Involvement of G‐proteins in chitosan‐induced Anthraquinone synthesis in Rubia tinctorum

• DOI: 10.1111/j.1399-3054.2006.00717.x
• Publication Date: 2006-07-08T00:04:56Z
• Authors: Andrea Vasconsuelo; Gabriela Picotto; Ana M. Giuletti; Ricardo Boland
• Keywords: Anthraquinones

We have previously shown that chitosan stimulates anthraquinone synthesis in Rubia tinctorum L. cells through activation of the PLC\PKC, PI3K, MAPK and Ca 2+ messenger systems. In view this evidence, we now investigated whether guanine nucleotide‐binding G‐proteins are part signal transduction mechanism which mediates elicitor action. The G‐protein agonists mastoparan, AlF 4 – GTPyS increased levels to same extent as chitosan. No additive effects were observed when cultured R. treated with agonist together. agreement these observations, antagonists suramin GDPβS abolished increase induced by Furthermore, elicitation was not affected presence pertussis toxin. Consistent result, cell cultures preincubated a monoclonal anti‐Gαq\11 antibody, chitosan‐dependent fully inhibited. Moreover, an immunoreactive protein expected size for Gαq\11 (42 kDa) microsomal membranes Western blot analysis using antibody. These results indicate heterotrimeric G‐protein, most likely belonging Gαq family.