Leukoregulin-induced translocation of protein kinase C activity in K562 cells.

Abstract

Leukoregulin's effect on biochemical pathways involving Ca2+ was assessed in K562 erythroleukemia cells in which the antitumor lymphokine induces a rapidly reversible increase in plasma membrane permeability. Leukoregulin exposure activates protein kinase C but does not alter levels of phosphoinositol metabolites, calmodulin or cAMP. The activation pattern of protein kinase C differs from that induced by phorbol myristic acid (PMA), a potent activator of protein kinase C. PMA-induced translocation of protein kinase C from the cytosol to the plasma membrane is maximal by 2 min after addition of PMA whereas after leukoregulin treatment protein kinase C translocation reaches a maximum at 2 h. This suggests that leukoregulin activates protein kinase C via a non-classical phosphoinositol pathway as opposed to direct binding to protein kinase C as occurs with PMA. The temporal kinetics of the protein kinase C translocation and the increase in membrane permeability induced by leukoregulin are similar suggesting that phosphorylation of a membrane protein may be involved in the target cell destabilization of the plasma membrane by this lymphokine.

• Authors: S C Barnett, C H Evans
• Journal: Clinical and experimental immunology (Clin Exp Immunol) Vol. 73 Issue 3 Pg. 505-9 (Sep 1988) ISSN: 0009-9104 [Print] England
• PMID: 2850124 (Publication Type: Journal Article)

Chemical References

• Antineoplastic Agents
• Calmodulin
• Lymphokines
• Phosphatidylinositols
• leukoregulin
• Cyclic AMP
• Protein Kinase C

Topics

• Antineoplastic Agents (pharmacology)
• Calmodulin (metabolism)
• Cyclic AMP (metabolism)
• Humans
• Leukemia, Erythroblastic, Acute (enzymology)
• Lymphokines (pharmacology)
• Phosphatidylinositols (metabolism)
• Protein Kinase C (metabolism)
• Tumor Cells, Cultured (drug effects, metabolism)