Adipose differentiation-related protein has two independent domains for targeting to lipid droplets.
Adipose differentiation-related protein (ADRP) is a protein found in lipid droplets of many cell types. In contrast to several other proteins localized to lipid droplets, ADRP does not have a long hydrophobic domain. We investigated as to which portion of the molecule is important for localization to pre-existing lipid droplets. By truncating from the carboxyl-terminus, a segment of amino acids (aa) 1-181 of ADRP was found distributed to lipid droplets, but further deletion, e.g., aa 1-155, caused diffuse distribution in the cytoplasm. By amino terminal truncation, aa 167-426 was found mostly cytoplasmic, but surprisingly, a shorter mutant, e.g., aa 277-426, was distributed to lipid droplets. Still shorter mutants, e.g., aa 302-426, often distributed to mitochondria, and a mutant lacking aa 154-174 was found in the cytoplasm. Interestingly, expression of either aa 1-181 or aa 277-426, which are not overlapping each other, induced de novo formation of lipid droplets. The result indicates that ADRP has two independent domains related to its localization and lipid droplet biogenesis. The unique property found in the present study may be related to physiological function of ADRP.
Nakamura
Noriko
N
Department of Anatomy and Molecular Cell Biology, Graduate School of Medicine, Nagoya University, 65 Tsurumai, Showa, Nagoya 466-8550, Japan.
Fujimoto
Toyoshi
T
D016475:3T3 Cells; D000273:Adipose Tissue / Q000166:cytology; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008164:Luminescent Proteins / Q000378:metabolism; D007614:Macropodidae; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology*; D051379:Mice; D018613:Microscopy, Confocal; D009154:Mutation; D000070780:Perilipin-2; D017434:Protein Structure, Tertiary; D051381:Rats; D014162:Transfection
D008055:Lipids; D008164:Luminescent Proteins; D008565:Membrane Proteins; D000070780:Perilipin-2; C000602983:Plin2 protein, mouse; C000602984:Plin2 protein, rat; D049452:Green Fluorescent Proteins