The role of workhorse protein kinases in coordinating DNA metabolism and cell growth.

Cells are continually experiencing various forms of DNA damage. External factors such as environmental agents and radiation or internal factors such as oxidative damage or replication errors can all lead to potentially mutagenic or lethal DNA lesions. UV irradiation and DNA strand interruptions, for example, stimulate transcription and genetic recombination, lead to the activation of DNA repair proteins, cause cell cycle arrest, and initiate nuclear signal transduction cascades (Hartwell 1992; Hartwell and Weinart 1989; Hibi et al. 1993).