POLDIP3 (polymerase delta-interacting protein 3), also known as SKAR or PDIP46, is a 421 amino acid nuclear protein. POLDIP3 interacts with DNA pol ∂ 2, a protein essential to DNA replication, recombination and repair. POLDIP3 is a substrate for the signaling intermediate Rsk-1 and is thought to regulate cell growth. POLDIP3 contains one RRM (RNA recognition motif) domain and is phosphorylated upon DNA damage. POLDIP3 is ubiquitously expressed with highest levels found in heart, kidney, skeletal muscle and brain. Due to alternative splicing, POLDIP3 is expressed as two isoforms.