Dr. Jack Kaplan, PhD, F.R.S.
Professor Emeritus
- AAAS Fellow (2014)
- PhD in Biophysics from the University of London, in 1973
- Max Planck Society Post-Doctoral Fellow at the Max Planck Institute
for Biophysics Frankfurt, Germany, 1973-75
Research Interests:
Structure-function studies, mechanism, biosynthesis, assembly and cellular trafficking of P-type ATPases or Ion pumps. Mechanism and Regulation of Copper transport systems in Human Cells.
The active transport of ions across cell membranes is performed by P-type ATPases. These are integral membrane proteins which use the energy of hydrolysis of ATP to pump ions across biological membranes. The mechanism by which these proteins couple ATP hydrolysis to ion transport is one of the central interests of the laboratory. These proteins form phosphorylated intermediates with ATP and transport Na+, K+, H+, Ca2+, Cu2+, Cd2+ etc. across animal, bacterial, and plant cell membranes.
Using baculovirus-infected insect cells to express mutant Na pump molecules we are now studying protein conformational changes using site directed fluorescence and how the sub-units assemble in the ER and are trafficked via the Golgi to the plasma membrane using cell fractionation, immunological and metabolic labelling techniques. We are also interested in studying how Cu ions enter cells and we are carrying out the molecular analysis and characterization of hCTR1 a protein which mediates the entry of Cu ions into human cells. In this program we are employing the baculovirus-infected insect cell lines to generate recombinant transporter protein for structure-function and regulation studies.
During the last twenty years, we have been responsible for the introduction and development of caged compounds for biophysical and physiological studies. These are novel photolabile compounds which on u-v illumination release the caged substrate (ATP, ADP, Pi, Ca2+, Mg2+, etc.) in the msec-microsec time range and thus synchronously and rapidly initiate biological processes. We plan to continue to develop this strategy to provide novel photorelease techniques for cellular and molecular studies.
