CGK1, or Protein kinase, cGMP-dependent, type I, is a human gene encoded by PRKG1. It may also be known as: cGMP-dependent protein kinase 1; cGK1; cGMP-dependent protein kinase I; cGKI; cGK 1; AAT8; PKG; PRKG1B; PRKGR1B; cGK; cGKI-BETA; cGKI-alpha. The encoded protein is an enzyme with an amino acid length of 671 and a mass of 76.4 kDa. Other isoforms may exist. CGK1 is a member of the Protein kinase superfamily, AGC Ser/Thr protein kinase family, cGMP subfamily. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.