Protein Kinase C and Casein Kinase 2 Phosphorylate in vitro Proteins of the Annexin Family from Eggs of Loach Misgurnus fossilis

A. A. Minin^1*, E. A. Zemskov¹, and N. V. Khaidarova²

¹Kol’tsov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 117808 Russia; fax: (095) 135-8012; E-mail: minin@ibrran.msk.su

²Institute of Molecular Genetics, Russian Academy of Sciences, pl. Kurchatova 46, Moscow, 123182 Russia

^* To whom correspondence should be addressed.

Received January 28, 1998; Revision received May 28, 1998

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A mixture of proteins of the annexin family was obtained from the cytoplasm of mature eggs of loach Misgurnus fossilis (by reprecipitation with acid phospholipids in the presence of Ca²⁺). This mixture comprised five proteins with molecular weights of 58, 38, 36, 35, and 31 kD. Polyclonal rabbit antibodies against the major 31-kD protein were obtained. Western blot analysis showed that the obtained antibodies exhibit a high specificity towards the 31-kD protein from eggs and other tissues of loach and zebrafish (Brachydanio rerio). The analysis of cDNA corresponding to the 31-kD protein by screening the zebrafish cDNA library confirmed that this protein belongs to the annexin family. Phosphorylation of the obtained annexins in vitro was studied. It is shown that the 58-kD protein is phosphorylated by casein kinase 2 (CK2), whereas the 38-, 36-, 35-, and 31-kD proteins are phosphorylated by protein kinase C (PKC).

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KEY WORDS: annexin, protein kinase C, casein kinase 2, Misgurnus fossilis, Brachydanio rerio

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