Probable lipid transporter that modulates cholesterol sequestration in the late endosome/lysosome by regulating the intracellular sphingolipid metabolism, in turn participates in cholesterol homeostasis (PubMed:17488728, PubMed:22748276). May alter the transbilayer distribution of ceramide in the intraluminal membrane lipid bilayer, favoring its retention in the outer leaflet that results in increased acid ceramidase activity in the late endosome/lysosome, facilitating ceramide deacylation to sphingosine leading to the sequestration of free cholesterol in lysosomes (By similarity). In addition regulates amyloid-beta production either by activating a signaling pathway that regulates amyloid precursor protein transcription through the modulation of sphingolipid metabolism or through its role in gamma-secretase processing of APP (PubMed:22086926). May play a role in myelin formation (PubMed:17060448). Forms discrete, punctate intracellular vesicles. Widely expressed in adult tissues. Highest levels are found in brain and pregnant uterus. Higly expressed in oligodendrocytes and weakly in the cerebral cortex. Highly expressed in some large pyramidal cells in layer V (PubMed:17488728). Methylated at Gln-271 by N6AMT1. Homozygote knockout mice for the ABCA2 gene are viable and fertile (PubMed:17488728, PubMed:17060448). Mice are born at the expected Mendelian ratio and exhibit a phenotype including lower pregnancy rate and body weight, shorter latency period on the balance beam, and sensitization to environmental stress compared with wild type mice (PubMed:17488728). Homozygote knockout males and females are viable and fertile. However, a non-Mendelian inheritance pattern is found among male progeny of heterozygous crosses. Mice display a tremor without ataxia, hyperactivity, and reduced body weight; the latter two phenotypes are more marked in females than in males (PubMed:17060448). Belongs to the ABC transporter superfamily. ABCA family.