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Xuanzhi Zhan, PhD

Post-doctoral fellow, Pharmacology


Education

2003-2008 Ph.D. Biochemistry, Auburn University

1998-2001 M.S. Biochemistry & Molecular Biology, School of life science, East China Normal University.

1994-1998 B.S. Biochemistry, Department of Biology, East China Normal University.

Research Description

Xuanzhi joined the lab in 2008. In 2014 he accepted an offer of Assistant Professor in Chemistry position at Tennessee Tech University

He was studying the molecular mechanisms of arrestin interaction with non-receptor signaling proteins, focusing on kinases ASK1, MKK4/7, and JNK1/2/3. Xuanzhi had placed a strong emphasis on reconstruction of arrestin-mediated JNK signaling pathways with purified proteins. By studying these JNK activation cascades under the strictly controlled reconstructed systems, Xuanzhi found that arrestin-3 facilitates JNK activation as a true scaffold protein by tethering kinase components and bringing them close together. Because of that, JNK activation demonstrated a biphasic dependent on arrestin-3 concentration. These interesting observations lead to another surprising finding that arrestin-3 facilitates not only the activation of JNK3 by MKK4, but also by MKK7. Moreover, Xuanzhi discovered that JNK3 binding differentially affects the interaction of the two MKKs with arrestin-3, enhancing the binding of MKK4 and suppressing that of MKK7. This is the first demonstration that MAP kinases regulate each other’s interactions with arrestin-3. It was widely believed that arrestin-3 facilitates the activation only of the neuro-specific JNK3. Xuanzhi proved that arrestin-3 directly binds two ubiquitously expressed JNK isoforms: JNK1 and JNK2, even though neither JNK1 nor JNK2 contains previously identified arrestin-3 binding element present in JNK3.

There is a lot of direct and indirect evidence that arrestins undergo significant conformational changes upon associating with their binding partners. These binding-induced conformational changes could play decisive roles to prevent arrestin from simultaneous binding of mis-matched partners, which would create non-productive complexes. To explore the structural basis of these arrestin functions, Xuanzhi solved the crystal structure of arrestin-3. Two powerful molecular tools were developed based on the structure: cysteine-free arrestin-3 and a set of MBP-fusion proteins containing arrestin-3 fragments covering the non-receptor-binding surface of arrestin-3. Xuanzhi identified three JNK3 binding elements on both domains of arrestin-3. These MBP-fusion proteins are suitable for identifying the binding sites of many other partners of arrestin-3. Currently, Xuanzhi is employing several biophysical methods to explore the binding-induced conformational changes of arrestin.

The ultimate goal of these studies is to gain sufficient mechanistic insight into arrestin-mediated JNK activation to design molecular tools with desired signaling properties. Xuanzhi discovered a small peptide-scaffold of JNK3: he showed that a 25-residue element of arrestin-3 acts as a scaffold, facilitating the activation of JNK3 in cells. He found that this small peptide binds each kinase in ASK1-MKK4/7-JNK3 signaling module. Xuanzhi is elucidating the structural basis of peptide-mediated scaffolding by identifying the critical residues for facilitating JNK3 activation, as well as for its interactions with JNK3 and its upstream kinases ASK1, MKK4, and MKK7. Short peptide scaffolds will become powerful molecular tools for manipulation of JNK activity in cells. Since JNK family kinases are implicated in cell death, differentiation, and numerous human disorders, these tools have tremendous therapeutic potential.

Xuanzhi has many papers and chapters from the lab in Medline.

Publications (we publish a lot, so search Medline for an update)

Kook, S., Zhan, X., Thibeault, K., Ahmed, M.R., Gurevich, V.V., Gurevich, E.V. Mdm2 enhances ligase activity of parkin and facilitates mitophagy. Sci Rep 10 (1) 5028; doi: 10.1038/s41598-020-61796-4 (2020).

Perry, N.A., Zhan, X., Gurevich, E.V., Iverson, T.M., Gurevich, V.V. Using in vitro pull-down and in cell overexpression assays to study protein interactions with arrestins. In: Beta-arrestins, S. Laport, Ed. Springer-Verlag, Berlin-Heidelberg (2019).

Perry, N.A., Kaoud, T.S., Ortega, O.O., Kaya, A.I., Marcus, D.J., Pleinis, J.M., Berndt, S., Chen, Q., Zhan, X., Dalby, K.N., Lopez, C.F., Iverson, T.M., Gurevich, V.V. Arrestin-3 scaffolding of the JNK3 cascade suggests a mechanism for signal amplification. Proc Natl Acad Sci USA, in press (2019).

