The mouse ACOT gene cluster comprises six genes with localizations in cytosol (ACOT1), mitochondria (ACOT2), and peroxisomes (ACOT3-6). The corresponding human gene cluster contains only three genes (ACOT1, ACOT2, and ACOT4) coding for full-length thioesterase proteins only ACOT4 is peroxisomal
(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Opisthokonta: NE > Metazoa: NE > Eumetazoa: NE > Bilateria: NE > Deuterostomia: NE > Chordata: NE > Craniata: NE > Vertebrata: NE > Gnathostomata: NE > Teleostomi: NE > Euteleostomi: NE > Sarcopterygii: NE > Dipnotetrapodomorpha: NE > Tetrapoda: NE > Amniota: NE > Mammalia: NE > Theria: NE > Eutheria: NE > Boreoeutheria: NE > Euarchontoglires: NE > Glires: NE > Rodentia: NE > Myomorpha: NE > Muroidea: NE > Muridae: NE > Murinae: NE > Mus [genus]: NE > Mus [subgenus]: NE > Mus musculus: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MHAFTTQNPNRMAPTVILEPAGGCLCDQPVHIAVRGLAPEQPVTLRSVLR DEKGALFRAHARYRADSHGELDLARTPALGGSFSGLEPMGLLWAMEPDRP FWRLIKRDVQTPFVVELEVLDGHEPDGGQRLARAVHERHFMAPGVRRVPV REGRVRATLFLPPGTGPFPGIIDLFGIGSGLLEYRASLLAGKGFAVMALA YNNYEDLPKDMDIIHLEYFEEAVTYLLSHPQVTGSGVGVLGISKGGELGF AMASFLKNITAAVIINGSISNIGGNLQYKDETVPSVGINTKRVKRTKDGL KDIVDLLNNPLEGPDQKSLIPVERSDTAFLFLVGQDDHNWKSEFYAREAS KRLQAHGKEKPQIICYPETGHHIEPPYFPLCKASLNSLVGGPVIWGGEPR AHAMAQVDAWQQLQTFFHNHLDGKKKTIPAKL
References
Title: Analysis of the mouse and human acyl-CoA thioesterase (ACOT) gene clusters shows that convergent, functional evolution results in a reduced number of human peroxisomal ACOTs Hunt MC, Rautanen A, Westin MA, Svensson LT, Alexson SE Ref: FASEB Journal, 20:1855, 2006 : PubMed
The maintenance of cellular levels of free fatty acids and acyl-CoAs, the activated form of free fatty acids, is extremely important, as imbalances in lipid metabolism have serious consequences for human health. Acyl-coenzyme A (CoA) thioesterases (ACOTs) hydrolyze acyl-CoAs to the free fatty acid and CoASH, and thereby have the potential to regulate intracellular levels of these compounds. We previously identified and characterized a mouse ACOT gene cluster comprised of six genes that apparently arose by gene duplications encoding acyl-CoA thioesterases with localizations in cytosol (ACOT1), mitochondria (ACOT2), and peroxisomes (ACOT3-6). However, the corresponding human gene cluster contains only three genes (ACOT1, ACOT2, and ACOT4) coding for full-length thioesterase proteins, of which only one is peroxisomal (ACOT4). We therefore set out to characterize the human genes, and we show here that the human ACOT4 protein catalyzes the activities of three mouse peroxisomal ACOTs (ACOT3, 4, and 5), being active on succinyl-CoA and medium to long chain acyl-CoAs, while ACOT1 and ACOT2 carry out similar functions to the corresponding mouse genes. These data strongly suggest that the human ACOT4 gene has acquired the functions of three mouse genes by a functional convergent evolution that also provides an explanation for the unexpectedly low number of human genes.
