The crystal structure of human mitochondrial 3-ketoacyl-CoA thiolase (T1): insight into the reaction mechanism of its thiolase and thioesterase activities

Kiema, T.-R.; Harijan, R.K.; Stróżyk, M.; Fukao, Toshiyuki; Alexson, Stefan E.H.; Wierenga, Rik K.

doi:10.1107/s1399004714023827

Cited by 33 publications

(32 citation statements)

References 56 publications

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“…Only the mutation of Cys458 to Ser impaired glucose deprivation-induced TPb oxidation ( Figure 5C), suggesting that Cys458, conserved across several species ( Figure S5C), is the major site of oxidation in TPb. A structural analysis of thiolase family members suggested that Cys458 may be essential for the enzymatic activity of thiolase, during which it provides a proton to acetyl-CoA and then removes a proton from the incoming CoA (Haapalainen et al, 2006;Kiema et al, 2014). Mutating Cys458 suppressed the KACT activity of TPb not only in vitro but also in cells under normal conditions ( Figure 5D; Figures S5D and S5E), confirming the requirement of this cysteine for the enzymatic activity of TPb.…”

Section: Nur77 Interaction With Tpb In Mitochondria Facilitates Cell mentioning

confidence: 57%

Nuclear Receptor Nur77 Facilitates Melanoma Cell Survival under Metabolic Stress by Protecting Fatty Acid Oxidation

Wang

Zheng

et al. 2018

Molecular Cell

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Fatty acid oxidation (FAO) is crucial for cells to overcome metabolic stress by providing ATP and NADPH. However, the mechanism by which FAO is regulated in tumors remains elusive. Here we show that Nur77 is required for the metabolic adaptation of melanoma cells by protecting FAO. Glucose deprivation activates ERK2 to phosphorylate and induce Nur77 translocation to the mitochondria, where Nur77 binds to TPβ, a rate-limiting enzyme in FAO. Although TPβ activity is normally inhibited by oxidation under glucose deprivation, the Nur77-TPβ association results in Nur77 self-sacrifice to protect TPβ from oxidation. FAO is therefore able to maintain NADPH and ATP levels and prevent ROS increase and cell death. The Nur77-TPβ interaction further promotes melanoma metastasis by facilitating circulating melanoma cell survival. This study demonstrates a novel regulatory function of Nur77 with linkage of the FAO-NADPH-ROS pathway during metabolic stress, suggesting Nur77 as a potential therapeutic target in melanoma.

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Section: Nur77 Interaction With Tpb In Mitochondria Facilitates Cell mentioning

confidence: 57%

Nuclear Receptor Nur77 Facilitates Melanoma Cell Survival under Metabolic Stress by Protecting Fatty Acid Oxidation

Wang

Zheng

et al. 2018

Molecular Cell

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“…Moreover, it was reported by others that enzymatically active thiolase is a dimer or tetramer (24). Thus, p46Shc can directly bind to ACAA2 in mitochondria with K D ϭ 54.62 Ϯ 34.87 nM (Fig.…”

