The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform

James R Woodgett - One of the best experts on this subject based on the ideXlab platform.

  • identification of multifunctional ATP Citrate Lyase kinase as the α isoform of glycogen synthase kinase 3
    Biochemical Journal, 1992
    Co-Authors: K Hughes, W B Benjamin, S Ramakrishna, James R Woodgett
    Abstract:

    Multifunctional ATP-Citrate Lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-Citrate Lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

  • Identification of multifunctional ATP-Citrate Lyase kinase as the alpha-isoform of glycogen synthase kinase-3.
    The Biochemical journal, 1992
    Co-Authors: K Hughes, W B Benjamin, S Ramakrishna, James R Woodgett
    Abstract:

    Multifunctional ATP-Citrate Lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-Citrate Lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

K Hughes - One of the best experts on this subject based on the ideXlab platform.

  • identification of multifunctional ATP Citrate Lyase kinase as the α isoform of glycogen synthase kinase 3
    Biochemical Journal, 1992
    Co-Authors: K Hughes, W B Benjamin, S Ramakrishna, James R Woodgett
    Abstract:

    Multifunctional ATP-Citrate Lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-Citrate Lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

  • Identification of multifunctional ATP-Citrate Lyase kinase as the alpha-isoform of glycogen synthase kinase-3.
    The Biochemical journal, 1992
    Co-Authors: K Hughes, W B Benjamin, S Ramakrishna, James R Woodgett
    Abstract:

    Multifunctional ATP-Citrate Lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-Citrate Lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

S Ramakrishna - One of the best experts on this subject based on the ideXlab platform.

  • Identification of multifunctional ATP-Citrate Lyase kinase as the alpha-isoform of glycogen synthase kinase-3.
    The Biochemical journal, 1992
    Co-Authors: K Hughes, W B Benjamin, S Ramakrishna, James R Woodgett
    Abstract:

    Multifunctional ATP-Citrate Lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-Citrate Lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

  • identification of multifunctional ATP Citrate Lyase kinase as the α isoform of glycogen synthase kinase 3
    Biochemical Journal, 1992
    Co-Authors: K Hughes, W B Benjamin, S Ramakrishna, James R Woodgett
    Abstract:

    Multifunctional ATP-Citrate Lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-Citrate Lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

  • An insulin-sensitive cytosolic protein kinase accounts for the regulation of ATP Citrate-Lyase phosphorylation
    Biochemical Journal, 1990
    Co-Authors: Kin-tak Yu, W B Benjamin, S Ramakrishna, Nazer Khalaf, Michael P. Czech
    Abstract:

    Purified rat liver ATP Citrate-Lyase is phosphorylated on serine residues by an insulin-stimulated cytosolic kinase activity partially purified from rat adipocytes [Yu, Khalaf & Czech (1987) J. Biol. Chem. 262, 16677-16685]. The Km for Lyase phosphorylation by this hormone-sensitive kinase activity is approx. 3 microM. Two-dimensional tryptic-peptide mapping of the 32P-labelled Lyase reveals that the kinase-catalysed phosphorylation occurs primarily on a specific peptide. In intact 32P-labelled adipocytes, insulin enhances the serine phosphorylation of ATP Citrate-Lyase by 2-3-fold. Tryptic digestion of the 32P-labelled Lyase immunopurified from insulin-treated adipocytes also yields one major phosphopeptide. 32P-labelled Lyase tryptic peptides derived from labelling experiments in vitro and in vivo exhibit identical electrophoretic and chromatographic migration profiles. Furthermore, radio-sequencing of the phosphopeptide from Lyase 32P-labelled in vitro indicates that serine-3 from the N-terminus is phosphorylated by the insulin-stimulated cytosolic kinase, in agreement with previous studies on the position of the phosphoserine residue in ATP Citrate-Lyase isolated from insulin-treated cells. Taken together, the similarity in site-specific phosphorylation of ATP Citrate-Lyase from insulin-treated adipocytes to that catalysed by the hormone-activated cytosolic kinase in vitro strongly suggests that this kinase mediates insulin action on Lyase phosphorylation in intact cells.

W B Benjamin - One of the best experts on this subject based on the ideXlab platform.

