Apolipoprotein D is a protein that in humans is encoded by the APODgene.[1][2][3] Unlike other lipoproteins, which are mainly produced in the liver, apolipoprotein D is mainly produced in the brain and testes.[4]
Apolipoprotein D (Apo-D) is a component of high-density lipoprotein that has no marked similarity to other apolipoprotein sequences. It has a high degree of homology to plasma retinol-binding protein and other members of the alpha 2 microglobulin protein superfamily of carrier proteins, also known as lipocalins. It is a glycoprotein of estimated molecular weight 33 KDa. Apo-D is closely associated with the enzyme lecithin:cholesterol acyltransferase - an enzyme involved in lipoprotein metabolism.[3] ApoD has also been shown to be an important link in the transient interaction between HDL and LDL particles and between HDL particles and cells.[5]
Clinical significance
APOD is a biomarker of androgen insensitivity syndrome (AIS). APOD is an androgen up-regulated gene in normal scrotal fibroblast cells in comparison to CAIS labia majora cells.[6]
↑Appari M, Werner R, Wünsch L, Cario G, Demeter J, Hiort O, Riepe F, Brooks JD, Holterhus PM (June 2009). "Apolipoprotein D (APOD) is a putative biomarker of androgen receptor function in androgen insensitivity syndrome". J. Mol. Med. 87 (6): 623–32. doi:10.1007/s00109-009-0462-3. PMID19330472.
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Holzfeind P, Merschak P, Dieplinger H, Redl B (1996). "The human lacrimal gland synthesizes apolipoprotein D mRNA in addition to tear prealbumin mRNA, both species encoding members of the lipocalin superfamily". Exp. Eye Res. 61 (4): 495–500. doi:10.1016/S0014-4835(05)80145-9. PMID8549691.
Cargill M, Altshuler D, Ireland J, et al. (1999). "Characterization of single-nucleotide polymorphisms in coding regions of human genes". Nat. Genet. 22 (3): 231–8. doi:10.1038/10290. PMID10391209.
Liu Z, Chang GQ, Leibowitz SF (2001). "Apolipoprotein D interacts with the long-form leptin receptor: a hypothalamic function in the control of energy homeostasis". FASEB J. 15 (7): 1329–31. doi:10.1096/fj.00-0530fje. PMID11344130.
Sánchez D, Ganfornina MD, Martínez S (2002). "Expression pattern of the lipocalin apolipoprotein D during mouse embryogenesis". Mech. Dev. 110 (1–2): 225–9. doi:10.1016/S0925-4773(01)00578-0. PMID11744388.
Desai PP, Hendrie HC, Evans RM, et al. (2003). "Genetic variation in apolipoprotein D affects the risk of Alzheimer disease in African-Americans". Am. J. Med. Genet. B Neuropsychiatr. Genet. 116 (1): 98–101. doi:10.1002/ajmg.b.10798. PMID12497622.
Kang MK, Kameta A, Shin KH, et al. (2003). "Senescence-associated genes in normal human oral keratinocytes". Exp. Cell Res. 287 (2): 272–81. doi:10.1016/S0014-4827(03)00061-2. PMID12837283.
Thomas EA, Laws SM, Sutcliffe JG, et al. (2003). "Apolipoprotein D levels are elevated in prefrontal cortex of subjects with Alzheimer's disease: no relation to apolipoprotein E expression or genotype". Biol. Psychiatry. 54 (2): 136–41. doi:10.1016/S0006-3223(02)01976-5. PMID12873803.