Involved in GBF1 recruitment, Golgi maintenance and protein secretion. Interacts with PI4KB (PubMed:23572552). Interacts with GBF1 (PubMed:31519766). The majority of ARMD3 is cytosolic, with a portion colocalizing with GBF1 at juxtanuclear Golgi sites. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the ARMH3 family.