Abstract
SPK1/RAD53/SAD1/MEC2 encodes an essential protein kinase of Saccharomyces cerevisiae and is required for the execution of checkpoint arrest at multiple stages of the cell cycle. We have isolated two mutant alleles of SPK1 (spk1K227A and spk1-1A208P) that are defective for checkpoint-arrest functions but retain wild-type levels of SPK1-associated growth activity. Both mutations occur within conserved regions of the kinase domain of SPK1 resulting in a substantial reduction in the catalytic activity of Spk1. Thus, while minimal levels of Spk1 kinase activity are capable of supporting normal rates of growth, higher levels are required for checkpoint functions. In addition, using deletional analysis we have identified a region within the N-terminus of Spk1 outside of the conserved kinase domain that is required for checkpoint functions. Interestingly, this region may be important in the regulation of Spk1 kinase activity.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 27 March 1996 / Accepted: 5 August 1996
Rights and permissions
About this article
Cite this article
Fay, D., Sun, Z. & Stern, D. Mutations in SPK1/RAD53 that specifically abolish checkpoint but not growth-related functions. Curr Genet 31, 97–105 (1997). https://doi.org/10.1007/s002940050181
Issue Date:
DOI: https://doi.org/10.1007/s002940050181