We have cloned genes for two closely related protein kinase (PK) homol
ogues from Saccharomyces cerevisiae. Sequence alignment of the kinase
domain with previously characterized PK reveals the highest degree of
similarity with second messenger-regulated kinases. RCK1 encodes a 58-
kDa protein, and is weakly expressed. RCK2 encodes a 65-kDa protein, a
nd transcripts from this gene are readily detected. RCK1 has been mapp
ed to the L arm of chromosome VII, and RCK2 to chromosome XII. Disrupt
ion of these genes in the S. cerevisiae genome demonstrates that both
genes are non-essential.