Figure 3.
(a) Western blot of proteins extracted from glomeruli isolated from Ptpro–/–, Ptpro+/–, and Ptpro+/+ mice. The GLEPP1 band is at 180 kDa. Bands at lower molecular weights are nonspecific and were seen at the same intensities on a control blot developed with preimmune Ab’s (not shown). Numbers below lanes correspond to micrograms of glomerular Triton protein extract loaded onto each lane. Ptpro+/+ extract was loaded at twofold serial dilutions from the right side of the gel and could be detected at the 32-fold dilution. GLEPP1 was not detectable in Ptpro–/– extracts. GLEPP1 was present in Ptpro+/– extracts at a level approximately one-half that of extracts from Ptpro+/+ mice. (b) Northern blot of RNA prepared from glomeruli isolated from Ptpro+/+, Ptpro+/–, and Ptpro–/– mice. Left panel: probed with 1 kb human GLEPP1 intracellular domain, random-primed DNA labeled with α-32P dCTP. Right panel: probed with human β-actin probe to show equal loading of RNA onto the lanes. No detectable hybridization was seen in the Ptpro–/– RNA sample.