Polymerase Delta Interacting Protein 3 (POLdIP3)

POLDIP3 encodes a protein that interacts with the DNA polymerase delta p50 subunit. This protein is a specific target of S6 kinase 1 and regulates cell growth. Two transcript variants that encode different protein isoforms have been identified.The encoded protein contains a C-terminal RNA recognition motif (RRM) with highest homology to the ALY (THOC4)/REF family of RNA-binding proteins. They identified a SKAR-alpha isoform of 421 amino acids with a predicted molecular mass of 46 kD and a SKAR-beta isoform of 392 amino acids with a predicted molecular mass of 43 kD. Northern blot analysis of human tissues detected ubiquitous expression with highest levels in brain, heart, skeletal muscle, and kidney. Immunofluorescence microscopy showed nuclear localization both in nucleoplasm and in punctate structures.