Title: | Functional characterization of the Bombyx mori fatty acid transport protein (BmFATP) within the silkmoth pheromone gland |
Author(s): | Ohnishi A; Hashimoto K; Imai K; Matsumoto S; |
Address: | "Molecular Entomology Laboratory, Advanced Science Institute, RIKEN, Wako, Saitama 351-0198, Japan" |
ISSN/ISBN: | 0021-9258 (Print) 0021-9258 (Linking) |
Abstract: | "Fatty acid transport protein (FATP) is an evolutionarily conserved membrane-bound protein that facilitates the uptake of extracellular long chain fatty acids. In humans and mice, six FATP isoforms have been identified and their tissue-specific distributions suggest that each plays a discrete role in lipid metabolism in association with fatty acid uptake. While the presence of FATP homologs in insects has been demonstrated, their functional role remains to be characterized. Pheromonogenesis is defined as the dynamic period in which all machinery required for sex pheromone biosynthesis is generated and organized within the pheromone gland (PG) cells. By exploiting this unique system in the PG of the silkmoth, Bombyx mori, we found that BmFATP is predominantly expressed in the PG and undergoes up-regulation 1 day prior to eclosion. Before eclosion, B. mori PG cells accumulate cytoplasmic lipid droplets (LDs), which play a role in storing the pheromone (bombykol) precursor fatty acid in the form of triacylglycerol. RNAi-mediated gene silencing of BmFATP in vivo significantly suppressed LD accumulation by preventing the synthesis of triacylglycerols and resulted in a significant reduction in bombykol production. These results, in conjunction with the findings that BmFATP stimulates the uptake of extracellular long-chain fatty acids and BmFATP knockdown reduces cellular long-chain acyl-CoA synthetase activity, suggest that BmFATP plays an essential role in bombykol biosynthesis by stimulating both LD accumulation and triacylglycerol synthesis via a process called vectorial acylation that couples the uptake of extracellular fatty acids with activation to CoA thioesters during pheromonogenesis" |
Keywords: | Animals Bombyx/genetics/*metabolism Exocrine Glands/*metabolism Fatty Acid-Binding Proteins/genetics/*metabolism Fatty Acids/genetics/metabolism Fatty Alcohols/metabolism Humans Insect Proteins/genetics/*metabolism Mice Molting/physiology Pheromones/*bios; |
Notes: | "MedlineOhnishi, Atsushi Hashimoto, Kana Imai, Kiyohiro Matsumoto, Shogo eng Research Support, Non-U.S. Gov't 2008/12/30 J Biol Chem. 2009 Feb 20; 284(8):5128-36. doi: 10.1074/jbc.M806072200. Epub 2008 Dec 26" |