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Ermann J, Chung CD, Fathman CG. Scratching the (T cell) surface. Genome Biol 2004; 5:202. [PMID: 14709166 PMCID: PMC395726 DOI: 10.1186/gb-2003-5-1-202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Using a genome-scale approach to study transcription levels in a human CD8+ T-cell clone, a recent study has suggested that the repertoire of molecules on the surface of T cells is close to being completely characterized. Using a genome-scale approach to study transcription levels in a human CD8+ T-cell clone, a recent study has suggested that the repertoire of molecules on the surface of T cells is close to being completely characterized.
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Affiliation(s)
- Joerg Ermann
- Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
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2
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Soares L, Seroogy C, Skrenta H, Anandasabapathy N, Lovelace P, Chung CD, Engleman E, Fathman CG. Two isoforms of otubain 1 regulate T cell anergy via GRAIL. Nat Immunol 2003; 5:45-54. [PMID: 14661020 DOI: 10.1038/ni1017] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2003] [Accepted: 10/28/2003] [Indexed: 11/08/2022]
Abstract
The active ubiquitin E3 ligase GRAIL is crucial in the induction of CD4 T cell anergy. Here we show that GRAIL is associated with and regulated by two isoforms of the ubiquitin-specific protease otubain 1. In lethally irradiated mice reconstituted with bone marrow cells from T cell receptor-transgenic mice retrovirally transduced to express the genes encoding these proteases, otubain 1-expressing cells contained negligible amounts of endogenous GRAIL, proliferated well and produced large amounts of interleukin 2 after antigenic stimulation. In contrast, cells expressing the alternatively spliced isoform, otubain 1 alternative reading frame 1, contained large amounts of endogenous GRAIL and were functionally anergic, and they proliferated poorly and produced undetectable interleukin 2 when stimulated in a similar way. Thus, these two proteins have opposing epistatic functions in controlling the stability of GRAIL expression and the resultant anergy phenotype in T cells.
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Affiliation(s)
- Luis Soares
- Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California 94305, USA
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3
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Chung CD, Kuo F, Kumer J, Motani AS, Lawrence CE, Henderson WR, Venkataraman C. CCR8 is not essential for the development of inflammation in a mouse model of allergic airway disease. J Immunol 2003; 170:581-7. [PMID: 12496446 DOI: 10.4049/jimmunol.170.1.581] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Chemokine receptors play an important role in the trafficking of various immune cell types to sites of inflammation. Several chemokine receptors are differentially expressed in Th1 and Th2 effector populations. Th2 cells selectively express CCR3, CCR4, and CCR8, which could direct their trafficking to sites of allergic inflammation. Additionally, increased expression of the CCR8 ligand, TCA-3, has been detected in affected lungs in a mouse model of asthma. In this study, CCR8-deficient mice were generated to address the biological role of CCR8 in a model of allergic airway disease. Using two different protocols of allergen challenge, we demonstrate that absence of CCR8 does not affect the development of pulmonary eosinophilia and Th2 cytokine responses. In addition, administration of anti-TCA-3-neutralizing Ab during allergen sensitization and rechallenge failed to inhibit airway allergic inflammation. These results suggest that CCR8 does not play an essential role in the pathogenesis of inflammation in this mouse model of allergic airway disease.
