tailieunhanh - Báo cáo khoa học: S-nitrosylated proteins of a medicinal CAM plant Kalanchoe pinnata – ribulose-1,5-bisphosphate carboxylase⁄oxygenase activity targeted for inhibition

Nitric oxide (NO) is a signaling molecule that affects a myriad of processes in plants. However, the mechanistic details are limited. NO post-transla-tionally modifies proteins by S-nitrosylation of cysteines. The soluble S-nitrosoproteome of a medicinal, crassulacean acid metabolism (CAM) plant,Kalanchoe pinnata, was purified using the biotin switch technique. | ễFEBS Journal S-nitrosylated proteins of a medicinal CAM plant Kalanchoe pinnata - ribulose-1 5-bisphosphate carboxylase oxygenase activity targeted for inhibition Jasmeet K. Abat1 Autar K. Mattoo2 and Renu Deswal1 1 Department of Botany Plant Molecular Physiology and Biochemistry Laboratory University of Delhi India 2 Sustainable AgriculturalSystems Laboratory The Henry A. Wallace Beltsville AgriculturalResearch Center MD USA Keywords biotin switch technique Kalanchoe pinnata nitric oxide Rubisco S-nitrosylation Correspondence R. Deswal Department of Botany Plant Molecular Physiology and Biochemistry Laboratory University of Delhi Delhi 110007 India Fax Tel 91 11 27662273 E-mail rdeswal@ Received 12 January 2008 revised 12 March 2008 accepted 31 March 2008 doi Nitric oxide NO is a signaling molecule that affects a myriad of processes in plants. However the mechanistic details are limited. NO post-transla-tionally modifies proteins by S-nitrosylation of cysteines. The soluble S-nitrosoproteome of a medicinal crassulacean acid metabolism CAM plant Kalanchoe pinnata was purified using the biotin switch technique. Nineteen targets were identified by MALDI-TOF mass spectrometry including proteins associated with carbon nitrogen and sulfur metabolism the cytoskeleton stress and photosynthesis. Some were similar to those previously identified in Arabidopsis thaliana but kinesin-like protein glycolate oxidase putative UDP glucose 4-epimerase and putative DNA topoisomerase II had not been identified as targets previously for any organism. In vitro and in vivo nitrosylation of ribulose-1 5-bisphosphate carboxylase oxygenase Rubisco one of the targets was confirmed by immunoblotting. Rubisco plays a central role in photosynthesis and the effect of S-nitrosy-lation on its enzymatic activity was determined using NaH14CO3. The NO-releasing compound S-nitrosoglutathione inhibited its activity in a dose-dependent manner suggesting .