ABCD4 may transport Cbl from lysosomal lumen to cytosol

Stable Identifier
Reaction [transition]
Homo sapiens
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ATP-binding cassette sub-family D member 4 (ABCD4), originally thought to be localised to the peroxisomal membrane, has since been demonstrated to colocalise with the lysosomal proteins LAMP1 and LMBD1. Mutations modifying the ATPase domain of ABCD4 can affect its function and suggests a role in the intracellular transport of cobalamin (Cbl, aka vitamin B12) (Coelho et al. 2012). Further evidence for this role comes from mutation studies in ABCD4 that can cause methylmalonic aciduria and homocystinuria type CblJ (MAHCJ; MIM:614857), a disorder of Cbl metabolism characterised by decreased levels of the coenzymes adenosylcobalamin (AdoCbl) and methylcobalamin (MeCbl). This disease mimics the cblF defect caused by LMBRD1 mutations (Coelho et al. 2012).

Literature References
PubMed ID Title Journal Year
22922874 Mutations in ABCD4 cause a new inborn error of vitamin B12 metabolism

Coelho, D, Kim, JC, Miousse, IR, Fung, S, du Moulin, M, Buers, I, Suormala, T, Burda, P, Frapolli, M, Stucki, M, Nürnberg, P, Thiele, H, Robenek, H, Höhne, W, Longo, N, Pasquali, M, Mengel, E, Watkins, D, Shoubridge, EA, Majewski, J, Rosenblatt, DS, Fowler, B, Rutsch, F, Baumgartner, MR

Nat. Genet. 2012
Participant Of
Catalyst Activity
Catalyst Activity
ABC-type transmembrane transporter activity of ABCD4 [lysosomal membrane]
Physical Entity
Orthologous Events
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