Overview

Chris Yun, PhD joined Emory University in 2002. Prior to that, he received a PhD in biophysics from the University of Illinois at Urbana-Champaign and completed postdoctoral training at Johns Hopkins in electrolyte transport. He was promoted to an assistant professor at Hopkins, where he established an independent research career.

In mammalian intestines, NHE3 is a component of electroneutral NaCl absorption, which is a major constituent in basal Na+ and fluid absorption and this is a frequent target of inhibition in many diarrheal diseases. Another site of NHE3 is kidney where 70% of HCO3- reabsorption can be attributed to Na+/H+ exchanger NHE3. NHE3 is regulated by hormones, growth factor, and external stimuli that target protein kinases. The first goal is understand the mechanisms of NHE3 regulation by G protein-coupled receptors and protein kinases. The second goal is to delineate how the interaction of NHE3 with accessory proteins (NHERF1, NHERF2, and IRBIT) affects the signaling targeting NHE3. Dr. Yun's lab is focusing on the cellular signaling elicited by glucocorticoids, angiotensin and lysophosphatidic acid (LPA).

In another project, Dr. Yun's team is investigating the role of LPA in colorectal cancer. LPA is a lipid mediator with diverse biological properties such as proliferation, apoptosis, contraction, migration, and aggregation. The effects of LPA are mediated by the G protein-coupled receptors; LPA1, LPA2 and LPA3. The first indication that LPA could contribute to tumorigenesis came from studies showing that LPA increases motility and invasiveness of cells. LPA levels are significantly increased in malignant ascites, and its receptors are aberrantly expressed in ovarian cancer. In addition, their recent study has shown that LPA2 is over-expressed in several cancers, including colon, testis, uterus, and rectum.

In addition, they have recently demonstrated that cellular signaling by LPA2 is mediated through its interaction with scaffold proteins, such as NHERF2 and MAGI-3. The goals of this project are to understand the role of LPA and LPA2 receptor in colorectal cancer and the role of scaffold proteins regulation of cellular signaling by LPA2.

Dr. Yun is a coordinator of the basic research seminars for the Division of Digestive Diseases. He is a member of BCDB and NHS programs at Emory University. He is currently one of coordinators fro BCDB 570r.

Member of the Faculty Development Committee of DOM. Chair of the Grant Review Committee. Member of the Editorial Board for Am J Physiol-GI. Member of the Research Award Review Panel of American Gastroenterology Association. Ad hoc reviewer for NIH study sections. Member of the CIMG study section at NIH. Member of the Abstract Review Committee for American Gastroenterological Association. Reviewer for more than 10 journals.

Academic Appointment

• Profesor of Medicine, Medicine/ Digestive Diseases, Emory University

Education

Research