ISSN:
1432-2048
Keywords:
Key words:Catharanthus (transformed)
;
Protein phos-phorylation
;
Signal transduction
;
Tyrosine kinase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract. Homogenate fractions (soluble and particulate) from transformed roots of Catharanthus roseus (L.) G. Don showed several phosphorylated proteins when incubated with γ-[32P]ATP. The phosphorylation in the proteins of 55, 40, 25, 18 and 10 kDa in the particulate fraction and 63 kDa in the soluble fraction was resistant to alkali treatment. Several proteins in both fractions gave a positive signal with monoclonal antiphosphotyrosine antibodies. In-situ phosphorylation in both fractions showed several proteins that cross-reacted with the antiphosphotyrosine antibodies. Tyrosine kinase activity was detected using an exogenous substrate RR-SRC, a synthetic peptide derived from the amino acid sequence surrounding the phosphorylation site in pp60src. This activity was inhibited by genistein, a tyrosine kinase inhibitor. These results indicate, for the first time, the presence of protein-tyrosine kinase (EC 2.7.1.112) activity in transformed plant tissues.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004250050231
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