Meeting Abstract

35.6  Friday, Jan. 4  Proteome Fingerprint of the Stress Environment in the Renal Papilla GABERT, B.J.**; K�LTZ, D.; University of California, Davis bjlandgraf@ucdavis.edu

The mammalian kidney generates a large and variable osmotic gradient to generate urine with a much higher osmotic concentration than blood. This vital function of the kidney is only possible at the cost of creating a very hostile environment in the renal papilla. Because of its osmotically very stressful environment the renal papilla represents a powerful model for investigating the molecular and cellular adaptations to hyperosmolality. We utilized this model for a proteomic approach to investigate the unique proteins and cellular pathways that are characteristic to the hyperosmotic papilla of the mouse kidney in comparison to the kidney cortex, an isoosmotic region. While functionally distinct, these regions are in close physical proximity. Two-dimensional gel electrophoresis was used to generate a proteome map for each kidney region. The resulting patterns were compared by Delta2D software to quantify expression of more than 1500 proteins (n = 6) allowing detection of 212 cortex proteins and 80 papilla proteins with a two-fold or greater difference between the regions. MALDI-TOF/TOF mass spectrometry was then used to sequence and identify proteins that are over- and under-represented in kidney papilla relative to cortex. These protein sets were subsequently submitted to PANTHER (protein analysis through evolutionary relationships) analysis to determine cellular functions, biological processes and molecular pathways that correlate with the hyperosmotic environment experienced by the kidney papilla. Our data provide new insight into biochemical adaptations supporting cell function under the stressful conditions found in the kidney papilla.