Research interests

The main research interest of Yoon laboratory is to explore the Wnt signaling pathways to understand how cell specification/differentiation and morphogenesis processes are regulated during normal embryonic and postnatal development, and how aberrant regulation of these processes leads to the disease conditions in postnatal stage.

In one project, we are studying the biological roles and signaling mechanisms of the R-spondin family of proteins recently discovered in our laboratory. We found that R-spondins are a novel class of specific ligands for the Wnt signaling receptors, Frizzled8 and LRP6, and activate the beta-catenin-dependent Wnt signaling pathway. We are currently investigating the function of the R-spondin genes during mouse embryogenesis and postnatal development, utilizing genetically modified mice and cell culture model.

In another project, we are interested in studying molecular and cellular roles of receptor tyrosine pseudokinse, PTK7, in the non-canonical Wnt signaling pathway. Mice lacking a functional PTK7 gene display defects associated with disregualtion of planar cell polarity (PCP) pathway, a branch of the non-canonical Wnt signaling pathway. Current investigation is focused on determining how PTK7 regulates non-canonical Wnt signaling using proteomics, genetics and biochemical approaches.

 

Publications

• Kim, D.J., Park C.S., Yoon, J.K*. and Song W. K.* Differential Expression of the Wnt and Frizzled genes in Flk+ cells derived from mouse ES cells. Cell Biochemistry and Function, 26: 24-32 (2008).
• Ishii Y., Wajid M., Bazzi H., Fantauzzo K.A., Barber A.G., Blaydon D.C., Nam J.S., Yoon J.K., Kelsell D.P., and Christiano, A.M. Mutations in R-spondin 4 (RSPO4) underlie inherited anonychia. J. Invest. Dermatol. 128:867-870 (2008).
• Venkatesh D.A., Park K.S., Harrington A, MiceliLibby L, Yoon J.K. and Liaw L. Cardiovascular and hematopoietic defects associated with Notch1 activation in embryonic Tie2 expressing populations. Circulation Research 103:423-431 (2008).
• Nam, J.S., Turcotte, T.J. and Yoon, J.K. Dynamic expression of R-spondin family of genes in mouse development. Gene Expression Patterns 7:306-312 (2007).
• Nam J.S., Park, E., Turcotte, T.J., Palencia S., Zhan X., Lee J., Yun K., Funk W.D.*, and Yoon J.K.* Mouse R-spondin2 is required for apical ectodermal ridge maintenance in the hindlimb. Developmental Biology 311: 124-135 (2007).
• Nam, J.S., Turcotte, T.J., Smith, P., Choi, S. and Yoon, J.K. Mouse Cristin/R-spondin family proteins are novel ligands for the Frizzled8 and LRP6 receptors and activate beta-catenin-depedent gene expression. J. Biol. Chem. 281:13247-13257 (2006).
• Durmus, T., LeClair, R.J., Park, K.S., Terzic, A. Yoon, J.K. and Lindner, V. Expression Analysis of the Novel Gene Collagen Triple Helix Repeat Containing-1 (Cthrc1). Gene Expression Patterns 6:935-940 (2006).