Section: P46shc Is the Only Mitochondrial Shc Isoform Under Physiologmentioning

confidence: 82%

p46Shc Inhibits Thiolase and Lipid Oxidation in Mitochondria

Tomilov

Tomilova

Shan

et al. 2016

Journal of Biological Chemistry

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Although the p46Shc isoform has been known to be mitochondrially localized for 11 years, its function in mitochondria has been a mystery. We confirmed p46Shc to be mitochondrially localized and showed that the major mitochondrial partner of p46Shc is the lipid oxidation enzyme 3-ketoacylCoA thiolase ACAA2, to which p46Shc binds directly and with a strong affinity. Increasing p46Shc expression inhibits, and decreasing p46Shc stimulates enzymatic activity of thiolase in vitro. Thus, we suggest p46Shc to be a negative mitochondrial thiolase activity regulator, and reduction of p46Shc expression activates thiolase. This is the first demonstration of a protein that directly binds and controls thiolase activity. Thiolase was thought previously only to be regulated by metabolite balance and steadystate flux control. Thiolase is the last enzyme of the mitochondrial fatty acid beta-oxidation spiral, and thus is important for energy metabolism. Mice with reduction of p46Shc are lean, resist obesity, have higher lipid oxidation capacity, and increased thiolase activity. The thiolase-p46Shc connection shown here in vitro and in organello may be an important underlying mechanism explaining the metabolic phenotype of Shcdepleted mice in vivo.Shc proteins have three isoforms: p46, p52, and p66, and have major effects on metabolism (1-4). p52Shc contacts the insulin receptor and regulates the signaling between the IRS1 and Ras pathway (5). In 2004, it was demonstrated that the major mitochondrial Shc isoform is p46Shc (6), but since that time the mitochondrial partner and physiological function of p46Shc has been a mystery. Here we show the mitochondrial partner and function of p46Shc, and suggest how this could contribute to the obesity-resistance observed in ShcKO mice.There are three isoforms at the mammalian Shc locus, the highly expressed isoforms p46Shc and p52Shc, and the minor p66Shc. All three Shc isoforms are derived from a single DNA locus. First, two mRNA are produced: p66Shc and p52/46Shc by means of trans-splicing. The p66Shc mRNA has start codons for all three Shc isoforms. The p52/46Shc-mRNA does not have a start codon for p66Shc and only produces p52Shc and p46Shc (7). For this reason, knockdowns of either p66Shc, or all three Shc isoforms together have been achieved to date. There are two mouse models of Shc depletion produced to date: ShcL, also known as p66ShcKO developed by the Tom Prolla group (ShcProlla, Ref. 4), and Shc mice developed by the Pelicci group (ShcP or ShcPelicci, also known as p66Shc (Ϫ/Ϫ, Refs. 3,4,8,9). Names in literature for these two models can be described by these definitions: ShcL, ShcProlla; ShcKO, ShcP ϭ ShcPelicci ϭ p66Shc(Ϫ/Ϫ).Briefly, ShcL or ShcProlla mice have a deletion of only the minor p66Shc isoform and have no health benefits: ShcL mice are not lean, do not resist weight gain on high fat diets (HFD), 2 and are not longer-lived on HFD, and do not have improved insulin sensitivity (4). Thus p66Shc deletion by itself does not result in health benefits.By contrast, ShcKO have...

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“…The N ‐ and C ‐terminal residues are far away from the catalytic site, being on the opposite site of the subunit. The built model of each subunit has the distinct conserved thiolase superfamily fold that can be subdivided into the N ‐terminal domain, loop domain, and C ‐terminal domain (Haapalainen et al, ; Kiema et al, , ). The N ‐ and C ‐terminal domains have the same βαβαβαββ‐topology and these two domains jointly form a five‐layered α‐β‐α‐β‐α structure.…”

Section: Structural Features Of the T2 Thiolasementioning

confidence: 99%

Mutation update on ACAT1 variants associated with mitochondrial acetoacetyl‐CoA thiolase (T2) deficiency

et al. 2019

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Mitochondrial acetoacetyl‐CoA thiolase (T2, encoded by the ACAT1 gene) deficiency is an inherited disorder of ketone body and isoleucine metabolism. It typically manifests with episodic ketoacidosis. The presence of isoleucine‐derived metabolites is the key marker for biochemical diagnosis. To date, 105 ACAT1 variants have been reported in 149 T2‐deficient patients. The 56 disease‐associated missense ACAT1 variants have been mapped onto the crystal structure of T2. Almost all these missense variants concern residues that are completely or partially buried in the T2 structure. Such variants are expected to cause T2 deficiency by having lower in vivo T2 activity because of lower folding efficiency and/or stability. Expression and activity data of 30 disease‐associated missense ACAT1 variants have been measured by expressing them in human SV40‐transformed fibroblasts. Only two variants (p.Cys126Ser and p.Tyr219His) appear to have equal stability as wild‐type. For these variants, which are inactive, the side chains point into the active site. In patients with T2 deficiency, the genotype does not correlate with the clinical phenotype but exerts a considerable effect on the biochemical phenotype. This could be related to variable remaining residual T2 activity in vivo and has important clinical implications concerning disease management and newborn screening.

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The crystal structure of human mitochondrial 3-ketoacyl-CoA thiolase (T1): insight into the reaction mechanism of its thiolase and thioesterase activities

Cited by 33 publications

References 56 publications

Nuclear Receptor Nur77 Facilitates Melanoma Cell Survival under Metabolic Stress by Protecting Fatty Acid Oxidation

Nuclear Receptor Nur77 Facilitates Melanoma Cell Survival under Metabolic Stress by Protecting Fatty Acid Oxidation

p46Shc Inhibits Thiolase and Lipid Oxidation in Mitochondria

Mutation update on ACAT1 variants associated with mitochondrial acetoacetyl‐CoA thiolase (T2) deficiency

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