| 17618627 |
Monreal JA, Feria AB, Vinardell JM, Vidal J, Echevarria C, Garcia-Maurino S: ABA modulates the degradation of phosphoenolpyruvate carboxylase kinase in sorghum leaves. FEBS Lett. 2007 Jul 24;581(18):3468-72. Epub 2007 Jun 29.
Salt stresses strongly enhance the phosphoenolpyruvate carboxylase kinase (PEPC-k) activity of sorghum leaves. This work shows that (1) abscisic acid (ABA) increased the rise in kinase activity in illuminated leaf disks of the non-stressed plant, (2) ABA decreased the disappearance of PEPC-k activity in the dark, (3) two PEPC-k genes expressed in sorghum leaves, PPCK1 and PPCK2, were not up-regulated by the phytohormone and, (4) ABA effects were mimicked by MG132, a powerful inhibitor of the ubiquitin-proteasome pathway. Collectively these data support a role for the ubiquitin-proteasome pathway in the rapid turnover of PEPC-k. The negative control by ABA on this pathway might account for the increase of kinase activity observed in salt-treated plants. |
2(0,0,0,2) |