Publications

• Identification of genes and pathways involved in the synthesis of Mead acid (20:3n-9), an indicator of essential fatty acid deficiency.

  Ichi I., Kono N., Arita Y., Haga S., Arisawa K., Yamano M., Nagase M., Fujiwara Y., Arai H.

  In mammals, 5,8,11-eicosatrienoic acid (Mead acid, 20:3n-9) is synthesized from oleic acid during a state of essential fatty acid deficiency (EFAD). Mead acid is thought to be produced by the same enzymes that synthesize arachidonic acid and eicosapentaenoic acid, but the genes and the pathways in ... >> More

  In mammals, 5,8,11-eicosatrienoic acid (Mead acid, 20:3n-9) is synthesized from oleic acid during a state of essential fatty acid deficiency (EFAD). Mead acid is thought to be produced by the same enzymes that synthesize arachidonic acid and eicosapentaenoic acid, but the genes and the pathways involved in the conversion of oleic acid to Mead acid have not been fully elucidated. The levels of polyunsaturated fatty acids in cultured cells are generally very low compared to those in mammalian tissues. In this study, we found that cultured cells, such as NIH3T3 and Hepa1-6 cells, have significant levels of Mead acid, indicating that cells in culture are in an EFAD state under normal culture conditions. We then examined the effect of siRNA-mediated knockdown of fatty acid desaturases and elongases on the level of Mead acid, and found that knockdown of Elovl5, Fads1, or Fads2 decreased the level of Mead acid. This and the measured levels of possible intermediate products for the synthesis of Mead acid such as 18:2n-9, 20:1n-9 and 20:2n-9 in the knocked down cells indicate two pathways for the synthesis of Mead acid: pathway 1) 18:1n-9→(Fads2)→18:2n-9→(Elovl5)→20:2n-9→(Fads1)→20:3n-9 and pathway 2) 18:1n-9→(Elovl5)→20:1n-9→(Fads2)→20:2n-9→(Fads1)→20:3n-9. << Less

  Biochim. Biophys. Acta 1841:204-213(2014) [PubMed] [EuropePMC]

• ELOVL1 production of C24 acyl-CoAs is linked to C24 sphingolipid synthesis.

  Ohno Y., Suto S., Yamanaka M., Mizutani Y., Mitsutake S., Igarashi Y., Sassa T., Kihara A.

  Very long-chain fatty acids (VLCFAs) exert a variety of cellular functions and are associated with numerous diseases. However, the precise pathway behind their elongation has remained elusive. Moreover, few regulatory mechanisms for VLCFAs synthesis have been identified. Elongases catalyze the fir ... >> More

  Very long-chain fatty acids (VLCFAs) exert a variety of cellular functions and are associated with numerous diseases. However, the precise pathway behind their elongation has remained elusive. Moreover, few regulatory mechanisms for VLCFAs synthesis have been identified. Elongases catalyze the first of four steps in the VLCFA elongation cycle; mammals have seven elongases (ELOVL1-7). In the present study, we determined the precise substrate specificities of all the ELOVLs by in vitro analyses. Particularly notable was the high activity exhibited by ELOVL1 toward saturated and monounsaturated C20- and C22-CoAs, and that it was essential for the production of C24 sphingolipids, which are unique in their capacity to interdigitate within the membrane as a result of their long chain length. We further established that ELOVL1 activity is regulated with the ceramide synthase CERS2, an enzyme essential for C24 sphingolipid synthesis. This regulation may ensure that the production of C24-CoA by elongation is coordinated with its utilization. Finally, knockdown of ELOVL1 caused a reduction in the activity of the Src kinase LYN, confirming that C24-sphingolipids are particularly important in membrane microdomain function. << Less

  Proc. Natl. Acad. Sci. U.S.A. 107:18439-18444(2010) [PubMed] [EuropePMC]

  This publication is cited by 15 other entries.