Regulation of Renal Organic Anion Transporter 3 (SLC22A8) Expression and Function by the Integrity of Lipid Raft Domains and their Associated Cytoskeleton

作者：Chutima Srimaroeng, Jennifer Perry Cecile, Ramsey Walden, John B. Pritchard · 发表于：Cellular Physiology and Biochemistry · 年份：2013 · DOI：10.1159/000350077 · 被引用次数：2992 · 研究领域：Ion Transport and Channel Regulation、Drug Transport and Resistance Mechanisms、Caveolin-1 and cellular processes

BACKGROUND/AIMS: In humans and rodents, organic anion transporter 3 (Oat3) is highly expressed on the basolateral membrane of renal proximal tubules and mediates the secretion of exogenous and endogenous anions. Regulation of Oat3 expression and function has been observed in both expression system and intact renal epithelia. However, information on the local membrane environment of Oat3 and its role is limited. Lipid raft domains (LRD; cholesterol-rich domains of the plasma membrane) play important roles in membrane protein expression, function and targeting. In the present study, we have examined the role of LRD-rich membranes and their associated cytoskeletal proteins on Oat3 expression and function. METHODS: LRD-rich membranes were isolated from rat renal cortical tissues and from HEK-293 cells stably expressing human OAT3 (hOAT3) by differential centrifugation with triton X-100 extraction. Western blots were subsequently analyzed to determine protein expression. In addition, the effect of disruption of LRD-rich membranes was examined on functional Oat3 mediated estrone sulfate (ES) transport in rat renal cortical slices. Cytoskeleton disruptors were investigated in both hOAT3 expressing HEK-293 cells and rat renal cortical slices. RESULTS: Lipid-enriched membranes from rat renal cortical tissues and hOAT3-expressing HEK-293 cells showed co-expression of rOat3/hOAT3 and several lipid raft-associated proteins, specifically caveolin 1 (Cav1), β-actin and myosin. Moreover, im...