Phosphorylation of ribosomal protein S6 and its regulation during differentiation of human leukemic cells
Journal of Korean Medical Science
;
: 413-419, 1993.
Article
Dans Anglais
| WPRIM
| ID: wpr-89027
ABSTRACT
We attempted to study the role of protein tyrosine kinase (PTK) and protein kinase C (PKC) in the cascade of phosphorylation of ribosomal protein S6 during differentiation of leukemic cells (HL-60, THP-1, and RWLeu-4). Neither activation nor inhibition of colony stimulating factor-1 (CSF-1) receptor's PTK activity with CSF-1 or genistein respectively affected the phosphorylation of S6. However, vanadate which is a protein tyrosine phosphatase (PTP) inhibitor showed enhancement of S6 phosphorylation. Dimethylsulfoxide which does not affect either PTK or PKC demonstrated no change in S6 phosphorylation. PKC activation by acute 12-0-tetradecanoyl phorbol-13-acetate (TPA) treatment induced monocytic differentiation and S6 phosphorylation. Surprisingly, the more prominent phosphorylation of S6 protein was observed in PKC-depleted cells by prolonged TPA treatment. Our results suggest that PTK/PTP play a lesser role in S6 phosphorylation of HL-60 cells than PKC does. In addition, two different mechanisms seem to be involved in TPA-induced S6 phosphorylation during HL-60 differentiation PKC activation by acute TPA treatment and PKC depletion which may lead to the synthesis of some endogenous protein responsible for the differentiation by chronic TPA treatment.
Texte intégral:
Disponible
Indice:
WPRIM (Pacifique occidental)
Sujet Principal:
Phosphorylation
/
Protéines ribosomiques
/
Protéine kinase C
/
Protein-tyrosine kinases
/
12-Myristate-13-acétate de phorbol
/
Cellules cancéreuses en culture
/
Leucémies
/
Différenciation cellulaire
/
Facteur de stimulation des colonies de macrophages
/
Protéine ribosomique S6
Limites du sujet:
Humains
langue:
Anglais
Texte intégral:
Journal of Korean Medical Science
Année:
1993
Type:
Article
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