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The University of New Orleans, Department of Biological Sciences

Zhengchang Liu

Assistant Professor
Ph.D. (2001), University of Texas Southwestern Medical Center
Contact Info:

Phone: (504) 280-6314
Email: zliu5@uno.edu
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RESEARCH INTERESTS

Our laboratory is interested in understanding the mechanisms by which cells sense their internal and external environments by focusing on three signal transduction pathways, mitochondria-to-nucleus signaling, the TOR (target of rapamycin) signal transduction pathway, and the SPS (Ssy1-Ptr3-Ssy5) amino acid sensing pathway. We are addressing these questions by using genetic, cell biological, and biochemical approaches in the model organism Saccharomyces cerevisiae.   

Mitochondrial retrograde signaling is a pathway of communication from mitochondria to the nucleus. It involves multiple factors that sense and transmit mitochondrial signals to effect changes in nuclear gene expression; these changes lead to a reconfiguration of metabolism to accommodate cells to defects in mitochondria. Analysis of regulatory factors has provided us with a mechanistic view of regulation of retrograde signaling. We are continuing these studies by dissecting the underlying regulatory mechanisms.

Another goal of the laboratory is to understand how cells sense nutrients. Nutrients are not only central to cell growth and survival, but also able to serve as signaling molecules for signal transduction pathways. TOR signaling is a conserved, essential pathway integrating nutritional cues, especially amino acids, to cell growth and proliferative responses. The SPS amino acid sensing pathway senses external amino acids and activates the expression of amino acid transporters. We are currently studying how amino acids signal to these two pathways.

SELECTED PUBLICATIONS

  • Liu, Z., Thornton, J., Spírek, M., Butow, RA. (2008) Activation of the SPS amino acid-sensing pathway in Saccharomyces cerevisiae correlates with the phosphorylation state of a sensor component, Ptr3.  Mol. Cell. Biol. 28(2):551-63.
  • Liu, Z. and Butow, R. A. (2006) Mitochondrial retrograde signaling. Annu. Rev. Genet. 40: 159-185.
  • Giannattasio, S., Liu, Z., Thornton, J., and Butow, R. A. (2005) Retrogarde response to mitochondrial dysfunction is separable from TOR1/2 regulation of retrograde gene expression. J.  Bio. Chem. 280(52): 42528-35.
  • Liu, Z., Spirek, M., Thornton, J., and Butow, R.A. (2005) A Novel Degron-mediated Degradation of the RTG Pathway Regulator, Mks1p, by SCFGrr1. Mol. Bio. Cell. Vol. 16, 4893–4904.
  • Ferreira Junior JR, Spirek M, Liu Z, Butow R. A.  (2005) Interaction between Rtg2p and Mks1p in the regulation of the RTG pathway of Saccharomyces cerevisiae. Gene 354: 2-8.
  • Liu, Z., Sekito, T., Spirek, M., Thornton, J. and Butow, R.A. (2003).  Retrograde Signaling Is Regulated by the Dynamic Interaction between Rtg2p and Mks1p.  Molecular Cell 12: 401-411.
  • Liu, Z. and Butow, R.A. (2003).  Signaling pathways from mitochondria to the nucleus.  HANDBOOK OF CELL SIGNALING.  Edited by Bradshaw, R. and Dennis, E.  Elsevier Science.
  • Yoon, S., Liu, Z., Eyobo, Y. and Orth, K.  (2003) Yersinia effector YopJ inhibits yeast MAPK signaling pathways by an evolutionarily conserved mechanism.  J.  Bio. Chem. 278: 2131-2135.
  • Sekito, T., Liu, Z., Thornton, J., and Butow, R. A.  (2002) RTG-dependent mitochondria-to-nucleus signaling is regulated by MKS1 and is linked to the formation of the yeast prion [URE3].  Mol. Bio. Cell 13: 795-804.
  • Liu, Z., Sekito, T., Epstein, C. B., and Butow, R. A. (2001)  RTG-dependent mitochondria to nucleus signaling is negatively regulated by the seven WD-repeat protein Lst8p.  EMBO J. 20: 7209-7219.
  • Liu, Z. and Butow, R.A. (1999) A transcriptional switch in the expression of yeast tricarboxylic acid cycle genes in response to a reduction or loss of respiratory function.  Mol. Cell. Biol. 19: 6720-6728.
  • Chelstowska, A., Liu, Z., Jia, Y., Amberg D., and Butow, R. A. (1999) Signaling between mitochondria and the nucleus regulates the expression of a new D-lactate dehydrogenase activity.  Yeast 15: 1377-1391. 
  • Li, L., Liu, Z., Mercer, B., Overbeek, P., and Olson, E. N. (1997) Evidence for serum response factor-mediated regulatory networks governing SM22alpha transcription in smooth, skeletal, and cardiac muscle cells.  Dev. Biol. 187: 311-321.