Fig. 2. Erasin is widely expressed in different tissues. (A) A schematic drawing of the erasin protein. The inferred erasin ORF consists of 508 amino acids. The protein contains a UBX domain from residues 316 to 395 (striped). The probes used in northern blot assay are indicated. Also shown are the two regions against which rabbit polyclonal anti-erasin antibodies 130 and 141 were raised. (B) Northern blot of ERASIN mRNA expression in multiple human tissues. After stripping, the blot was reprobed with ß-actin. The level of ERASIN mRNA expression relative to that in the lung is shown after normalization for actin loading. (C) Characterization of anti-erasin antibodies. Endogenous erasin protein in HeLa cell lysates detected with anti-erasin antibodies 130 and 141. Both antibodies detected a major 64 kDa band that was not detected by their respective preimmune sera (for the preimmune 141 serum see Fig. 6A lane 1). (D) Peptide competition assay demonstrating specificity of antibody 141. Same procedure as Fig. 2C, except antibody 141 was pre-incubated with 0-1 mg/ml of its cognate peptide for 2 hours before immunoblotting. (E) Protein lysates of HeLa cells mock transfected (Control), or transfected with FL untagged erasin, or a C-Myc-tagged erasin expression constructs immunoblotted with anti-erasin 141 (top panel), anti-Myc (middle panel) and anti-actin (bottom panel) antibodies. (F) Immunoblots showing endogenous erasin protein levels in different human cell lines revealed by anti-erasin antibody. (G) Equal amounts of protein lysates from different mouse tissues immunoblotted for erasin with antibody 141 (upper panel) and subsequently with an anti-actin antibody (lower panel).