FIGURE 7.

Tissue distribution of GP-NAE phosphodiesterase activity and GDE1. A, GP-NAE phosphodiesterase activity in membrane fractions of mouse tissues. Assays were performed with 100 μm [1′-¹⁴C]N-C16:0 GP-NAE substrate, where the release of [1′-¹⁴C]N-C16:0 NAE was measured by thin layer radiochromatography. B, Western blot of GDE1 expression in membrane fractions of mouse tissues following treatment with PNGase F showing strong correlation with GP-NAE phosphodiesterase activity. C, reverse transcription-PCR analysis of GDE1 mRNA expression correlates with GDE1 protein levels and GP-NAE phosphodiesterase activity. The ubiquitously expressed enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as a control to confirm integrity of tissue cDNA. Br, brain; Spc, spinal cord; Ht, heart; Lv, liver; Kd, kidney; Spln, spleen; Ts, testis.