Title: Molecular cloning and characterization of two mouse peroxisome proliferator-activated receptor alpha (PPARalpha)-regulated peroxisomal acyl-CoA thioesterases Westin MA, Alexson SE, Hunt MC Ref: Journal of Biological Chemistry, 279:21841, 2004 : PubMed
Peroxisomes are organelles that function in the beta-oxidation of long- and very long-chain acyl-CoAs, bile acid-CoA intermediates, prostaglandins, leukotrienes, thromboxanes, dicarboxylic fatty acids, pristanic acid, and xenobiotic carboxylic acids. The very long- and long-chain acyl-CoAs are mainly chain-shortened and then transported to mitochondria for further metabolism. We have now identified and characterized two peroxisomal acyl-CoA thioesterases, named PTE-Ia and PTE-Ic, that hydrolyze acyl-CoAs to the free fatty acid and coenzyme A. PTE-Ia and PTE-Ic show 82% sequence identity at the amino acid level, and a putative peroxisomal type 1 targeting signal of -AKL was identified at the carboxyl-terminal end of both proteins. Localization experiments using green fluorescent fusion protein showed PTE-Ia and PTE-Ic to be localized in peroxisomes. Despite their high level of sequence identity, we show that PTE-Ia is mainly active on long-chain acyl-CoAs, whereas PTE-Ic is mainly active on medium-chain acyl-CoAs. Lack of regulation of enzyme activity by free CoASH suggests that PTE-Ia and PTE-Ic regulate intraperoxisomal levels of acyl-CoA, and they may have a function in termination of beta-oxidation of fatty acids of different chain lengths. Tissue expression studies revealed that PTE-Ia is highly expressed in kidney, whereas PTE-Ic is most highly expressed in spleen, brain, testis, and proximal and distal intestine. Both PTE-Ia and PTE-Ic were highly up-regulated in mouse liver by treatment with the peroxisome proliferator WY-14,643 and by fasting in a peroxisome proliferator-activated receptor alpha-dependent manner. These data show that PTE-Ia and PTE-Ic have different functions based on different substrate specificities and tissue expression.
Title: Peroxisome proliferator-induced long chain acyl-CoA thioesterases comprise a highly conserved novel multi-gene family involved in lipid metabolism Hunt MC, Nousiainen SE, Huttunen MK, Orii KE, Svensson LT, Alexson SE Ref: Journal of Biological Chemistry, 274:34317, 1999 : PubMed
Long chain acyl-CoA esters are important intermediates in degradation and synthesis of fatty acids, as well as having important functions in regulation of intermediary metabolism and gene expression. Although the physiological functions for most acyl-CoA thioesterases have not yet been elucidated, previous data suggest that these enzymes may be involved in lipid metabolism by modulation of cellular concentrations of acyl-CoAs and fatty acids. In line with this, we have cloned four highly homologous acyl-CoA thioesterase genes from mouse, showing multiple compartmental localizations. The nomenclature for these genes has tentatively been assigned as CTE-I (cytosolic), MTE-I (mitochondrial), and PTE-Ia and Ib (peroxisomal), based on the identification of putative targeting signals. Although the various isoenzymes show between 67% and 94% identity at amino acid level, each individual enzyme shows a specific tissue expression. Our data suggest that all four genes are located within a very narrow cluster on chromosome 12 in mouse, similar to a sequence cluster on human chromosome 14, which identified four genes homologous to the mouse thioesterase genes. Four related genes were also identified in Caenorhabditis elegans, all containing putative PTS1 targeting signals, suggesting that the ancestral type I thioesterase gene(s) is/are of peroxisomal origin. All four thioesterases are differentially expressed in tissues examined, but all are inducible at mRNA level by treatment with the peroxisome proliferator clofibrate, or during the physiological condition of fasting, both of which conditions cause a perturbation in overall lipid homeostasis. These results strongly support the existence of a novel multi-gene family cluster of mouse acyl-CoA thioesterases, each with a distinct function in lipid metabolism.
Mus musculus (Mouse) Abhydrolase domain-containing protein 10, mitochondrial