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MESH Headings
- Animals
- Antibodies, Blocking/administration & dosage
- Antigens/administration & dosage
- Antigens/immunology
- Bronchoalveolar Lavage Fluid/chemistry
- Bronchoalveolar Lavage Fluid/immunology
- Cell Migration Inhibition
- Chemokine CCL1
- Chemokines, CC/metabolism
- Crosses, Genetic
- Cytokines/antagonists & inhibitors
- Cytokines/immunology
- Disease Models, Animal
- Dose-Response Relationship, Immunologic
- Drug Administration Schedule
- Female
- Inflammation/genetics
- Inflammation/immunology
- Inflammation/pathology
- Injections, Intraperitoneal
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Ovalbumin/administration & dosage
- Ovalbumin/immunology
- Receptors, CCR8
- Receptors, Chemokine/biosynthesis
- Receptors, Chemokine/deficiency
- Receptors, Chemokine/genetics
- Receptors, Chemokine/physiology
- Respiratory Hypersensitivity/genetics
- Respiratory Hypersensitivity/immunology
- Respiratory Hypersensitivity/pathology
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Affiliation(s)
- Chan D Chung
- Tularik, Inc., South San Francisco, CA 94080, USA
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4
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Miceli MC, Moran M, Chung CD, Patel VP, Low T, Zinnanti W. Co-stimulation and counter-stimulation: lipid raft clustering controls TCR signaling and functional outcomes. Semin Immunol 2001; 13:115-28. [PMID: 11308295 DOI: 10.1006/smim.2000.0303] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
T cell receptor (TCR) antigen recognition induces the formation of a specialized 'immunological synapse' at the T cell : antigen presenting cell (APC) junction. This junction is generated by the recruitment and exclusion of particular proteins from the contact area and is required for T cell activation. We and others have hypothesized that lipid raft/non-raft partitioning provides a molecular basis for protein sorting which organizes the TCR, co-stimulators, signal transducers and the actin cytoskeleton at the T cell : APC interface. Here we discuss the emerging paradigm that co-stimulators induce the directional transport and clustering of lipid rafts at the T cell : APC interface, thus generating platform(s) specialized for processive and sustained TCR signal transduction and T cell activation. We also discuss recent data implicating the involvement of 'counter-stimulators' and other negative regulators which prevent optimal raft clustering at the TCR contact site and, thus, facilitate T cell inactivation and tolerance induction.
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Affiliation(s)
- M C Miceli
- Department of Microbiology, Immunology and Molecular Genetics, UCLA School of Medicine, Los Angeles, CA 90095-1570, USA.
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5
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Chung CD, Patel VP, Moran M, Lewis LA, Miceli MC. Galectin-1 induces partial TCR zeta-chain phosphorylation and antagonizes processive TCR signal transduction. J Immunol 2000; 165:3722-9. [PMID: 11034377 DOI: 10.4049/jimmunol.165.7.3722] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Galectin-1 is an endogenous lectin with known T cell immunoregulatory activity, though the molecular basis by which galectin-1 influences Ag specific T cell responses has not been elucidated. Here, we characterize the ability of galectin-1 to modulate TCR signals and responses by T cells with well defined hierarchies of threshold requirements for signaling distinct functional responses. We demonstrate that galectin-1 antagonizes TCR responses known to require costimulation and processive protein tyrosine phosphorylation, such as IL-2 production, but is permissive for TCR responses that only require partial TCR signals, such as IFN-gamma production, CD69 up-regulation, and apoptosis. Galectin-1 binding alone or together with Ag stimulation induces partial phosphorylation of TCR-zeta and the generation of inhibitory pp21zeta. Galectin-1 antagonizes Ag induced signals and TCR/costimulator dependent lipid raft clustering at the TCR contact site. We propose that galectin-1 functions as a T cell "counterstimulator" to limit required protein segregation and lipid raft reorganization at the TCR contact site and, thus, processive and sustained TCR signal transduction. These findings support the concept that TCR antagonism can arise from the generation of an inhibitory pp21zeta-based TCR signaling complex. Moreover, they demonstrate that TCR antagonism can result from T cell interactions with a ligand other than peptide/MHC.
