Xuehua (Ivy) Wan
2538 McCarthy Mall, Snyder Hall 111
Honolulu, HI 96822
(808) 956-6945 (phone)
(808) 956-5339 (fax)
xuehua@hawaii.edu

Education

Research Summary

If asked what bacterial life is, what will come to your mind? You might think those tiny simplest unicellular creatures live as individual cells.  However, life is complicated and bacteria are not excluded. Surprisingly, like human beings, bacteria also talk to each other and have a very rich social life. They prefer to grow in surface-associated community, which is called biofilm.  In my studies, I’m asking what signal transduction networks contribute to the swing between the planktonic cell and the sessile community.    
 

I’m currently working on characterization of bacterial globin coupled diguanylate cyclases (GCDC) which synthesize a small RNA molecule cyclic dimeric guanosine monophosphate (c-di-GMP). Bacteria use various small molecules for signaling. One of them, c-di-GMP, which was discovered almost two decades ago, is now excitingly recognized as a novel global second messenger in bacteria. New sensing-signaling mechanisms mediated by second messenger c-di-GMP have been proposed for bacterial motility inhibition, exopolysaccharide production, virulence and biofilm formation. I’m trying to understand what the signals for these GCDCs are and how they work.

Schematic diagram of c-di-GMP metabolism and some of its known effects.

Publications

Saito JA, Wan X, Lee KS, Hou S, Alam M.  2008.  Globin-coupled sensors and protoglobins share a common signaling mechanism.  FEBS Lett.  In press.

Thijs L, Vinck E, Bolli A, Trandafir F, Wan X, Hoogewijs D, Coletta M, Fago A, Weber RE, Doorslaer SV, Ascenzi P, Alam M, Moens L, & Dewilde S.  2007.  Characterization of a globin-coupled oxygen sensor with a gene-regulating function.  J. Biol. Chem.  282: 37325-37340.

Freitas TAK, Saito JA, Wan X, Hou S, & Alam M.  2007.  Protoglobin and globin-coupled sensors.  In Ghosh, A. (Ed.)  The smallest biomolecules: diatomics and their interactions with heme proteins.  pp. 175-202.