Functional conservation between the human, nematode, and yeast CK2 cell cycle genes

Protein kinase CK2 (formerly casein kinase II) is a highly conserved serine /threonine protein kinase ubiquitous in eukaryotic organisms. Previously, w e have shown that CK2 is required for cell cycle progression and essential for the viability of the yeast Saccharomyces cerevisiae. We now report that either the human or the nematode Caenorhabditis elegans CK2 alpha catalyti c subunit can substitute for the yeast catalytic subunits. Additionally, ex pression of the human CK2 regulatory subunit (CK2 beta) can suppress the te mperature sensitivity of either of the two yeast CK2 mutant catalytic subun its. Taken together, these observations reinforce the view that the CK2 cel l cycle progression genes have been highly conserved during evolution from yeast to humans, not only in structure but also in function. (C) 2001 Acade mic Press.