tailieunhanh - Báo cáo khoa học: Regulation of calpain B from Drosophila melanogaster by phosphorylation

Calpain B is one of the two catalytically competent calpain (calcium-acti-vated papain) isoenzymes in Drosophila melanogaster. Because structural predictions hinted at the presence of several potential phosphorylation sites in this enzyme, we investigated the in vitro phosphorylation of the recombi-nant protein by protein kinase A as well as by the extracellular signal-regu-lated protein kinases (ERK) 1 and 2. | ỊFEBS Journal Regulation of calpain B from Drosophila melanogaster by phosphorylation 1 3 1 2 2 László Kovacs Anita Alexa Eva Klement Endre Kokai Agnes Tantos Gergo Gogl Tamas Sperka4 Katalin F. Medzihradszky3 5 Jozsef Tozser4 Viktor Dombradi1 6 and Peter Friedrich2 1 Department of MedicalChemistry Faculty of Medicine University of Debrecen Hungary 2 Institute of Enzymology BiologicalResearch Center Hungarian Academy of Sciences Budapest Hungary 3 Proteomics Research Group BiologicalResearch Center Hungarian Academy of Sciences Szeged Hungary 4 Department of Biochemistry and Molecular Biology Faculty of Medicine University of Debrecen Hungary 5 Department of PharmaceuticalChemistry University of California at San Francisco CA USA 6 HAS-DU CellBiology and Signaling Research Group Department of MedicalChemistry Research Center for Molecular Medicine University of Debrecen Hungary Keywords calcium-dependent protease Drosophila melanogaster enzyme kinetics epidermal growth factor protein kinase Correspondence V. Dombradi Department of Medical Chemistry Faculty of Medicine University of Debrecen 98 Nagyerdei krt Debrecen H-4032 Hungary Fax 36 52 412 566 Tel 36 52 412 345 E-mail dombradi@ These authors contributed equally to this work Received 23 April2008 revised 15 June 2009 accepted 6 July 2009 doi Calpain B is one of the two catalytically competent calpain calcium-activated papain isoenzymes in Drosophila melanogaster. Because structural predictions hinted at the presence of several potential phosphorylation sites in this enzyme we investigated the in vitro phosphorylation of the recombinant protein by protein kinase A as well as by the extracellular signal-regulated protein kinases ERK 1 and 2. By MS we identified Ser845 in the Ca2 binding region of an EF-hand motif and Ser240 close to the autocatalytic activation site of calpain B as being the residues phosphorylated by protein kinase A. In the transducer region of the