A novel mitochondrial carnitine-acylcarnitine translocase induced by partial hepatectomy and fasting.
The carnitine-dependent transport of long-chain fatty acids is essential for fatty acid catabolism. In this system, the fatty acid moiety of acyl-CoA is transferred enzymatically to carnitine, and the resultant product, acylcarnitine, is imported into the mitochondrial matrix through a transporter named carnitine-acylcarnitine translocase (CACT). Here we report a novel mammalian protein homologous to CACT. The protein, designated as CACL (CACT-like), is localized to the mitochondria and has palmitoylcarnitine transporting activity. The tissue distribution of CACL is similar to that of CACT; both are expressed at a higher level in tissues using fatty acids as fuels, except in the brain, where only CACL is expressed. In addition, CACL is induced by partial hepatectomy or fasting. Thus, CACL may play an important role cooperatively with its homologue CACT in a stress-induced change of lipid metabolism, and may be specialized for the metabolism of a distinct class of fatty acids involved in brain function.
Sekoguchi
Ei
E
Department of Geriatric Research, National Institute for Longevity Sciences, Obu, Aichi 474-8522, Japan.
Sato
Norihiro
N
Yasui
Akihiro
A
Fukada
Shinji
S
Nimura
Yuji
Y
Aburatani
Hiroyuki
H
Ikeda
Kyoji
K
Matsuura
Akira
A
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D015152:Blotting, Northern; D015153:Blotting, Western; D001921:Brain / Q000502:physiology; D002331:Carnitine / Q000031:analogs & derivatives* / Q000737:chemistry; D002333:Carnitine Acyltransferases / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology*; D018076:DNA, Complementary / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005508:Food Deprivation; D005816:Genetic Complementation Test; D006801:Humans; D007150:Immunohistochemistry; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000201:enzymology* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010172:Palmitoylcarnitine / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014018:Tissue Distribution
D018076:DNA, Complementary; D005227:Fatty Acids; D024101:Mitochondrial Proteins; C116917:acylcarnitine; D010172:Palmitoylcarnitine; D002333:Carnitine Acyltransferases; C478391:SLC25A29 protein, human; D002331:Carnitine