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DNA binding activity of casein kinase II
O Filhol1, C Cochet, E M Chambaz
1Unité INSERM 244, DBMS/BRCE, Centre d'Etudes Nucléaires, Grenoble, France.
Biochemical and Biophysical Research Communications
|December 31, 1990
Summary
Casein kinase II (CKII), a protein kinase, binds to genomic DNA in vitro. This interaction may play a role in how cells respond to growth factors and proliferate.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Casein kinase II (CKII) is a ubiquitous, oligomeric, messenger-independent protein kinase.
- CKII concentrates in the nucleus during cell proliferation.
Purpose of the Study:
- To investigate the interaction between purified mammalian CKII and genomic DNA in vitro.
- To elucidate the role of CKII-DNA interaction in cellular signaling pathways.
Main Methods:
- In vitro binding assays using purified mammalian CKII and genomic DNA preparations.
- Characterization of binding kinetics and affinity (Kd).
- Blotting experiments to identify the CKII subunit involved in DNA binding.
Main Results:
- Purified mammalian CKII interacts with genomic DNA in vitro, with optimal binding to double-stranded DNA.
- High-affinity binding sites were identified on lambda phage DNA (Kd ≈ 6 x 10(-13) M).
- CKII-DNA interaction was enhanced by polyamines and inhibited by heparin, with the alpha subunit mediating binding.
Conclusions:
- CKII binds to genomic DNA, potentially influencing its kinase activity by preventing aggregation.
- The alpha subunit of CKII is responsible for DNA binding.
- CKII may function as a component in signal transduction, relaying mitogenic signals from the cell membrane to the nucleus in response to growth factors.