The effect of spermine on calcium requirement for protein kinase C association with phospholipid vesicles
| Autor: | Gaetano Marverti, Chiara Frassineti, Giorgio Piccinini, Maria Stella Moruzzi, Maria Giuseppina Monti |
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| Rok vydání: | 1995 |
| Předmět: |
PRKCQ
polyamines Spermine Biology Biochemistry Radioligand Assay chemistry.chemical_compound phospholipid vesicles Ca2+/calmodulin-dependent protein kinase Animals protein kinase C Protein kinase A Phorbol 12 13-Dibutyrate Phospholipids Protein Kinase C Protein kinase C PTK2B Cell Membrane Cell Biology Rats chemistry Cyclin-dependent kinase complex Calcium cGMP-dependent protein kinase |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 1357-2725 |
| DOI: | 10.1016/1357-2725(95)00054-s |
| Popis: | We have previously reported that polyamines interfere with protein kinase C-membrane interactions. With the aim of clarifying the influence of the relationship between calcium and polyamines on this process we have investigated the effect of spermine on the formation of active protein kinase C-membrane complexes as a function of Ca++ concentrations. Protein kinase C, purified from rat brain, was allowed to interact with phospholipid vesicles of defined composition. The active complex protein kinase C-liposomes was determined by its ability to bind radioactive phorbol ester with an exact 1:1 stoichiometry. The results show that, at Ca++ levels below 0.1 μM, spermine inhibits the formation of complexes between protein kinase C and membranes. At higher Ca++ concentrations, spermine does not prevent the association process but does influence the ratio between the enzyme molecules irreversibly inserted into the membrane and those reversibly associated with it. We have also demonstrated that spermine, by reducing the density of acidic component of liposomes, influences the calcium requirement for protein kinase C-membrane binding. This study indicates that spermine may regulate the activation of protein kinase C and affects the calcium requirement for the association of this enzyme with the phospholipid bilayer. The results suggest a possible role for polyamines in signal transduction when protein kinase C is involved. |
| Databáze: | OpenAIRE |
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