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Affiliation(s)
- C D Chung
- Department of Biological Chemistry, University of California School of Medicine, Los Angeles 90095, USA
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6
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Liu B, Liao J, Rao X, Kushner SA, Chung CD, Chang DD, Shuai K. Inhibition of Stat1-mediated gene activation by PIAS1. Proc Natl Acad Sci U S A 1998; 95:10626-31. [PMID: 9724754 PMCID: PMC27945 DOI: 10.1073/pnas.95.18.10626] [Citation(s) in RCA: 550] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/1998] [Accepted: 07/06/1998] [Indexed: 01/14/2023] Open
Abstract
STAT (signal transducer and activator of transcription) proteins are latent cytoplasmic transcription factors that become activated by tyrosine phosphorylation in response to cytokine stimulation. Tyrosine phosphorylated STATs dimerize and translocate into the nucleus to activate specific genes. Different members of the STAT protein family have distinct functions in cytokine signaling. Biochemical and genetic analysis has demonstrated that Stat1 is essential for gene activation in response to interferon stimulation. Although progress has been made toward understanding STAT activation, little is known about how STAT signals are down-regulated. We report here the isolation of a family of PIAS (protein inhibitor of activated STAT) proteins. PIAS1, but not other PIAS proteins, blocked the DNA binding activity of Stat1 and inhibited Stat1-mediated gene activation in response to interferon. Coimmunoprecipitation analysis showed that PIAS1 was associated with Stat1 but not Stat2 or Stat3 after ligand stimulation. The in vivo PIAS1-Stat1 interaction requires phosphorylation of Stat1 on Tyr-701. These results identify PIAS1 as a specific inhibitor of Stat1-mediated gene activation and suggest that there may exist a specific PIAS inhibitor in every STAT signaling pathway.
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Affiliation(s)
- B Liu
- Division of Hematology-Oncology, Department of Medicine, Immunology, and Molecular Genetics, University of California, Los Angeles, CA 90095, USA
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7
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Abstract
The signal transducer and activator of transcription-3 (Stat3) protein is activated by the interleukin 6 (IL-6) family of cytokines, epidermal growth factor, and leptin. A protein named PIAS3 (protein inhibitor of activated STAT) that binds to Stat3 was isolated and characterized. The association of PIAS3 with Stat3 in vivo was only observed in cells stimulated with ligands that cause the activation of Stat3. PIAS3 blocked the DNA-binding activity of Stat3 and inhibited Stat3-mediated gene activation. Although Stat1 is also phosphorylated in response to IL-6, PIAS3 did not interact with Stat1 or affect its DNA-binding or transcriptional activity. The results indicate that PIAS3 is a specific inhibitor of Stat3.
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Affiliation(s)
- C D Chung
- Department of Biological Chemistry, University of California, Los Angeles, CA 90095, USA
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8
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Lewis LA, Chung CD, Chen J, Parnes JR, Moran M, Patel VP, Miceli MC. The Lck SH2 phosphotyrosine binding site is critical for efficient TCR-induced processive tyrosine phosphorylation of the zeta-chain and IL-2 production. J Immunol 1997; 159:2292-300. [PMID: 9278318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The lymphocyte-specific tyrosine kinase Lck is essential for TCR-mediated signal transduction. This is in part due to its enzymatic activity as a tyrosine kinase responsible for TCR-induced tyrosine phosphorylation of zeta and CD3 receptor subunits. In addition to its catalytic domain, the Lck protein contains SH3 and SH2 domains capable of associating with other signaling molecules. It has been proposed that phosphotyrosine binding by the Lck SH2 domain may enhance substrate tyrosine phosphorylation by facilitating the processive phosphorylation of multiple sites within the TCR complex. Alternatively or additionally, it may function in adapter activity for facilitating required protein-protein interactions. Previous experiments demonstrate that overexpression of a constitutively activated form of Lck (F505) in the BI-141 T cell hybridoma leads to the Lck kinase activity-dependent enhancement of TCR-mediated signals. Here we demonstrate that mutation of amino acids important for SH2 phosphotyrosine binding significantly compromises the ability of F505 to enhance TCR-mediated protein tyrosine phosphorylation and Ag-induced IL-2 production in BI-141. Examination of the effects of TCR-regulated phosphorylation of the Lck substrate zeta provides in vivo evidence for a role for the Lck SH2 domain in the processive phosphorylation of a multiply phosphorylated substrate.
