Monday . . . . 10:00 - 11:00
Tuesday . . . . 10:00 - 11:00
Wednesday . .
Thursday. . . .
Friday. . . . . . Others by appt.
Biographical Information:Paul James is a molecular physiologist who uses a synthesis of molecular biology, cell biology, biochemistry, and physiology to try to understand the specific in vivo functional roles of individual proteins (isoforms) that transport ions across membranes. Specifically, he is interested in using knockout and transgenic mice to define the roles that isoforms of the Na,K-ATPase play in the contractility of the heart and in the motility of sperm. Using knockout mice, a specialized role for the Na,K-ATPase alpha2 isoform was uncovered in the heart: uniquely, this isoform works in concert with the Na/Ca exchanger and the sarcoplasmic reticulum to regulate the intracellular calcium levels and therefore cardiac contractility. Using inhibition studies, a critical role for the Na,K-ATPase alpha4 isoform was identified in the maintenance of sperm motility: it appears that this isoform regulates the intracellular H+ concentration in sperm by supporting the activity of the Na/H exchanger, a transporter that clears excess protons generated by the mitochondria from the mid-piece of the sperm.
Currently in the laboratory, students use a host of modern biological techniques (including Southern, northern, and western blots, the polymerase chain reaction - PCR, and transgenic and knockout technology) to generate and express chimeric Na,K-ATPase isoforms (isoforms containing parts from two different isoforms) in order to understand the molecular basis for the unique functional roles of these individual transporters.