Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex (phycobilisome, PBS). Phycocyanin is the major phycobiliprotein in the PBS rod. Heterodimer of an alpha and a beta subunit, which further assembles into trimers (PubMed:12460674, PubMed:12615541). The trimers assemble into hexamers (Probable). Part of the phycobilisome rod. Contains one covalently linked phycocyanobilin chromophore. Belongs to the phycobiliprotein family.