Regulatory subunit of the cAMP-dependent protein kinases involved in cAMP signaling in cells. The inactive holoenzyme is composed of two regulatory chains and two catalytic chains. Activation by cAMP releases the two active catalytic monomers and the regulatory dimer. Interacts with PRKX; regulates this cAMP-dependent protein kinase. 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. Belongs to the cAMP-dependent kinase regulatory chain family. Note: This description may include information from UniProtKB.
Protein type: Protein kinase, regulatory subunit
Cellular Component: plasma membrane; cytosol; cAMP-dependent protein kinase complex
Molecular Function: cAMP-dependent protein kinase inhibitor activity; cAMP-dependent protein kinase regulator activity; cAMP binding
Biological Process: epidermal growth factor receptor signaling pathway; fibroblast growth factor receptor signaling pathway; nerve growth factor receptor signaling pathway; water transport; activation of protein kinase A; signal transduction; protein amino acid phosphorylation; learning and/or memory; phospholipase C activation; energy reserve metabolic process; innate immune response; blood coagulation; transmembrane transport; regulation of insulin secretion
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.