Cellular retinoic acid binding protein is associated with mitochondria.
We report that immunohistochemical staining for cellular retinoic acid-binding protein (CRABP) was restricted to the cytoplasm of cortical cells in bovine adrenal. In contrast, staining for the similar protein, cellular retinol-binding protein (CRBP), was found throughout these cells. After transfections of CRABP and CRBP into cultured cells, immunofluorescence analyses again revealed cytoplasmic restriction only for CRABP, with a pronounced punctate appearance. Use of organelle-specific fluorochromes indicated that CRABP immunofluorescence overlaid exactly with the pattern of the mitochondrial-specific fluorochrome. Confirmation of this association came with subcellular fractionation of the adrenal cortex. CRABP, but not CRBP, co-sedimented with the mitochondria, a novel finding for a member of this superfamily of cellular lipid-binding proteins.
Ruff
S J
SJ
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
Ong
D E
DE
D016475:3T3 Cells; D000302:Adrenal Cortex / Q000166:cytology*; D000818:Animals; D019556:COS Cells; D002417:Cattle; D002467:Cell Nucleus / Q000648:ultrastructure; D002522:Chlorocebus aethiops; D007150:Immunohistochemistry / Q000379:methods; D051379:Mice; D008928:Mitochondria / Q000648:ultrastructure*; D018168:Receptors, Retinoic Acid / Q000032:analysis* / Q000235:genetics; D011994:Recombinant Proteins / Q000032:analysis; D014162:Transfection
D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins; C082927:retinoic acid binding protein I, cellular