Effect of Brassinolide on Tyrosine Phosphorylation of Pea Leaf Proteins

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E. O. Fedina^*, F. G. Karimova, and I. A. Tarchevsky

Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center, Russian Academy of Sciences, ul. Lobachevskogo 2/31, 420111 Kazan, Russia; fax: (7-843) 292-7347; E-mail: fedina@mail.knc.ru

^* To whom correspondence should be addressed.

Received June 20, 2005; Revision received September 29, 2005

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Brassinosteroid-induced phosphorylation of tyrosine residues in proteins was studied. Proteins of crude extract of pea leaves were analyzed by one- and two-dimensional electrophoresis followed by Western blotting with monoclonal antibodies PY20 to phosphotyrosine proteins. One- and two-dimensional electrophoresis revealed 7 and 13 tyrosine-phosphorylated proteins, respectively. Brassinolide increased the phosphorylation level of most of these proteins. With inhibitors of tyrosine protein phosphatases, such as phenylarsine oxide and orthovanadate, the level of tyrosine phosphorylation of these proteins increased.

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KEY WORDS: brassinolide, tyrosine phosphorylation of proteins, Pisum sativum, tyrosine protein phosphatases, tyrosine protein kinases

DOI: 10.1134/S0006297906040109

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