title: A photocytes-associated fatty acid-binding protein from the light organ of adult Taiwanese firefly, Luciola cerata.
abstract: BACKGROUND
  Intracellular fatty acid-binding proteins (FABPs) are considered to be an important energy source supplier in lipid metabolism; however, they have never been reported in any bioluminescent tissue before. In this study, we determined the structural and functional characteristics of a novel FABP (lcFABP) from the light organ of adult Taiwanese firefly, Luciola cerata, and showed anatomical association of lcFABP with photocytes.
  
  
  RESULTS
  Our results demonstrated the primary structure of lcFABP deduced from the cDNA clone of light organ shares structural homologies with other insect and human FABPs. In vitro binding assay indicated the recombinant lcFABP binds saturated long chain fatty acids (C₁₄-C₁₈) more strongly than other fatty acids and firefly luciferin. In addition, tissue distribution screening assay using a rabbit antiserum specifically against the N-terminal sequence of lcFABP confirmed the light organ-specific expression of lcFABP. In the light organ, the lcFABP constituted about 15% of total soluble proteins, and was detected in both cytosol and nucleus of photocytes.
  
  
  CONCLUSIONS
  The specific localization of abundant lcFABP in the light organ suggests that sustained bioluminescent flashes in the light organ might be a high energy demanding process. In photocytes, lcFABP might play a key role in providing long chain fatty acids to peroxisomes for the luciferase-catalyzed long chain acyl-CoA synthetic reaction.
authors.affiliation: Institute of Molecular and Cellular Biology, National Tsing-Hua University, Hsinchu, Taiwan.
authors.forename: King-Siang
authors.initials: KS
authors.lastname: Goh
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Li
mesh_terms: D000375:Aging / Q000502:physiology*; D000595:Amino Acid Sequence; D000825:Animal Structures / Q000166:cytology* / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D001681:Biological Assay; D003001:Cloning, Molecular; D050556:Fatty Acid-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D048888:Fireflies / Q000166:cytology* / Q000378:metabolism*; D005453:Fluorescence; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008027:Light; D008297:Male; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011485:Protein Binding; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013624:Taiwan
chemical_list: D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D011994:Recombinant Proteins