the potential, the 3B analysis is impractical when imaging the nanoscale dynamics of large fields of view in live cells over long time periods, as the calculation is extremely time-consuming and/or consumes large amounts of web resources. Another major problem for 3B imaging is the artificial thinning and thickening of structures both in simulated images and experimental data. Our goal is to develop simple but useful SR techniques with high spatial-temporal resolution. We are developing novel algorithms and imaging techniques based on a simple TIRFM system to make them useful SR imaging tools in common labs for both fixed and living cells.

    At present, the research on localization and related functions of proteins using super-resolution imaging techniques in the field of neuroscience is still at an early stage. Probes and methods for characterizing neuronal activity are yet to be further developed. Our group will take advantage of our expertise in fluorescent protein engineering and methods to develop novel probes and methods for characterizing neuronal activity and to investigate the localization and function usingsuper-resolution imaging techniques in neurons.


Education

1992 - 1996 Central China Normal University, B.S. in Chemical Education, Wuhan, China
1996 - 2000 Central China Normal University, M.S. in Organic Chemistry, Wuhan, China
2000 - 2004 Huazhong University of Science and Technology, Ph.D. in Engineering of Biomedicine, Wuhan, China

Experience

   
Work Experience

2004 - 2006 Postdoctoral Fellow, Assistant Professor, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
2006 - 2010 Associate Professor, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
2010 -   Professor, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China

Teaching Experience

Molecular biology

Experiment of Molecular biology and biochemistry 

Honors & Distinctions

2015   China optical important achievement award,Chines Laser Press

2008  The State Natural Science Award (the second class), P.R.CHINA 

2009  Lu Jiaxi Young Talent Award from Chinese Academy of Sciences 

2011   Youth association for the advancement of innovation fund of Chinese academy of science

Publications

(1) Optical Nanoscopy and Novel Microscopy Techniques(chapter: Fluorescent proteins for optical microscopy,pp 111-134) ,CRC Press,2014 
(2) Molecular Mechanisms of Neurotransmitter Release ,Humana Press ,2008

Papers

(1) Hessian single-molecule localization microscopy using sCMOS camera, Biophysics Reports, 2018, co-corresponding author