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Affiliation(s)
- L A Lewis
- Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, 90095, USA
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9
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Lewis LA, Chung CD, Chen J, Parnes JR, Moran M, Patel VP, Miceli MC. The Lck SH2 phosphotyrosine binding site is critical for efficient TCR-induced processive tyrosine phosphorylation of the zeta-chain and IL-2 production. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.159.5.2292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The lymphocyte-specific tyrosine kinase Lck is essential for TCR-mediated signal transduction. This is in part due to its enzymatic activity as a tyrosine kinase responsible for TCR-induced tyrosine phosphorylation of zeta and CD3 receptor subunits. In addition to its catalytic domain, the Lck protein contains SH3 and SH2 domains capable of associating with other signaling molecules. It has been proposed that phosphotyrosine binding by the Lck SH2 domain may enhance substrate tyrosine phosphorylation by facilitating the processive phosphorylation of multiple sites within the TCR complex. Alternatively or additionally, it may function in adapter activity for facilitating required protein-protein interactions. Previous experiments demonstrate that overexpression of a constitutively activated form of Lck (F505) in the BI-141 T cell hybridoma leads to the Lck kinase activity-dependent enhancement of TCR-mediated signals. Here we demonstrate that mutation of amino acids important for SH2 phosphotyrosine binding significantly compromises the ability of F505 to enhance TCR-mediated protein tyrosine phosphorylation and Ag-induced IL-2 production in BI-141. Examination of the effects of TCR-regulated phosphorylation of the Lck substrate zeta provides in vivo evidence for a role for the Lck SH2 domain in the processive phosphorylation of a multiply phosphorylated substrate.
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Affiliation(s)
- L A Lewis
- Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, 90095, USA
| | - C D Chung
- Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, 90095, USA
| | - J Chen
- Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, 90095, USA
| | - J R Parnes
- Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, 90095, USA
| | - M Moran
- Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, 90095, USA
| | - V P Patel
- Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, 90095, USA
| | - M C Miceli
- Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, 90095, USA
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10
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Chung CD, Lewis LA, Miceli MC. T cell antigen receptor-induced IL-2 production and apoptosis have different requirements for Lck activities. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.159.4.1758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The T cell hybridoma BI-141 has been previously used to dissect the roles of Lck in Ag-induced IL-2 production. Here we demonstrate that BI-141 undergoes apoptosis in response to TCR stimulation using Ag or anti-TCR Abs. Using a panel of BI-141 transfectants expressing constitutively activated Lck (F505) or phosphotyrosine-binding (K154F505 and C156F505) or kinase-impaired (R273F505) mutants, we assess the relative requirements for Lck in TCR-mediated IL-2 production and apoptosis. While BI-141 transfectants expressing F505 are dramatically enhanced in their ability to produce IL-2 in response to Ag relative to K154F505-, C156F505-, or R273F505-expressing transfectants, no differences between these transfectants are observed in their ability to undergo TCR-induced apoptosis. TCR-induced Fas ligand (FasL) expression is demonstrated to be dependent on Lck SH2 and kinase activities, although FasL expression cannot be correlated with apoptosis. Low levels of Fas are constitutively expressed at equal levels on transfectants and are not increased in response to TCR ligation. Together, these data indicate that TCR-induced apoptosis in BI-141 is regulated through a mechanism(s) distinct from the Lck-induced expression of Fas, FasL, or IL-2 production. This TCR signal may be independent of Lck kinase and SH2 activities, or may require lower threshold activity. The identification of differential requirements for particular T cell functions is crucial to understanding how TCR engagement affects downstream T cell functions and may aid in the rational design of therapeutics aimed at specifically modulating particular T cell responses.
