Comparative Biochemical Studies of the Murine Fatty Acid Transport Proteins (FATP) Expressed in Yeast

DiRusso, Concetta C.; Li, Hong; Darwis, Dina; Watkins, Paul A.; Berger, Johannes; Black, Paul N.

doi:10.1074/jbc.m409598200

Cited by 132 publications

(158 citation statements)

References 55 publications

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“…Hall et al (41) showed a virtual absence of very long chain ACS activity in the skin of Fatp4 Ϫ/Ϫ mice, despite the fact that FATP1, FATP3, and FATP6 should still be present (52). These results point to a lack of FATP functional redundancy in suprabasal keratinocytes, as suggested previously by yeast complementation assays (39), and underscore the importance of FATP4. We also demonstrate an abnormal fatty acid composition of ceramides in the epidermis, consistent with data from Herrmann et al (6), indicating a decreased proportion of longer chain fatty acids and an increased proportion of shorter chain fatty acids; this fatty acid chain length composition is restored to that of control animals in the transgene-rescued mutants, suggesting that the fatty acid chain lengths of skin lipids are determined in part by FATP4 activity and are essential to normal skin function.…”

Section: Fatp4mentioning

confidence: 65%

Keratinocyte-specific Expression of Fatty Acid Transport Protein 4 Rescues the Wrinkle-free Phenotype in Slc27a4/Fatp4 Mutant Mice

Moulson

Lin

White

et al. 2007

Journal of Biological Chemistry

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FATP4 (fatty acid transport protein 4; also known as SLC27A4) is the most widely expressed member of a family of six long chain fatty acid transporters. FATP4 is highly expressed in enterocytes and has therefore been proposed to be a major importer of dietary fatty acids. Two independent mutations in Fatp4 cause mice to be born with thick, tight, shiny, "wrinklefree" skin and a defective skin barrier; they die within hours of birth from dehydration and restricted movements. In contrast, induced keratinocyte-specific deficiency of FATP4 in adult mice causes only mild skin abnormalities. Therefore, whether the loss of FATP4 from skin or a systemic gestational metabolic defect causes the severe skin defects and neonatal lethality remain important unanswered questions. To investigate the basis for the phenotype, we first generated wild-type tetraploid/mutant diploid aggregates that should lead to rescue of any abnormalities caused by loss of FATP4 from the placenta. However, the skin phenotype was not ameliorated. We then generated transgenic mice expressing exogenous FATP4 either widely or specifically in suprabasal keratinocytes, and we bred the transgenes onto the Fatp4 ؊/؊ background. Both modes of FATP4 expression led to rescue of the neonatally lethal skin defects, and the resulting mice were viable and fertile. Keratinocyte expression of an FATP4 variant with mutations in the acyl-CoA synthetase domain did not provide any degree of rescue. We conclude that expression of FATP4 with an intact acyl-CoA synthetase domain in suprabasal keratinocytes is necessary for normal skin development and that FATP4 functions in establishing the cornified envelope. Fatty acid transport proteins (FATPs)2 compose a family of transmembrane proteins that facilitate cellular long chain fatty acid uptake (1-3). The most widely expressed member of this family is FATP4 (4, 5), which is encoded by Slc27a4 (solute carrier family 27 member 4 gene). The most robust expression of FATP4 is in intestinal epithelial cells (5), but its broad expression pattern is suggestive of functions in many organs.Surprisingly, the "wrinkle-free" phenotype we discovered in mice with a spontaneous mutation in Slc27a4 (Slc27a4 wrfr ) and the identical phenotype of mice with a targeted Slc27a4 mutation (Slc27a4) indicate critical roles for FATP4 in skin and hair development (6, 7). For these mutations, which both affect exon 3, homozygotes are born with tight, thick, shiny skin and a defective skin barrier; they die shortly after birth because of restricted movements and dehydration. These defects are reminiscent of human restrictive dermopathy, but this disease has recently been linked to mutations in zinc metalloproteinase STE24 (8 -10). Interestingly, deletion of Slc27a4 exons 2 and 3 (the first two coding exons; Slc27a4 tm1Asta ) results in embryonic lethality prior to embryonic day 9.5 (11). The reason for the striking difference in phenotypes remains unknown, but it may involve a partially functional truncated protein in the first two mutants or early ...

