Regulatory subunit of the cAMP-dependent protein kinases involved in cAMP signaling in cells. Type II regulatory chains mediate membrane association by binding to anchoring proteins, including the MAP2 kinase. Belongs to the cAMP-dependent kinase regulatory chain family. Four types of regulatory chains are found: I-alpha, I-beta, II-alpha, and II-beta. Their expression varies among tissues and is in some cases constitutive and in others inducible. 2 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.