ATAD3A is an essential mitochondrial membrane protein that serves multiple critical functions in mitochondrial homeostasis and cellular stress responses. The protein plays a fundamental role in mitochondrial network organization, metabolism, and cell growth 1. ATAD3A regulates mitophagy by interacting with PINK1 and controlling its stability - specifically, it mediates mitochondrial import and degradation of PINK1, with AMBRA1 promoting PINK1 stability by counteracting ATAD3A's degradative effects 2. During endoplasmic reticulum stress, ATAD3A provides crucial protection for mitochondrial protein synthesis by directly interacting with PERK at mitochondria-ER contact sites, inhibiting PERK activity independently of its ATPase function 1. The protein also participates in innate immune responses, as mutations in ATAD3A trigger enhanced cGAS-STING-dependent interferon signaling through mitochondrial DNA release 3. Additionally, ATAD3A regulates cellular senescence through TBK1-mediated phosphorylation at Ser321, which suppresses Pink1-mediated mitophagy 4. Clinically, ATAD3A mutations cause distinct neurological syndromes including global developmental delay, hypotonia, optic atrophy, and cardiomyopathy, with the recurrent p.Arg528Trp variant functioning through a dominant-negative mechanism that reduces mitochondrial content 5. The protein also influences cancer therapy resistance by regulating PD-L1 subcellular localization 6.