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Affiliation(s)
- C D Chung
- Department of Microbiology and Immunology, University of California-Los Angeles School of Medicine, 90095, USA
| | - L A Lewis
- Department of Microbiology and Immunology, University of California-Los Angeles School of Medicine, 90095, USA
| | - M C Miceli
- Department of Microbiology and Immunology, University of California-Los Angeles School of Medicine, 90095, USA
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11
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Chung CD, Lewis LA, Miceli MC. T cell antigen receptor-induced IL-2 production and apoptosis have different requirements for Lck activities. J Immunol 1997; 159:1758-66. [PMID: 9257838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The T cell hybridoma BI-141 has been previously used to dissect the roles of Lck in Ag-induced IL-2 production. Here we demonstrate that BI-141 undergoes apoptosis in response to TCR stimulation using Ag or anti-TCR Abs. Using a panel of BI-141 transfectants expressing constitutively activated Lck (F505) or phosphotyrosine-binding (K154F505 and C156F505) or kinase-impaired (R273F505) mutants, we assess the relative requirements for Lck in TCR-mediated IL-2 production and apoptosis. While BI-141 transfectants expressing F505 are dramatically enhanced in their ability to produce IL-2 in response to Ag relative to K154F505-, C156F505-, or R273F505-expressing transfectants, no differences between these transfectants are observed in their ability to undergo TCR-induced apoptosis. TCR-induced Fas ligand (FasL) expression is demonstrated to be dependent on Lck SH2 and kinase activities, although FasL expression cannot be correlated with apoptosis. Low levels of Fas are constitutively expressed at equal levels on transfectants and are not increased in response to TCR ligation. Together, these data indicate that TCR-induced apoptosis in BI-141 is regulated through a mechanism(s) distinct from the Lck-induced expression of Fas, FasL, or IL-2 production. This TCR signal may be independent of Lck kinase and SH2 activities, or may require lower threshold activity. The identification of differential requirements for particular T cell functions is crucial to understanding how TCR engagement affects downstream T cell functions and may aid in the rational design of therapeutics aimed at specifically modulating particular T cell responses.
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Affiliation(s)
- C D Chung
- Department of Microbiology and Immunology, University of California-Los Angeles School of Medicine, 90095, USA
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12
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Chung CD, Bieber LL. Properties of the medium chain/long chain carnitine acyltransferase purified from rat liver microsomes. J Biol Chem 1993; 268:4519-24. [PMID: 8440734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Carnitine octanoyltransferase (COT) purified from rat liver microsomes has K0.5 values between 1.0 and 4.0 microM for saturated 6-carbon to 16-carbon length acyl-CoAs, with little differences in Vmax values. The reaction rate is linear with time in the forward direction (acyl-CoA-->acylcarnitine), but it increases with time when assayed in the reverse direction (acylcarnitine-->acyl-CoA). The K0.5 for decanoylcarnitine and CoASH are 0.3 mM for CoASH and between 1.0 and 4.0 mM for decanoylcarnitine. The kinetic data indicate that the enzyme functions in the direction of acyl-carnitine formation. It is moderately inhibited by aminocarnitine, and D-carnitine and etomoxiryl-CoA are weak inhibitors; malonyl-CoA does not inhibit the enzyme. The enzyme has little, if any, capacity to use valproylcarnitine, 3-methylglutarylcarnitine, or pivaloylcarnitine as a substrate. Polyclonal antibodies prepared against COT give a positive Western blot against the purified enzyme and against a protein in microsomes having the molecular mass of COT (53 kDA). Antimitochondrial CPT and antiperoxisomal CAT did not show appreciable cross-reactivity with purified microsomal COT. The inhibitor data, the kinetic data, the molecular masses, and the Western blotting profiles all show that the enzyme purified from rat liver microsomes is a different carnitine acyltransferase than those previously purified from other organelles.
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Affiliation(s)
- C D Chung
- Department of Biochemistry, Michigan State University, East Lansing 48824
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13
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Abstract
Heart and liver mitochondrial, as well as liver peroxisomal, carnitine acetyltransferase was purified to apparent homogeneity and some properties, primarily of heart mitochondrial carnitine acetyltransferase, were determined. Hill coefficients for propionyl-CoA are 1.0 for each of the enzymes. The molecular weight of heart mitochondrial carnitine acetyltransferase, determined by SDS-PAGE, is 62,000. It is monomeric in the presence of catalytic amounts of substrate. Polyclonal antibodies against purified rat liver peroxisomal carnitine acetyltransferase precipitate liver and heart mitochondrial and liver peroxisomal carnitine acetyltransferase, but not liver peroxisomal carnitine octanoyltransferase. Liver peroxisomes, mitochondria, and microsomes and heart mitochondria all give multiple bands on Western blotting with the antibody against carnitine acetyltransferase. Major protein bands occur at the molecular weight of carnitine acetyltransferase and at 33 to 35 kDa.
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Affiliation(s)
- C Chung
- Department of Biochemistry, Michigan State University, East Lansing 48824
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