cAMP-dependent Protein Kinase Is Necessary for Increased NF-E2DNA Complex Formation during Erythroleukemia Cell Differentiation

• Published in: The Journal of biological chemistry Vol. 270; no. 16; pp. 9169 - 9177
• Main Authors: Garingo, A D, Suhasini, M, Andrews, N C, Pilz, R B
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 21.04.1995
• Subjects: Base Sequence; Cell Differentiation; Cyclic AMP-Dependent Protein Kinases - physiology; DNA - metabolism; DNA-Binding Proteins - metabolism; Enhancer Elements, Genetic; Erythroid-Specific DNA-Binding Factors; Leukemia, Erythroblastic, Acute - metabolism; Leukemia, Erythroblastic, Acute - pathology; Molecular Sequence Data; NF-E2 Transcription Factor; NF-E2 Transcription Factor, p45 Subunit; Phosphorylation; Promoter Regions, Genetic; Transcription Factors - metabolism; Transfection; Tumor Cells, Cultured
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.270.16.9169

When murine erythroleukemia (MEL) cells are induced to differentiate by hexamethylene bisacetamide (HMBA), erythroid-specific genes are transcriptionally activated; however, transcriptional activation of these genes is severely impaired in cAMP-dependent protein kinase (protein kinase A)-deficient MEL cells. The transcription factor NF-E2, composed of a 45-kDa (p45) and an 18-kDa (p18) subunit, is essential for enhancer activity of the globin locus control regions (LCRs). DNA binding of NF-E2 and α-globin LCR enhancer activity was significantly less in HMBA-treated protein kinase A-deficient cells compared to cells containing normal protein kinase A activity; DNA binding of several other transcription factors was the same in both cell types. In parental cells, HMBA treatment and/or prolonged activation of protein kinase A increased the amount of NF-E2 DNA complexes without change in DNA binding affinity; the expression of p45 and p18 was the same under all conditions. p45 and p18 were phosphorylated by protein kinase A in vitro , but the phosphorylation did not affect NF-E2 DNA complexes, suggesting that protein kinase A regulates NF-E2 DNA complex formation indirectly, e.g. by altering expression of a regulatory factor(s). Thus, protein kinase A appears to be necessary for increased NF-E2 DNA complex formation during differentiation of MEL cells and may influence erythroid-specific gene expression through this mechanism.