(2) Etoposide-induced protein 2.4 functions as a regulator of the calcium ATPase and protects pancreatic β cell survival, Journal of Biological Chemistry, 2018, co-corresponding author
(3) Temporal Transcriptomic and Proteomic Landscapes of Deteriorating Pancreatic Islets in Type 2 Diabetic Rats, Diabetes, 2017, eighth author 
(4) Live-cell single molecule-guided Bayesian localization super-resolution microscopy, Cell Research, 2017,co-corresponding author
(5) A photoactivatable Znsalen complex for superresolution imaging of mitochondria in living cells, Chem. Commun., 2016, sixth author 
(6) Extending the spatiotemporal resolution of super-resolution microscopies using photomodulatable fluorescent proteins, Journal of Innovative Optical Health Sciences, 2016, co-corresponding author
(7) Highly photostable, reversibly photoswitchable fluorescent protein with high contrast ratio for live-cell superresolution microscopy, Proc Natl Acad Sci U S A, 2016, co-corresponding author
(8) HID-1 is required for homotypic fusion of immature secretory granules during maturation, eLife, 2016, co-corresponding author
(9) Extended-resolution structured illumination imaging of endocytic and cytoskeletal dynamics, Science, 2015, tenth author 
(10) Development of a Reversibly Switchable Fluorescent Protein for Super-Resolution Optical, ACS Nano, 2015, co-corresponding author
(11) Bayesian localization microscopy based on intensity distribution of fluorophores, Protein Cell, 2015, co-corresponding author
(12) beta-Lactonization of fluorinate porphyrin enhances LDL binding affinity, cellular uptake with selective intracellular localization, CHEMICAL SCIENCE, 2014, co-corresponding author
(13) The specific and rapid labeling of cell surface proteins with recombinant FKBP-fused fluorescent proteins, Protein Cell, 2014, co-corresponding author
(14) A sensitive and quantitative autolysosome probe for detecting autophagic activity in live and prestained fixed cells, Autophagy, 2013, co-corresponding author
(15) Light-induced protein translocation by genetically encoded unnatural amino acid in Caenorhabditis elegans, Protein Cell, 2013, co-corresponding author
(16) An aromatic amino acid in the coiled-coil 1 domain plays a crucial role in the auto-inhibitory mechanism of STIM1, Biochemical Journal, 2013, co-corresponding author
(17) C13C4.5/Spinster, an evolutionarily conserved protein that regulates fertility in C-elegans through a lysosome-mediated lipid metabolism process, Protein Cell, 2013, co-corresponding author
(18) Rational Design of ZnSalen as a Single and Two Photon Activatable Fluorophore in Living Cells, Chemical Science, 2012, co-corresponding author
(19) Rational design of true monomeric and bright photoactivatable fluorescent proteins, Nature Methods, 2012, co-corresponding author
(20) A novel fluorescent protein pair for dual-color two-photon laser scanning microscopy., Progress in Biochemistry and Biophysics., 2012, co-corresponding author
(21) A new series of reversibly switchable fluorescent proteins with beneficial properties for various applications, Proc Natl Acad Sci U S A, 2012, co-corresponding author
(22) HID-1 is a peripheral membrane protein primarily associated with the medial- and trans- Golgi apparatus, Protein Cell, 2011, co-corresponding author
(23) HID-1 is a novel player in the regulation of neuropeptide sorting, Biochem J., 2011, co-corresponding author
(24) Luminescent zinc salen complexes as single and two-photon fluorescence subcellular imaging probes, Chem Commun (Camb), 2011, co-corresponding author
(25) Mechanism of different spatial distributions of Caenorhabditis elegans and human STIM1 at resting state, Cell Calcium, 2009, co-corresponding author
(26) Functional stoichiometry of the unitary calcium-release-activated calcium channel, Proc Natl Acad Sci U S A, 2008, first author  
(27) Overlapping functions of different dynamin isoforms in clathrin-dependent and -independent endocytosis in pancreatic beta cells, Biochem Biophys Res Commun, 2008, co-corresponding author
(28) A pre-docking role for microtubules in insulin-stimulated glucose transporter 4 translocation, FEBS J., 2008, co-corresponding author
(29) Mapping the interacting domains of STIM1 and Orai1 in Ca2+ release-activated Ca2+ channel activation, J Biol Chem., 2007, first author  
(30) Interaction of Munc18 and Syntaxin in the regulation of insulin secretion, Biochem Biophys Res Commun., 2007, co-corresponding author
(31) Role of H(abc) domain in membrane trafficking and targeting of syntaxin 1A, Biochem Biophys Res Commun., 2007, co-corresponding author
(32) Dissecting Multiple Steps of GLUT4 Trafficking and Identifying the Sites of Insulin Action,  Cell Metab. , 2007, co-corresponding author
(33) Aggregation of STIM1 underneath the plasma membrane induces clustering of Orai1, Biochem Biophys Res Commun., 2006,first author  
(34) Munc13-1 is required for the sustained release of insulin from pancreatic beta cells, Cell Metab., 2006, third author 
(35) Domain requirement for the membrane trafficking and targeting of syntaxin 1A, J Biol Chem., 2006, co-corresponding author
(36) Direct interaction with syntaxin 1A defines the intracellular localization of Munc18a, Progress in Biochemistry and Biophysics, 2005, first author  
(37)  A new pair for inter- and intra-molecular FRET measurement, Biochem Biophys Res Commun., 2005, first author  

Patents
A Bayesian Microscopic Imaging Method,China,201610282305.5


Conferences

(1) 1st China Forum on Biosensors, Biochips and Nanobiotechnology,Photo-controllable Fluorescent proteins for super-resolution microscopy in living cells,2017-10

(2) Pacifichem 2015,Developing photoactivatable fluorescent proteins for superresolution imaging,2015-12

(3) The 2nd East-Asia Microscopy Conference (EAMC2),Live cell superresolution imaging with unique photoactivatable fluorescent proteins,2015-11

(4) International Union of Pure and Applied Biophysics(IUPAB), Reversibly switchable fluorescent proteins for single molecule localization-based super-resolution imaging, 2014-08

(5) The 58th Annual Meeting of the Biophysical Society, Developing Photoactivitable Fluorescent Proteins for Diffraction-limited and Superresolution Imaging, co-chair for section"Imaging & Optical Microscopy –Technology" ,2014-02

(6) The 17th International Biophysics Congress (IUPAB) , Rational design of true monomeric and bright photoactivatable and photoconvertible fluorescent proteins, 2011-11
(7) The 16th International Symposium on Chromaffin Cell Biology (ISCC) , A new series of reversibly switchable fluorescent proteins (RSFPs) with beneficial properties for various applications, 2011-07

Collaboration

    Our research in super-resolution microscopy imaging is widely approved over the world, so many international and domestic famous experts collaborate with with us. 
    HHMI, Eric Betzig (the winner of 2014 Nobel Prize in chemistry, expert of ultra high resolution imaging). We get breakthroughs in nonlinear structure light (NL - SIM) with a new fluorescent protein Skylan-NS the paper has been published in Science and PNAS; 
    NIH, Jennifer Lippincott - Schward (Academician of National Academy of Sciences, Founder of PALM imaging). We get breakthroughs in SIMBA imaging methods, and the paper has been published in Cell Research
    Peking University.