Role of calmodulin-dependent phosphorylation of elongation factor 2 in the proliferation of rat glial cells.

Abstract

Calmodulin (CaM) is believed to play an important role in the regulation of cellular proliferation. The mechanism of regulation, although unknown, may involve CaM-binding proteins, particularly CaM-dependent protein kinases. Previously, we have shown that CaM-dependent protein kinase III phosphorylates elongation factor 2 (EF-2) in proliferating, C6 glioma cells but not in normal white matter, a tissue rich in nonproliferating glia. To determine whether CaM-dependent phosphorylation of EF-2 is linked, in general, to cellular division, we studied the phosphorylation of EF-2 in proliferating and growth-arrested C6 cells and in proliferating, primary cultures of normal glia. Phosphorylation of EF-2 was not detectable in C6 cells arrested in their growth by serum deprivation. When serum-deprived cells were stimulated to proliferate by the re-addition of serum, the amount of phosphorylated EF-2 correlated with levels of [3H]thymidine incorporation into DNA. Primary cultures of dividing, normal glia, obtained from neonatal rats, also demonstrated phosphorylation of EF-2. Therefore, the CaM-dependent phosphorylation of EF-2 appears to be associated with cellular proliferation in normal and malignant glia in the rat.

• Authors: D M Bagaglio, W N Hait
• Journal: Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research (Cell Growth Differ) Vol. 5 Issue 12 Pg. 1403-8 (Dec 1994) ISSN: 1044-9523 [Print] United States
• PMID: 7696190 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Calmodulin
• Glial Fibrillary Acidic Protein
• Peptide Elongation Factor 2
• Peptide Elongation Factors
• Egtazic Acid
• Eef2k protein, rat
• Calcium-Calmodulin-Dependent Protein Kinases
• Elongation Factor 2 Kinase
• Calcium
• Thymidine

Topics

• Animals
• Animals, Newborn
• Calcium (pharmacology)
• Calcium-Calmodulin-Dependent Protein Kinases (metabolism)
• Calmodulin (metabolism, pharmacology)
• Cell Division (drug effects)
• Cell Line
• Cells, Cultured
• Egtazic Acid (pharmacology)
• Elongation Factor 2 Kinase
• Glial Fibrillary Acidic Protein (analysis)
• Glioma
• Neuroglia (cytology, drug effects, metabolism)
• Peptide Elongation Factor 2
• Peptide Elongation Factors (isolation & purification, metabolism)
• Phosphorylation
• Prosencephalon (cytology, metabolism)
• Rats
• Thymidine (metabolism)
• Tumor Cells, Cultured