Inherited mutations in the ABCD1 gene encoding the ALD protein (ALDP) a peroxisomal trans membrane protein of the ABC transporter superfamily lead to X-ALD. The substrate that ALDP transports as well as the detailed cell type specificity of expression is still unknown.
In cooperation with Romana Höftberger and Herbert Budka (Medical University Vienna, Austria), we have examined the expression of ALDP in various human tissues and cell lines by multiple-tissue RNA expression array analysis, Western blot analysis, and immunohistochemistry. The specific expression pattern suggests a functional link between ALDP and proopiomelanocortin (POMC)-derived peptide hormones.
Fig: Expression of ALDP in human pituitary gland. Immunohistochemical investigations of 16 pituitary glands reveal ALDP expression primarily in corticotroph cells of the adenohypophysis. ALDP is found predominantly in the intermediate zone and to a lesser extent in the anterior lobe.
To read more about the expression of human ABCD1 -pdf-