Zn is essential for the proper functioning of over 200 enzymes and plays a major role in genetic expression, cell division and growth. Poly (ADP-ribose) polymerase (PARP) is a zn containing enzyme that is important in cell differentiation, gene expression and DNA replication and repair. Dialysis of PARP, under a variety of conditions, indicate that a decrease in zn content of the enzyme is associated with a decrease in activity. We hypothesized that a nutritional zn deficiency would result in decreased PARP activity. 3T3 fibroblasts were grown in media with varying levels of zn (0.5, 6, 15, 45 and 90 μM). The cells were grown in the experimental media for 48 h and harvested during log phase growth. PARP activity was determined by measuring the incorporation of [32P]NAD into acid-insoluble acceptors at 25°C for 10 min. PARP protein was assessed by western blot analysis. Activity was found to be positively correlated with media zn concentration (r2-.92). Cells grown in zn deficient media (0.5μM zn) had PARP activity 1/10th the activity of cells grown in media containing 90μM zn. PARP activity showed a dose dependent effect in response to media zn. Cells grown in 90μM zn had the same PARP activity as cells grown in 10% FBS. Preliminary western analysis indicated decreased levels of protein at the lowest levels of zn (0,5 and 6 μM), but did not show the same dose dependent response as the activity. A decrease in the activity of PARP could, in part, be responsible for abnormalities of gene expression, cell division and growth seen during zn deficiency. (HA01743).
|Original language||English (US)|
|State||Published - 1997|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology