Figure 11.

JNK activation causes an increase in AUF1. Neonatal rat cardiomyocytes were infected with Ad-d1312 (control, CV), Ad-MKK7D (7D), or Ad-MKK6E (6E) for 72 hours. Cell extracts were analyzed by Western blot methods using anti-AUF1 as a probe. (A) A representative Western blot is shown with the four bands corresponding to AUF1 alternatively spliced forms, p37, p40, p42, p45 (11). (B) Summary data of AUF1 protein levels in which the sum of densities of the four bands were normalized to the values in the control cultures (means ± SEM, n=4 for MKK7D cells, n=3 for MKK6E cells, * p<0.05). (C) B56α protein was quantified in parallel experiments. The summary data values are shown below as percent decrease compared to the control (means ± SE).

D. Neonatal rat cardiomyocytes were treated with 0.2 μmol/L PMA, 5% fetal bovine serum (FBS), or 1μg/ml LPS for 72 hrs. Control non-treated cells were cultured for 72 hours. Cells were homogenized in a lysis buffer containing 1% Triton-X and cell extracts were separated in a 10% SDS-polyacrylamide gel and transferred to a nitrocellulose membrane and were probed with anti-AUF1 (top panel) or anti-B56α (bottom panel).