Lysosomal integral membrane protein type 2 (LIMP-2) is a lysosomal transmembrane protein that has been identified as a mannose-6-phosphate independent trafficking receptor for beta-glucocerebrosidase. Mutations in the SCARB/LIMP-2 gene cause Action-myoclonus renal failure syndrome (AMRF) associated with proteinuria. LIMP-2 deficient mice have proteinuria, too and an increased excretion of dilute urine. Since little is known about the intrarenal localization of LIMP-2, immunofluorescence staining was performed in mouse kidneys using a specific LIMP-2 antibody. While a clear punctate staining pattern was observed in kidneys of wildtype mice, the LIMP-2 antibody did not produce any staining in LIMP-2 deficient kidneys, indicating its specificity. By far the strongest renal LIMP-2 immunoreactivity was found in the renin producing juxtaglomerular cells located in afferent arterioles. Vascular smooth muscle cells of renal arterioles showed clear LIMP-2 labeling. While only very faint immunoreactivity was detected in endothelial cells of arterioles, cortical and medullary peritubular capillaries showed a robust punctate LIMP-2 expression. In the glomeruli LIMP-2 immunoreactivity was found in mesangial cells, while no significant colocalization with podocin or synaptopodin (markers for podocytes) was detectable. In the tubular system the strongest LIMP-2 staining was found in the proximal tubule, while no immunoreactivity was found in collecting ducts. Despite of the striking expression level of LIMP-2 in renin producing cells, plasma renin concentration of LIMP-2 deficient mice was not different compared to wildtypes under control conditions. Ongoing studies will clarify the functional role of LIMP-2 in the kidney and especially in renin producing cells.