Photo of Faculty MemberOur lab is interested in developing new tools for mapping 3D organization of biomolecules and probing biological processes in the tissue and organism.

Complex biological systems are delicate machines consist of building blocks (such as proteins, nucleic acids, lipids, and carbohydrates) that are precisely organized in the nanoscale. This presents a fundamental challenge for humanity to understand the biology and/or pathology underlying these complex systems. To gain the insight into physiological/pathological functions, one might need to map a large diversity of nanoscale building blocks, over a wide spatial scale. To tackle this challenge, we are developing a set of novel technologies that enable large scale visualization of biological samples with nanoscale precision, by physically expanding the sample rather than magnifying the light from the sample via lenses. This principle is called expansion microscopy (ExM). By combining various material engineering and chemical approaches, we are advancing ExM-based tools that may elucidate biological insights into the brain and other complex systems, such as cancer and infectious diseases.


 

Education

B.S. Chemistry, 2009, Sun Yat-sen University
PhD Chemistry, 2014, University of Alberta

Postdoctoral Training

2017, Bioengineering/Pathology, Massachusetts Institute of Technology



 

Zhao Biophotonics Laboratory
Carnegie Mellon University
202A Mellon Institute
Department of Biological Sciences
4400 Fifth Ave
Pittsburgh, PA 15213

Phone: (412) 268-8236
Fax: (412) 268-1809

E-mail: Link

Website: Link


 

Photo of Faculty MemberOur laboratory is interested in the fundamental question of how the cell controls the morphology and structure of its membranes. To this end, we are particularly interested in understanding endosomal sorting and the molecular mechanisms of endosomal membrane remodeling. Remodeling is performed by members of several protein families, including the SNX-BAR proteins and the dynamin-related proteins (DRPs). SNX-BAR and DRP mutations are both associated with health challenges, including neurodegenerative diseases such as Alzheimer’s and Parkinson’s.

We use structural and biophysical approaches, supplemented with in vivo and high throughput genetic studies in the model organism S. cerevisiae. Recently, we used cryo-electron microscopy and X-ray crystallography, combined with live cell imaging and functional cell biological approaches, to characterize a retromer-dependent SNX-BAR involved in retrograde trafficking from the endosome as well as a DRP involved in endosomal membrane remodeling. In both cases, the structures we generated provided novel insights into the regulation of their function by self-assembly.

Our current work aims to understand how various SNX-BAR complexes are regulated and how they engage with their respective cargoes and binding partners, including members of the DRP family.

 


 

Education



Postdoctoral Training




 

Department of Cell Biology
University of Pittsburgh
3500 Terrace Street
Pittsburgh, PA 15261




Cell nucleus, lamins, nuclear lamina


 

We study mechanical and rheological properties of the nucleus. In deciphering the structural and mechanical elements of the cell's nucleus we hope to determine roles of epigenetic regulation, stem cell differentiation, aging pathologies and cancer metastases. Mechanical regulation of cell and tissue function is poorly understood but is a fascinating area of study. Our research focuses on molecular, organelle, cellular and multicellular length scales over time, and we use a combination of spectroscopic, imaging, image informatics, biophysics and computational approaches.

 

 

 

 


Education

PhD 2004, University of Pennsylvania

Postdoctoral Training

Johns Hopkins University School of Medicine, Department of Cell Biology


 

Carnegie Mellon University
Department of Chemical Engineering
Doherty Hall 2100C
5000 Forbes Ave. 
Pittsburgh, PA 15213

Phone: (412) 268-9609 
Fax: (412) 268-7139

E-mail: krisdahl@cmu.edu 

Visit website 


 

 

 

We study how macromolecules interact and condense into liquid droplets in cells to promote cellular functions. In our work, we combine optogenetic manipulation, live cell imaging, in vitro reconstitution, biophysical quantification with mathematic modeling. Our current focus is to reveal the mechanism of liquid condensation driven by protein-protein and protein-RNA interactions on telomeres, protective DNA repeats on chromosome ends. We aim to understand how such condensation contributes to telomere elongation, the process of actively adding new telomere DNA that all cancer cells need to undertake to avoid cell death triggered by short telomeres. 

 

  

 

 


 

Education

PhD 2011, McGill University



Postdoctoral Training

2015-2018 University of Pennsylvania
2015-2015 Princeton University
2011-2015 Dartmouth College




 

Department of Biological Sciences
Carnegie Mellon University
601 Mellon Institute
4400 Fifth Avenue
Pittsburgh, PA 15213

Phone: (412) 268-3180

E-mail: huaiyinz@andrew.cmu.edu

Website


NMR of ion channels & low-affinity drug action


 

Research efforts in Dr. Xu's group are directed to three projects: (1); membrane protein structures and dynamics by NMR; (2); low-affinity drug interaction with membrane proteins, and (3); gene and stem cell therapy for brain protection and revitalization after cardiac arrest and resuscitation. The current focuses are as follows. For Project 1, NMR is used to determine the transmembrane domain structures of the human glycine receptor, which is the primary inhibitory receptors in the spinal cord and responsible for a wide range of diseases. The long-term goal is to provide the structural basis for novel design of drugs that are disease specific and devoid of side effects. For Project 2, experimental and theoretical approaches are combined to study how low affinity neurological agents, such as alcohol and general anesthetics, exert their effects on the central nervous system at the molecular level. The goal is to shed new lights on the great unsolved mystery of modern medicine: the molecular mechanisms of general anesthesia. For Project 3, new gene therapy strategies are being developed to target a special event called reperfusion injury after cardiac arrest and resuscitation. Recently, Dr. Xu's group combines gene therapy with stem cell therapy using a non-controversial source of stem cells, in an effort to stop and reverse the neuronal loss and to rebuild neuronal circuitry after reperfusion from prolonged cardiac arrest or stroke.

Students in Dr. Xu's laboratory have the opportunity to learn a variety of modern techniques, including expression and purification of membrane proteins, immunohistochemistry, high-resolution nuclear magnetic resonance imaging and spectroscopy, imaging reconstruction, 3-D protein structure calculation, and molecular dynamics simulations.

 

 


 
Education

PhD 1990, State University of New York

Postdoctoral Training

University of California at San Francisco

 

 


Department of Anesthesiology
University of Pittsburgh
Biomedical Science Tower 3, Room 2048
3501 Fifth Avenue
Pittsburgh, PA 15260 

Phone: (412) 648-9922 
Fax: (412) 648-8998

E-mail: xuy@anes.upmc.edu  

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