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Section: Fatp4mentioning

confidence: 65%

Keratinocyte-specific Expression of Fatty Acid Transport Protein 4 Rescues the Wrinkle-free Phenotype in Slc27a4/Fatp4 Mutant Mice

Moulson

Lin

White

et al. 2007

Journal of Biological Chemistry

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“…Purified FATP1 and FATP4 activate a wide range of FAs and show no preference for very-long-chain FAs [7,27]. Additionally, when overexpressed in a genetically modified yeast strain with low ACS activity, all FATPs with the exception of FATP5 are able to increase ACS activity using different long-chain and verylong-chain substrates [28]. The same study shows that rates of FA uptake and ACS activity are often dissociated.…”

Section: Role Of Acyl-coa Synthetases In Modulating Fa Uptakementioning

confidence: 79%

Section: Role Of Acyl-coa Synthetases In Fa Channelingmentioning

confidence: 99%

“…Similarly, complementation studies of ACS-deficient E. coli showed that each of the 5 rat ACSL isoforms differs in its ability to channel FA into specific pathways like phospholipid synthesis and β-oxidation [32]. The ACSL and FATP isoforms also differ in their ability to complement FA uptake and activation in mutated yeast strains that lack ACS activity [28,33].In cultured mammalian cells, gain-of-function and loss-of-function studies also strongly suggest that the different ACSL isoforms channel FA into specific metabolic pathways, consistent with differences in their subcellular locations and substrate preferences. In rat hepatocytes and human fibroblasts, for example, triacsin C, a competitive inhibitor of ACSL1, ACSL3, and ACSL4 [34,35], preferentially decreases [1-14 C]oleic acid incorporation into TAG relative to other glycerolipids and oxidation products [36,37].…”

mentioning

confidence: 99%

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Long-Chain Acyl-Coa Synthetases And Fatty Acid Channeling

2007

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Thirteen homologous proteins comprise the long-chain acyl-CoA synthetase (ACSL), fatty acid transport protein (FATP), and bubblegum (ACSBG) subfamilies that activate long-chain and verylong-chain fatty acids to form acyl-CoAs. Gain-and loss-of-function studies show marked differences in the ability of these enzymes to channel fatty acids into different pathways of complex lipid synthesis. Further, the ability of the ACSLs and FATPs to enhance cellular FA uptake does not always require these proteins to be present on the plasma membrane; instead, FA uptake can be increased by enhancing its conversion to acyl-CoA and its metabolism in downstream pathways. Since altered fatty acid metabolism is a hallmark of numerous metabolic diseases and pathological conditions, the ACSL, FATP and ACSBG isoforms are likely to play important roles in disease etiology. A family of acyl-CoA synthetases activates intracellular long-chain fatty acidsBefore a fatty acid (FA) from an exogenous or endogenous source can enter any metabolic pathway with the exception of eicosanoid metabolism, it must first be activated to form an acyl-CoA. This activation step is catalyzed by acyl-CoA synthetase (ACS) via a two-step reaction: 1) the formation of an intermediate fatty acyl-AMP with the release of pyrophosphate, and 2) the formation of a fatty acyl-CoA with the release of AMP.The ACS family is comprised of at least 25 members [1]. Although overlap exists, ACS family members are broadly classified by their substrate specificities for FAs of varying chain length. This review will focus on the three subfamilies of ACS enzymes that activate long-chain and/ or very-long-chain saturated and unsaturated FAs, long-chain ACSs (ACSL), very-long-chain ACSs (FATP), and bubblegum (ACSBG) isoforms [2].The ACSL, FATP and ACSBG families include multiple isoforms, each encoded by a separate gene (Tables 1, 2). Additionally, splice variants of ACSL isoforms have been identified in both humans and rodents [3]. ACS enzymes share significant amino acid sequence similarity, particularly in two highly conserved regions, a putative ATP-AMP signature motif for ATP binding and a motif for FA binding [4]. Despite these similarities, purified ACSL and FATP isoforms and their splice variants show distinct enzyme kinetics, differences in sensitivity to inhibitors ( Role of acyl-CoA synthetases in FA channelingThe existence of 13 ACSL, FATP and ACSBG isoforms that all activate long-chain FA has suggested that each has an independent role in channeling FA within cells. Unique roles for ACS isoforms were first identified in studies of Saccharomyces cerevisiae mutants that lacked the ACS isoforms Faa1 and Faa4, and were unable to use exogenously provided fatty acids [31]. Similarly, complementation studies of ACS-deficient E. coli showed that each of the 5 rat ACSL isoforms differs in its ability to channel FA into specific pathways like phospholipid synthesis and β-oxidation [32]. The ACSL and FATP isoforms also differ in their ability to complement FA uptake and a...

