School of Medicine

Wayne State University School of Medicine

Xuequn Chen, Ph.D.
Assistant Professot
5215 Scott Hall
313-577-6058
Areas
Cellular and Molecular Physiology
Laboratory Web Site
Biography

The secretory pathway is responsible for the processing and trafficking of a wide variety of protein cargoes including hormones, enzymes, receptors, ion channels and transporters. The balance between synthesis, folding, transport, degradation and secretion of these proteins in the secretory pathway is vital for cell and organism survival. The disruption of this homeostasis can lead to numerous human diseases such as cystic fibrosis, Alzheimer’s disease, diabetes and pancreatitis. In spite of the importance of the secretory pathway and the extensive research in past decades, there are many questions remained unsolved including the detailed molecular mechanisms for cargo sorting and maintenance of the identities of different membrane compartments, and most importantly the regulation of the molecular machinery in the secretory pathway under different physiological and pathological conditions. Our current incomplete understanding of these fundamental mechanisms precludes the efficient treatment of the above human diseases. The long term research goal of my lab is, using systems physiology approaches and specialized secretory tissues as models, to understand the molecular machinery of the secretory pathway governing the intracellular protein homeostasis and trafficking, and more importantly the regulation of the machinery under different metabolic, physiological and pathological conditions. My research has been focused on cellular physiology and functional proteomics studies of protein homeostasis and membrane trafficking in mammalian secretory pathway such as the endoplasmic reticulum homeostasis in normal and diseased states, molecular architecture and regulated exocytosis of secretory granules and cell cycle regulated Golgi biogenesis. The systems physiology approaches used in our research are the combination of the quantitative mass spectrometry technology, cellular and integrative physiology, biochemistry and bioinformatics approaches. 

Publications
  • Chen, X., Li, C., Izumi T., ErnstS.A., Andrews, P. C. and Williams, J.A.  Rab27b localizes to ZG membrane and regulates acinar secretion, Biochem. Biophys. Res. Commun.  323:1156-1161, 2004
  • Chen, X., Walker, A. K., Strahler, J. R., Simon, E. S., Volk, S. L., Nelson, B. B., Hurley, M. C., Ernst, S.A., Williams, J.A., and Andrews, P. C.  Organellar proteomics: analysis of pancreatic zymogen granule membranes.  Molecular & Cellular Proteomics  5(2): 306-12, 2006 
  • Chen, X., and Andrews, P. C. Purification and Proteomics analysis of pancreatic zymogen granule membrane. In Volume: Organellar Proteomics Methods in Molecular Biology  432:275-87, 2008
  • Evans, E., Zhang, W., Jerdeva, G., Chen, C.Y., Chen, X., Hamm-Alvarez, S.F. and Okamoto, C.T.  Direct interaction between Rab3D and the polymeric immunoglobulin receptor may regulate its trafficking through regulated secretory vesicles in lacrimal gland acinar cells. Am. J. Physiol.  294(3):C662-74, 2008 (I generated the recombinant adenoviruses of wild type and mutant Rab3D)  
  • Sabbatini, E., Chen, X., Ernst, S. A. and Williams, J. A.  Rap1 activation plays a regulatory role in pancreatic amylase secretion. J. Biol. Chem.  283:23884-94, 2008 (I contributed to the experimental design, assay development and subcellular localization study of Rap1)
  • Chen, X., Ulintz, P., Simon, E., Williams, J. A., and Andrews, P. C.  Global topology analysis of pancreatic zymogen granule membranes.  Molecular & Cellular Proteomics.   7(12): 23232336, 2008
  • Chen, X., and Andrews, P. C. Quantitative proteomics analysis of pancreatic zymogen granule membrane. In Volume: Membrane Proteomics Methods in Molecular Biology 527:327-38, 2009
  • Williams, J. A., Chen, X and Sabbatini, M. E.  Small G Proteins as Key Regulators of Pancreatic Digestive Enzyme Secretion. Am. J. Physiol. Endocrinol Metab. 296(3): E405-14, 2009  Review 
  • Chen, X., Sans, D., Strahler, J. R., Michailidis, G., Ernst, S. A., Andrews, P. C. and Williams, J.A.  Quantitative proteomics analysis of Rough Endoplasmic Reticulum from normal and acute pancreatitis rat pancreas.  Journal of Proteome Research   9(2):885-96, 2010
  • Chen, X., Simon, E., Xiang, Y., Kachman, M., Andrews, P. C. and Wang, Y.  Quantitative proteomics analysis of cell cycle regulated Golgi disassembly and reassembly.  J. Biol. Chem.  285(10):7197-207, 2010 
  • Chen, X., Karnovsky, A., Sans, D., Andrews, P. C. and Williams, J.A. Molecular Architecture of the Endoplasmic Reticulum: insights from proteomics studies. Special Issue on Subcellular Proteomics, Proteomics  Invited review  10:4040-4052, 2010.
  • Chen, X., Simon, E., Xiang, Y., Kachman, M., Andrews, P. C. and Wang, Y.  Quantitative proteomics analysis of cell cycle regulated Golgi disassembly and reassembly.  J. Biol. Chem.  285(10):7197-207, 2010.
  • Chen, X., Sans, D., Strahler, J. R., Michailidis, G., Ernst, S. A., Andrews, P. C. and Williams, J.A.  Quantitative organellar proteomics analysis of Rough Endoplasmic Reticulum from normal and acute pancreatitis rat pancreas.  Journal of Proteome Research   9(2):885-96, 2010.
Awards & Honors
  • The Distinguished Thesis Award, Nankai University 1995
  • Shen Shouchun Experimental Physics Award, Nankai University 1995 
  • Caroline tum Suden / Frances A. Hellebrandt Professional Opportunity Award for meritorious research in Physiology (2001)
  • Abbott Laboratories Graduate Student Award for outstanding research accomplishments in gastrointestinal (2001)
  • The Rackham Graduate School Predoctoral Fellowship ( 2002)
  • Best Poster Award, Gordon Conference on Salivary Glands and Exocrine Secretion, Ventura CA (2005) 
  • Travel Award for Junior Faculty, American Pancreas Association, Chicago IL (2007) 
Post Graduate Training
  •  2003-2007 Postdoctoral fellow-National Resources for Proteomics & Pathways, University of Michigan, Ann Arbor, MI
Education
  •  Nankai UniversityTianjinChinaB.S. in Biophysics, 1992
  • Nankai UniversityTianjinChinaM.S. in Biophysics, 1995
  • University of MichiganAnn ArborMIPh.D. in Physiology 2003