This gene encodes a member of the serine/threonine protein kinase family. The holoenzyme, protein kinase A (also known as cyclic-AMP dependent protein kinase), mediates cellular response to changes in cyclic-AMP levels. This gene encodes the alpha catalytic subunit of protein kinase A. Protein kinase A-mediated signaling is transduced via phosphorylation of target proteins, and is important for many cellular functions, including mammalian sperm maturation and motility. Alternative splicing results in multiple transcript variants. A pseudogene of this gene has been defined on the X chromosome. [provided by RefSeq, Apr 2013]