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“…The lack of differences in the amount of tracer entering brain aqueous fraction, which represents products of β-oxidation (46,(67)(68)(69) (Figure 3), indicates that α-synuclein does not impact the mitochondrial pool relative to the endoplasmic reticulum pool, similar to the effect observed using 16:0 (29). Moreover, fatty acid transport protein (FATP) is associated with plasma membrane and exhibits both fatty acid transport and acyl-CoA synthetase activities (90)(91)(92) and FATP-4 is expressed in the brain (93). The potential involvement of this enzyme in acyl-CoA formation may account for the lack of differences between the groups in whole brain homogenate acyl-CoA activity and the similar incorporation coefficients for 20:4n-6 from the plasma into the total brain acyl-CoA pool.…”

Section: Discussionmentioning

confidence: 99%

Acyl-CoA Synthetase Activity Links Wild-Type but Not Mutant α-Synuclein to Brain Arachidonate Metabolism

et al. 2006

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Because α-synuclein (Snca) has a role in brain lipid metabolism, we determined the impact that the loss of α-synuclein had on brain arachidonic acid (20:4n-6) metabolism in vivo using Snca -/-mice. We measured [1-14 C]20:4n-6 incorporation and turnover kinetics in brain phospholipids using an established steady-state kinetic model. Liver was used as a negative control and no changes were observed between groups. In Snca -/-brains, there was a marked reduction in 20:4n-6-CoA mass and in microsomal acyl-CoA synthetases (Acsl) activity toward 20:4n-6. Microsomal Acsl activity was completely restored after the addition of exogenous wt mouse or human α-synuclein, but not by A30P, E46K, and A53T forms of α-synuclein. Acsl and acyl-CoA hydrolase expression was not different between groups. The incorporation and turnover of 20:4n-6 into brain phospholipid pools was markedly reduced. The dilution coefficient lambda, which indicates 20:4n-6 recycling between the acyl-CoA pool and brain phospholipids, was increased 3.3-fold, indicating more 20:4n-6 was entering the 20:4n-6-CoA pool from the plasma relative to that being recycled from the phospholipids. This is consistent with the reduction in Acsl activity observed in the Snca -/-mice. Using titration microcalorimetry, we determined that α-synuclein bound free 20:4n-6 (K d of 3.7 μM), but did not bind 20:4n-6-CoA. These data suggest α-synuclein is involved in substrate presentation to Acsl rather than product removal. In summary, our data demonstrate that α-synuclein has a major role in brain 20:4n-6 metabolism through its modulation of endoplasmic reticulum localized acyl-CoA synthetase activity, although mutants forms of α-synuclein fail to restore this activity. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript α-Synuclein is a 140 amino acid soluble protein that is highly expressed in the central nervous system (1,2) and is abundant in presynaptic terminals of neurons (1,(3)(4)(5). α-Synuclein is also found in other regions of neurons, in astrocytes, and in oligodendroglia (6-11). Overexpression of and mutations in α-synuclein are associated with early onset Parkinson's disease (12)(13)(14)(15) and other neurodegenerative diseases (16)(17)(18)(19)(20). Despite this association with neurodegenerative diseases, the physiological function of this protein remains unclear.Several lines of evidence suggest that α-synuclein can influence brain lipid metabolism. It has structural similarities to class A2 apolipoproteins (21,22) and to fatty acid binding proteins (23), suggesting that α-synuclein may alter intracellular lipid trafficking, the regulation of lipid metabolism, and may act to stabilize lipid membranes. α-Synuclein binds to small phospholipid vesicles (22,24,25) and to brain vesicles (26). Consistent with this binding, the lack of α-synuclein decreases the resting/reserve pool of synaptic vesicles (27,28). Although the direct binding of fatty acids is controversial (23,29), recent studies indicate a strong potential for an important ...

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Comparative Biochemical Studies of the Murine Fatty Acid Transport Proteins (FATP) Expressed in Yeast

Cited by 132 publications

References 55 publications

Keratinocyte-specific Expression of Fatty Acid Transport Protein 4 Rescues the Wrinkle-free Phenotype in Slc27a4/Fatp4 Mutant Mice

Keratinocyte-specific Expression of Fatty Acid Transport Protein 4 Rescues the Wrinkle-free Phenotype in Slc27a4/Fatp4 Mutant Mice

Long-Chain Acyl-Coa Synthetases And Fatty Acid Channeling

Acyl-CoA Synthetase Activity Links Wild-Type but Not Mutant α-Synuclein to Brain Arachidonate Metabolism

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