We report here the isolation and sequence of a cDNA for the type II regulatory subunit of the cAMP-dependent protein kinase (cAMP-PK) from a λgt-11 cDNA library derived from a porcine epithelial cell line (LLC-PK 1). The cDNA was detected by immunological screening using an affinity purified polyclonal antibody for bovine R II. DNA sequence analysis of the 467 bp EcoRI insert confirmed the identity of the clone, because the deduced amino acid sequence corresponded to the published sequence for the bovine R Π protein. Northern analysis of total RNA from the LLC-PK 1 cells indicated a single mRNA species of about 6.0 kb, probably derived from a single copy gene.