Biochemistry

Shuqun Zhang

Professor of Biochemistry

E-mail:zhangsh@missouri.edu

Office: 371G Bond Life Sciences Center

Mail: Christopher S. Bond Life Sciences Center
371G Bond Life Sciences Center
University of Missouri
Columbia, MO 65211

Phone: 573-882-5837

Fax: 573-884-9676

Lab: 573-884-7191

Educational background

Notable honors and service

• CAREER Award, National Science Foundation (2002)

Research description

Research description: Protein phosphorylation and dephosphorylation play important signaling roles in plant response to environmental stimuli. Extensive recent research in yeast and animals demonstrated that mitogen-activated protein kinase (MAPK) cascades are major pathways that transduce extracellular stimuli, including various stresses, into cellular responses. MAPK is activated by dual phosphorylation of threonine and tyrosine residues in a TXY motif located between subdomains VII and VIII of the kinase catalytic domain by MAPK kinase (MAPKK). MAPKK is, in turn, activated by MAPKK kinase (MAPKKK). Multiple MAPK cascades that carry out different functions are present in a single cell.

SIPK and WIPK, two members of the tobacco MAPK family are activated differentially by various stresses, including wounding and pathogen infection. The primary goal of this lab is to define the in vivo function of these two MAPKs by using a combination of biochemical, molecular and genetic approaches. While the components of a plant MAPK cascade are very similar to those of yeast and mammals, plant MAPKs adopt different function and regulation during the evolution. For instance, elevation of WIPK activity in pathogen-infected cells requires both post-translational phosphorylation and a preceding gene transcription and de novo synthesis of WIPK protein. In contrast, all yeast and mammalian MAPKs pre-exist in cells and require only phosphorylation activation. Very interestingly, induction of WIPK mRNA and protein also occur systemically and correlates with the establishment of systemic acquired resistance (SAR).

By understanding, at molecular and cellular levels, how plants protect themselves under adverse environmental conditions, such as a pathogen attack, we could eventually identify suitable targets for genetically engineering of crops with enhanced disease resistance.

Selected publications

Beckers G.J., Jaskiewicz M., Liu Y., Underwood W.R., He S.Y., Zhang S., and Conrath U. (2009) Mitogen-activated protein kinases 3 and 6 are required for full priming of stress responses in Arabidopsis thaliana. Plant Cell 3: 944-53.

Jang E.K., Min K.H., Kim S.H., Nam S.H., Zhang S., Kim Y.C., Cho B.H., and Yang K.Y. (2009) Mitogen-activated protein kinase cascade in the signaling for polyamine biosynthesis in tobacco. Plant Cell Physiol. 3: 658-64.

Wang, W., Liu, Y., Bruffett, K., Lee, J., Hause, G., Walker, J.C., and Zhang, S. (2008) Haplo-insufficiency of MPK3 in MPK6 mutant background uncovers a novel function of these two MAPKs in Arabidopsis ovule development. Plant Cell 20: 602-613.

Cho, S.K., Larue, C., Wang, H., Chevalier, D., Jinn, T.-L., Zhang, S., and Walker, J.C. (2008) Regulation of Floral Organ Abscission in Arabidopsis thaliana. Proc. Natl. Acad. Sci. USA 105: 15629-15634.

Hord, C.L.H., Sun, Y., Pillitteri, L.J., Torii, K.U., Wang, H., Zhang, S., and Ma H. (2008) The mitogen-activated protein kinases, MPK3 and MPK6, and the ERECTA and related receptor-like kinases are important for Arabidopsis anther development. Molecular Plant 1: 645-658.

Ren, D., Liu, Y., Yang, K.-Y., Han, L., Mao, G., Glazebrook, J., and Zhang, S. (2008) Fungal-responsive mitogen-activated protein kinase cascade in signaling phytoalexin biosynthesis in Arabidopsis. Proc. Natl. Acad. Sci. USA 105: 5638-5643.

Joo, S., Liu, Y., Lueth, A., and Zhang, S. (2008) MAPK phosphorylation-induced stabilization of ACS6 protein is mediated by non-catalytic C-terminal domain, which also contains the cis-determinant for rapid degradation by the 26S proteasome pathway. Plant Journal 54: 129-140.

Underwood, W., Zhang, S., and He, S.-Y. (2007) The Pseudomonas syringae type III effector tyrosine phosphatase HopAO1 suppresses innate immunity in Arabidopsis thaliana. Plant Journal 52: 658-672.

Liu, Y., Ren, D., Pike, S., Pallardy, S., Gassmann, W., and Zhang, S. (2007) Chloroplast-generated reactive oxygen species are involved in hypersensitive response-like cell death mediated by a mitogen-activated protein kinase cascade. Plant Journal 51: 941-954.

Employment opportunities

Postdoctoral opportunities

Research areas: MAP kinases and signaling in plant defense responses.

How to apply:

Electronic submission is encouraged, e-mail to zhangsh@missouri.edu

Applicants should send CV and names of two references to:
Dr. Shuqun Zhang
Christopher S. Bond Life Sciences Center
371G Bond Life Sciences Center
University of Missouri
Columbia, MO 65211