Effects of protein kinase C activators and staurosporine on protein kinase activity, cell survival, and proliferation in Tetrahymena thermophila

E M Straarup, P Schousboe, H Q Hansen, Karsten Kristiansen, Else Kay Hoffmann, L Rasmussen, S. T. Christensen

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15 Citations (Scopus)

Abstract

Autocrine factors prevent cell death in the ciliate Tetrahymena thermophila, a unicellular eukaryote, in a chemically defined medium. At certain growth conditions these factors are released at a sufficient concentration by > 500 cells ml-1 to support cell survival and proliferation. The protein kinase C activators phorbol 12-myristate 13-acetate (PMA) or 1-oleyl 2-acetate glycerol (OAG) when added to 250 cells ml-1 supported cell survival and proliferation. In the presence of the serine and threonine kinase inhibitor staurosporine the cells died both at 250 cells ml-1 in cultures supplemented with either PMA or OAG, or at 2,500 cells ml-1. At 500 cells ml-1 PMA induced the in vivo phosphorylation of at least six proteins. The myelin basic protein fragment 4-14 was phosphorylated in vitro in crude extracts of a culture of 250,000 cells ml-1. Both the in vivo and the in vitro phosphorylation were inhibited by staurosporine.
Original languageEnglish
JournalMicrobios
Volume91
Issue number368-369
Pages (from-to)181-90
Number of pages9
ISSN0026-2633
Publication statusPublished - 1997
Externally publishedYes

Bibliographical note

Keywords: Animals; Autoradiography; Croton Oil; Diglycerides; Electrophoresis, Polyacrylamide Gel; Enzyme Activation; Enzyme Inhibitors; Myelin Basic Proteins; Phosphorylation; Protein Kinase C; Staurosporine; Tetradecanoylphorbol Acetate; Tetrahymena thermophila

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