The primary interest of our lab is to understand the mechanisms that cells have developed to move ions and small molecules across cell membranes. This work has also led us to investigate the mechanisms whereby mutations in certain transporters or ion channels lead to specific pathological conditions. P-type ATPases are primary active transport proteins that are responsible for establishing many of the ion gradients that exist across both eukaryotic and prokaryotic cell membranes. A major theme in our lab for many years has been the investigation of the structure and mechanism of the Na,K-ATPase, the Ca-ATPase from sarcoplasmic reticulum, and the H,K-ATPase of gastric mucosa. In another line of investigation, we are studying the mechanisms of serotonin and GABA transport by neuronal serotonin and GABA transporters. These transporters are members of a class of proteins that couple neurotransmitter uptake to the transport of sodium ions and often to other ions as well. These transporters are targets of both clinically useful drugs such as SSRIs used to treat depression and also drugs of abuse such as cocaine and methamphetamine. The serotonin transporter, in particular, exhibits characteristics of both an alternating access transporter and an ion channel, and we are interested to know how this observation can be explained. Over the past three or four years our lab has also begun to investigate the mechanisms of selective ion permeation through ion channels of both bacterial and animal cell membranes. Loss of ion selectivity is sometimes linked to mutations in the genes for ion channels that cause different forms of pathology.
Our work on the structure and mechanism of each of these transporters and channels has historically used techniques of membrane protein biochemistry, multiple types of spectroscopy, electrophysiology, and molecular biology. As more atomic level structures of transport proteins have become available over the past 10-15 years, we have moved primarily to using molecular dynamics simulations of these transporters as a tool to elucidate dynamic mechanistic details. These details are not usually captured by static protein structures and are often inaccessible to direct experimental measurement.
March 22, 2017
Congratulations to Yi who successfully defended her M.S. thesis today.
March 16, 2017
Kudos to Sarah who successfully defended her M.S. thesis today.
September 22, 2016
Lab outing: Dodger baseball game
August 31-September 4, 2016
Lab outing: Backpack trip to the Eastern Sierra Nevada mountains
August 22, 2016
We are happy to welcome Charlie Hoying (Loyola Marymount University) to the lab as a new graduate student.
April 28, 2016
Congratulations to Melia Tabbakhian (M.S., 2013) on her appointment as Professor of Anatomy and Physiology at Moorpark College.
March 1, 2016
Yi and Sarah presented a poster about their project at the 60th Annual Meeting of the Biophysical Society today in Los Angeles.