Fig. 1
Generation and validation of the PA28αOE mouse model. a Structure of the targeting vector, targeted allele and KI allele (PA28αOE). b Representative western blots of PA28α in cultivated mouse embryonic fibroblasts (MEFs), frontal cortex and striatum (brain), eye lens and left ventricle of the heart and representative western blots of PA28β in MEFs and frontal cortex and striatum (brain) from litter mates of PA28αOE (OE) and wildtype (WT) C57BL/6 male mice (founder strain). Analysis demonstrated that PA28α is induced fivefold in MEFs (P < 1E−5; Student’s t test), 3.2-fold in brain (P < 0.001), 15-fold in eye lens (P = 0.0049), and fourfold in heart (P < 1E−6), while PA28β is induced 2.7-fold in brain (P = 0.0015) (n = 3). The amount of PA28β was below detection level in WT MEFs, but detected in all OE MEFs (n = 3). c Relative levels of mRNA encoding PA28α and PA28β with 36b4 as a reference gene in a mixed sample of frontal cortex and striatum of the brain. Values are mean ± SEM normalized to mean WT-value (PPA28α= 0.028; n = 3). Two different splicing variants of the PA28β transcript were analyzed