. "Modulates the activity of a cyclin-dependent protein kinase, enzymes of the protein kinase family that are regulated through association with cyclins and other proteins." . . "cyclin" . "G1/S-specific cyclin" . "cyclin-dependent protein kinase regulator activity" . "cyclin-dependent protein kinase, intrinsic regulator activity" . "G2/M-specific cyclin" . . . . . . .