title: Functional conservation for lipid storage droplet association among Perilipin, ADRP, and TIP47 (PAT)-related proteins in mammals, Drosophila, and Dictyostelium.
abstract: Intracellular neutral lipid storage droplets are essential organelles of eukaryotic cells, yet little is known about the proteins at their surfaces or about the amino acid sequences that target proteins to these storage droplets. The mammalian proteins Perilipin, ADRP, and TIP47 share extensive amino acid sequence similarity, suggesting a common function. However, while Perilipin and ADRP localize exclusively to neutral lipid storage droplets, an association of TIP47 with intracellular lipid droplets has been controversial. We now show that GFP-tagged TIP47 co-localizes with isolated intracellular lipid droplets. We have also detected a close juxtaposition of TIP47 with the surfaces of lipid storage droplets using antibodies that specifically recognize TIP47, further indicating that TIP47 associates with intracellular lipid storage droplets. Finally, we show that related proteins from species as diverse as Drosophila and Dictyostelium can also target mammalian or Drosophila lipid droplet surfaces in vivo. Thus, sequence and/or structural elements within this evolutionarily ancient protein family are necessary and sufficient to direct association to heterologous intracellular lipid droplet surfaces, strongly indicating that they have a common function for lipid deposition and/or mobilization.
authors.affiliation: Membrane Regulation Section, Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20992-8028, USA.
authors.forename: Shinji
authors.initials: S
authors.lastname: Miura
authors.forename: Jai-Wei
authors.initials: JW
authors.lastname: Gan
authors.forename: Joseph
authors.initials: J
authors.lastname: Brzostowski
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Parisi
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Schultz
authors.forename: Constantine
authors.initials: C
authors.lastname: Londos
authors.forename: Brian
authors.initials: B
authors.lastname: Oliver
authors.forename: Alan R
authors.initials: AR
authors.lastname: Kimmel
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D016466:CHO Cells; D002352:Carrier Proteins; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004023:Dictyostelium; D004330:Drosophila; D049452:Green Fluorescent Proteins; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008322:Mammals; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D000070778:Perilipin-1; D000070780:Perilipin-2; D000070796:Perilipin-3; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D011257:Pregnancy Proteins; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D033921:Vesicular Transport Proteins
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; C000602982:PLIN2 protein, human; C038196:PLIN3 protein, human; D000070778:Perilipin-1; D000070780:Perilipin-2; D000070796:Perilipin-3; D010750:Phosphoproteins; C000602983:Plin2 protein, mouse; D011257:Pregnancy Proteins; D011993:Recombinant Fusion Proteins; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins