Mark A. Knepper 2026-11-05
Mark A. Knepper is a researcher in kidney physiology who uses systems biology to investigate the regulation of water transport. A central example is how vasopressin changes the distribution of aquaporin-2 between the plasma membrane and the interior of collecting duct cells. His 2010 research report describes combining mass spectrometry, measurements of gene expression, mathematical modeling and physiological experiments to investigate this regulation.[ref]
The timing gives the mechanism its interest. On a scale of seconds to minutes, membrane trafficking can move existing aquaporin-2 into the plasma membrane, changing the route available for water movement. That is a different regulatory step from making additional aquaporin-2 through altered gene expression. Measuring how much channel protein exists and where it is located therefore answers different questions.[ref]
Mark A. Knepper also wrote a scientific remembrance of Maurice B. Burg, explaining how experiments on isolated renal tubules opened individual transport mechanisms to direct investigation.[ref]
Verified locator: PNAS119(30),e2209749119(2022); primary colleague-authored remembrance by MarkA.Knepper, published15July2022. Opening:1931–2022, death24April2022, isolated-perfused-nephron method and physiological importance. Indexed primary article text inspected; direct fetch may show a browser challenge.