Zhan, X., Gurevich, V.V., Gurevich, E.V. Scaffolding c-Jun N-terminal kinase cascades: mechanistic insights from the reconstituted arrestin-JNK cascades. Ch 14 in The structural basis of arrestin functions. Springer-Verlag, Berlin-Heidelberg, ISBN 978-3-319-57552-0 (2017).

Spiller, B.W., Zhan, X., Gurevich, V.V. Arrestin-3: the structural basis of lower receptor selectivity. Ch 5 in The structural basis of arrestin functions. Springer-Verlag, Berlin-Heidelberg, ISBN 978-3-319-57552-0 (2017).

Zhan, X., Stoy, H., Kaoud, T.S., Perry, N.A., Chen, Q., Perez, A., Els-Heindl, S., Slagis, J.V., Iverson, T.M., Beck-Sickinger, A.G., Gurevich, E.V., Dalby, K.N., Gurevich, V.V. Peptide mini-scaffold facilitates JNK3 activation in cells. Sci Rep 6, 21025; doi: 10.1038/srep21025 (2016).

Zhan, X., Kook, S., Kaoud, T.S., Dalby, K.N., Gurevich, E.V., and Gurevich, V.V. 2015. Arrestin-3-Dependent Activation of c-Jun N-Terminal Kinases (JNKs). Curr Protoc Pharmacol 68:2.12.1-2.12.26. doi: 10.1002/0471141755.ph0212s68 (2015).

Vishnivetskiy S.A., Zhan, X., Chen, Q., Iverson, T.M., Gurevich VV. Arrestin expression in E. coli and purification. Curr Protoc Pharmacol 67, 2.11.1-2.11.19 (2014).

Zhuo, Y., Vishnivetskiy, S.A., Zhan, X., Gurevich, V.V., Klug, C.S. Identification of receptor binding-induced conformational changes in non-visual arrestins. J Biol Chem 289 (30), 20991-21002 (2014).

Zhan, X., Perez, A., Gimenez, L.E., Vishnivetskiy, S.A., Gurevich, V.V. Arrestin-3 binds the MAP kinase JNK3a2 via multiple sites on both domains. Cell Signal 26 (4), 766-776 (2014).

Kook, S., Zhan X., Cleghorn, W.M., Benivic, J.L., Gurevich, V.V., Gurevich, E.V. Caspase-cleaved arrestin-2 and BID cooperatively facilitate cytochrome C release and cell death. Cell Death Differ 21 (1), 172-84 (2014)

Zhan, X., Kook, S., Gurevich, E.V. and Gurevich, V.V. Arrestin-dependent activation of JNK family kinases. In: Arrestins – Pharmacology and Therapeutic Potential. Handb Exp Pharmacol 219, p. 259-280, Springer-Verlag, Berlin-Heidelberg (2014).

Kook, S., Zhan, X., Kaoud, T.S., Dalby, K.N., Gurevich, V.V., Gurevich, E.V. Arrestin-3 binds c-Jun N-terminal kinase 1 (JNK1) and JNK2 and facilitates the activation of these ubiquitous JNK isoforms in cells via scaffolding. J Biol Chem 288 (52), 37332-37342 (2013).

Zhan, X., Kaoud, T.S., Kook, S., Dalby, K.N., Gurevich, V.V. JNK3 enzyme binding to arrestin-3 differentially affects the recruitment of upstream mitogen-activated protein kinase kinases. J Biol Chem 288 (40), 28535-28547 (2013).

Kim, M., Vishnivetskiy, S.A., Van Eps, N., Alexander, N.S., Cleghorn, W.M., Zhan, X., Hanson, S.M., Morizumi, T., Ernst, O.P., Meiler*, J., Gurevich*, V.V., Hubbell*, W.L. (*corresponding authors) Conformation of receptor-bound visual arrestin. Proc. Natl. Acad. Sci. USA 109, 18407-18412 (2012).

*Zhan, X., Kaoud, T.S., Dalby, K.N., Gurevich, V.V. Non-visual arrestins function as simple scaffolds assembling MKK4-JNK3a2 signaling complex. Biochemistry 50, 10520-10529 (2011). *Highlighted on the Biochemistry home page.

Ahmed, M.R., Zhan, X., Song, X., Kook, S., Gurevich, V.V., Gurevich, E.V. Ubiquitin ligase parkin promotes Mdm2-arrestin interaction but inhibits arrestin ubiquitination. Biochemistry 50, 3749-3763 (2011).

Zhan, X., Gimenez, L.E., Gurevich, V.V., Spiller B.W. Crystal structure of arrestin-3 reveals the basis of the difference in receptor binding between two non-visual subtypes. J Mol Biol 406, 467-478 (2011)