5'->3' DNA exonuclease which digests single-stranded DNA (ssDNA) (PubMed:30312375). Regulates inflammatory cytokine responses via the degradation of nucleic acids, by reducing the concentration of ssDNA able to stimulate TLR9, a nucleotide-sensing receptor in collaboration with PLD4 (By similarity). May be important in myotube formation (PubMed:22428023). Plays a role in lysosomal homeostasis (PubMed:28128235). Involved in the regulation of endosomal protein sorting (PubMed:29368044). Exonucleolytic cleavage in the 5'- to 3'-direction to yield nucleoside 3'-phosphates. Interacts with APP. Localizes to ER-associated vesicles in differentiating myotubes (PubMed:22428023). The soluble form in lysosome arises by proteolytic processing of the membrane-bound form (PubMed:29386126). Colocalizes with APP in endosomes (PubMed:29368044). Widely expressed. In the brain, high levels of expression are detected in the frontal, temporal and occipital cortices and hippocampus. Expressed at low level in corpus callosum. N-glycosylated. Proteolytically processed to a soluble form that is stable within endosomes and lysosomes. During transport through the secretory pathway becomes proteolysed by cysteine proteases, thereby releasing a stable soluble lysosomal lumenal polypeptide, whereas the transmembrane-bound fragment is rapidly degraded. Its transport route to lysosomes involves ubiquitination and the ESCRT complex. Ubiquitinated at N-terminus. Ubiquitination mediates sorting into lysosomes. The disease may be caused by variants affecting the gene represented in this entry. There is limited evidences for implication of PLD3 in SCA46. Knockout mice do not present signs of cerebellar degeneration or spinocerebellar ataxia at 9 months of age, challenging the interpretation of the suggested loss-of-function mechanism for PLD3 as the SCA46-causative gene. Genetic variants in PLD3 have been suggested to be associated with an increased risk for Alzheimer disease (PubMed:24336208, PubMed:25832409). Further studies, however, did not support PLD3 involvement in this disease (PubMed:25832408, PubMed:25832411, PubMed:25832413, PubMed:25832410, PubMed:26411346). Futhermore, it is controversial whether PLD3 plays a role in amyloid precursor protein processing (APP) or not (PubMed:24336208). In a relevant Alzheimer's disease mouse model PLD3 deficiency does not affect APP metabolism or amyloid plaque burden (PubMed:28128235). However one study shown that PLD3 influences APP processing (PubMed:24336208). Belongs to the phospholipase D family. It was initially thought that PDL3 has phospholipase D activity due to its HKD motifs. The second HKD motif contains Glu instead of the canonical Asp. Its enzyme activity is therefore unsure. Catalytic phospholipase D activity is still controversial (PubMed:29053796, PubMed:30312375). Its closest homolog PLD4, exhibits no phospholipase activity (By similarity).