title: The lack of the C-terminal domain of adipose triglyceride lipase causes neutral lipid storage disease through impaired interactions with lipid droplets.
abstract: BACKGROUND
  The molecular mechanisms by which triglycerides in lipid droplets (LDs) are synthesized, stored, and degraded need to be elucidated.
  
  
  OBJECTIVE
  The objectives were to report siblings with neutral lipid storage disease with myopathy (NLSDM) with a novel mutation of adipose triglyceride lipase (ATGL) and determine whether the C-terminal part of ATGL containing the hydrophobic region plays a role in the interaction with LDs.
  
  
  METHODS
  Skin fibroblasts and peripheral blood leukocytes were obtained from NLSDM patients. In vitro experiments were performed with fibroblasts and COS7 cells.
  
  
  METHODS
  Transfection studies were used to assess the effects of various recombinant ATGL proteins on lipase activities and lipid contents. Fluorescence microscopy were used for determination of intracellular distribution of ATGL proteins.
  
  
  RESULTS
  The direct sequence of ATGL cDNA reveals that a patient is a homozygote for the 4-bp deletion, leading to a premature stop codon and causes the lack of the C terminus of the protein including the hydrophobic domain. Overexpressed control ATGL in NLSDM fibroblasts was found around the rims of LDs and caused significantly reduced cellular lipid accumulation. In contrast, NLSDM ATGL was homogeneously located in the cytoplasm despite the presence of LDs and had almost no effect on LD degradation despite its similar lipase activity. A series of C-terminal truncated ATGLs without the intact hydrophobic domain failed to localize around and degrade LDs.
  
  
  CONCLUSIONS
  These findings indicate that the domain including the hydrophobic region of ATGL was essential for association with LDs.
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan. nihisak@med.kyushu-u.ac.jp
authors.forename: Kunihisa
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Toyoshi
authors.initials: T
authors.lastname: Inoguchi
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Maeda
authors.forename: Naoki
authors.initials: N
authors.lastname: Nakashima
authors.forename: Asako
authors.initials: A
authors.lastname: Kuwano
authors.forename: Erina
authors.initials: E
authors.lastname: Eto
authors.forename: Noriko
authors.initials: N
authors.lastname: Ueno
authors.forename: Shuji
authors.initials: S
authors.lastname: Sasaki
authors.forename: Fumi
authors.initials: F
authors.lastname: Sawada
authors.forename: Masakazu
authors.initials: M
authors.lastname: Fujii
authors.forename: Yuka
authors.initials: Y
authors.lastname: Matoba
authors.forename: Shinji
authors.initials: S
authors.lastname: Sumiyoshi
authors.forename: Hisaya
authors.initials: H
authors.lastname: Kawate
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Takayanagi
mesh_terms: D000818:Animals; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008049:Lipase / Q000737:chemistry / Q000235:genetics*; D050356:Lipid Metabolism; D052439:Lipid Metabolism Disorders / Q000235:genetics*; D008875:Middle Aged; D009135:Muscular Diseases / Q000235:genetics*; D009154:Mutation; D017434:Protein Structure, Tertiary; D014280:Triglycerides / Q000378:metabolism*; D000217:Acyltransferases
chemical_list: D008049:Lipase; D014280:Triglycerides; C494794:PNPLA2 protein, human; D000217:Acyltransferases