"the third subunit of human DNA polymerase delta, p66, interacts with PCNA through a canonical PCNA-binding sequence located in its C terminus"

"Reconstitution and characterization of the human DNA polymerase delta four-subunit holoenzyme."

"Identification of a novel protein, PDIP38, that interacts with the p50 subunit of DNA polymerase delta and proliferating cell nuclear antigen."

"the purified human WRNIP1 complex interacted physically with human DNA polymerase delta (pol delta), stimulating its DNA synthesis activity more than fivefold in the presence or absence of proliferating cell nuclear antigen"

"we have mapped the interaction domains for binding to the p50 polymerase delta subunit and with PCNA to the N-terminus and the C-terminus of p66"

"which is tightly associated with the p50 subunit"

"This study examines the role of the p12 subunit in the function of the human DNA polymerase δ (Pol δ) holoenzyme by comparing the kinetics of DNA synthesis and degradation catalyzed by the four subunit complex"

"( i ) the B-subunit of Pol δ binds equally well to the catalytic subunit of either Pol δ or Pol ζ; ( ii ) the CTDs of Pol δ and Pol ζ contain a [4Fe-4S] cluster, which is critical for binding to the B-subunit and for UV light-induced mutagenesis"

"we propose that Pol switches at replication-blocking lesions occur by the exchange of the Pol δ and Pol ζ catalytic subunits on a preassembled complex of accessory proteins retained on DNA during translesion DNA synthesis."

"The purified four-subunit Pol ζ4 (Rev3–Rev7–PolD2–PolD3) is much more efficient and more processive at bypassing a 1,2-intrastrand d(GpG)-cisplatin cross-link than the two-subunit Pol ζ2 (Rev3–Rev7)."

"The cocrystal structure of human PolD2 and the NTD of PolD3 has been determined ( 35 ) and shows a primarily negatively charged molecular surface without obvious features for DNA binding."

"Only POLD2, the B-subunit of Polδ, was found to bind to Polη in a two-hybrid experiment and this interaction was further confirmed in a pull-down assay. Mutation of the FF483–484 motif of Polη (designated F1 motif) involved in the interaction with POLD2 reduces the Polη ability to perform TLS catalyzed by cellular extracts in vitro and to rescue the UV sensitivity of XPV fibroblasts."

"The mammalian polymerase δ complex is a heterotetramer consisting of the catalytic subunit POLD1 and the accessory subunits POLD2, POLD3, and POLD4"

"The specific function of the POLD2 subunit has been poorly explored, despite its central structural role in interacting with both POLD1 and POLD3 ( 12 ). Interestingly, POLD2 and POLD3 participate in translesion synthesis (TLS) via their interaction with the polymerase ζ complex"

"In patients from 2 independent pedigrees, we have identified what we believe to be a novel syndrome with reduced functionality of the polymerase δ complex caused by germline biallelic mutations in POLD1 or POLD2 as the underlying etiology of a previously unknown autosomal-recessive syndrome that combines replicative stress, neurodevelopmental abnormalities, and immunodeficiency."

"More recently, it was revealed that human Pol ζ can contain 2 subunits in addition to REV3 and REV7, and this holoenzyme is referred to as Pol ζ444. These two additional subunits are POLD2 and POLD3, both of which are also subunits of human Pol δ."

"Key proteins involved in the BER pathway, including APEX1/2, XRCC1, PARP1, POLD2, have been associated with chemoresistance across many cancer types."

"Biallelic mutations in POLD1 or POLD2 are also found in patients manifesting an autosomal recessive syndrome that combines replicative stress, neurodevelopmental abnormalities and immunodeficiency. Homozygous missense variant D293N was found in the POLD2 gene."

"The interaction between POLD3 and POLD2 is essential for normal Polδ function — mutations of the POLD2-POLD3 interaction region in S. cerevisiae cause the cdc27 cold sensitive phenotype. We speculate that modulation of POLD1 catalytic activity by POLD3 may be by influencing POLD2-POLD1 interactions, centered at CysA and CysB motifs of POLD1."

"Human Polδ holoenzyme has been believed to be a heterotetramer in unstressed, non-dividing cells composed of a catalytic subunit (POLD1) and three accessory subunits, POLD2 (p50), POLD3 (p66/p68), and POLD4 (p12)"

"cDNAs encoding the small subunit of bovine and human DNA polymerase delta have been cloned and sequenced. The predicted polypeptides, 50,885 and 51,289 Daltons, respectively, are 94% identical"

"POLD2 functions as an **essential non-catalytic subunit** of the Polδ holoenzyme, supporting assembly, stability, and productive interactions among subunits required for high-fidelity DNA synthesis in nuclear DNA replication and repair-associated synthesis."

"POLD2 is relevant because it is part of Polδ and is also shared with **Polζ4** (a translesion polymerase complex), supporting polymerase switching and stress-tolerant DNA synthesis."