  • Identification of multifunctional ATP-Citrate Lyase kinase as the alpha-isoform of glycogen synthase kinase-3.
    The Biochemical journal, 1992
    Co-Authors: K Hughes, W B Benjamin, S Ramakrishna, James R Woodgett
    Abstract:

    Multifunctional ATP-Citrate Lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-Citrate Lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

  • identification of multifunctional ATP Citrate Lyase kinase as the α isoform of glycogen synthase kinase 3
    Biochemical Journal, 1992
    Co-Authors: K Hughes, W B Benjamin, S Ramakrishna, James R Woodgett
    Abstract:

    Multifunctional ATP-Citrate Lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-Citrate Lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

  • An insulin-sensitive cytosolic protein kinase accounts for the regulation of ATP Citrate-Lyase phosphorylation
    Biochemical Journal, 1990
    Co-Authors: Kin-tak Yu, W B Benjamin, S Ramakrishna, Nazer Khalaf, Michael P. Czech
    Abstract:

    Purified rat liver ATP Citrate-Lyase is phosphorylated on serine residues by an insulin-stimulated cytosolic kinase activity partially purified from rat adipocytes [Yu, Khalaf & Czech (1987) J. Biol. Chem. 262, 16677-16685]. The Km for Lyase phosphorylation by this hormone-sensitive kinase activity is approx. 3 microM. Two-dimensional tryptic-peptide mapping of the 32P-labelled Lyase reveals that the kinase-catalysed phosphorylation occurs primarily on a specific peptide. In intact 32P-labelled adipocytes, insulin enhances the serine phosphorylation of ATP Citrate-Lyase by 2-3-fold. Tryptic digestion of the 32P-labelled Lyase immunopurified from insulin-treated adipocytes also yields one major phosphopeptide. 32P-labelled Lyase tryptic peptides derived from labelling experiments in vitro and in vivo exhibit identical electrophoretic and chromatographic migration profiles. Furthermore, radio-sequencing of the phosphopeptide from Lyase 32P-labelled in vitro indicates that serine-3 from the N-terminus is phosphorylated by the insulin-stimulated cytosolic kinase, in agreement with previous studies on the position of the phosphoserine residue in ATP Citrate-Lyase isolated from insulin-treated cells. Taken together, the similarity in site-specific phosphorylation of ATP Citrate-Lyase from insulin-treated adipocytes to that catalysed by the hormone-activated cytosolic kinase in vitro strongly suggests that this kinase mediates insulin action on Lyase phosphorylation in intact cells.

Sahngwook Park - One of the best experts on this subject based on the ideXlab platform.

  • Cloning and identification of exon-intron organization of the rat ATP-Citrate Lyase gene
    Biochimica et Biophysica Acta, 1996
    Co-Authors: Young-ah Moon, Sahngwook Park
    Abstract:

    Abstract The rat ATP-Citrate Lyase gene was cloned and the complete exon-intron organization of the gene has been identified. The ATP-Citrate Lyase gene, spanning about 55 kb, is divided into 29 exons that range in size from 30 to 986 base pairs. The sequences bordering the splice site junctions universally follow the GT/AG rule. Reverse transcription-polymerase chain reaction showed two forms of ACL mRNA; the one containing complete exons and the other lacking exon 14 were found in the brain, kidney, mammary gland, lung and liver. Also, the restriction fragment length polymorphisms were observed at intron 10 and intron 1 I regions.

  • Organization of the 5' region of the rat ATP Citrate Lyase gene.
    Biochemical Journal, 1994
    Co-Authors: Sahngwook Park, Young-ah Moon
    Abstract:

    A genomic clone, encompassing the 5′ flanking region and the first seven exons of rat ATP Citrate Lyase gene, was isolated from a rat genomic library and sequenced. Primer-extension analysis showed that mRNA is transcribed at 4407 nucleotides upstream from the translation start site. Primer-extension analysis and sequencing of ATP Citrate Lyase cDNA amplified by PCR showed that the promoter used for transcription is identical in mammary gland, lung, liver, brain and kidney. Southern-blot analysis showed that the ATP Citrate Lyase gene exists as a single copy. The 5′ flanking region contains several consensus sequences defined as promoter elements. These include a CAAT box and Sp1-binding sites. However, a TATA box lacks this promoter. The expression of the chloramphenicol acetyltransferase gene was induced by the 5‘ flanking region (-2370 to -1) in the CHO cell line. The 5′ flanking region also contains several sequence elements that may be involved in the transcriptional regulation of the gene.

  • Induction of hepatic ATP-Citrate Lyase by insulin in diabetic rat--effects of insulin on the contents of enzyme and its mRNA in cytosol, and the transcriptional activity in nuclei.
    Yonsei Medical Journal, 1994
    Co-Authors: Sahngwook Park, Suk Kuy Whang
    Abstract:

    The effects of insulin on ATP-Citrate Lyase, its mRNA in cytosol, and the transcriptional activity in nuclei of diabetic rat liver were studied. Experimental diabetes was induced by an intraperitoneal injection of streptozotocin, and livers were removed from rats at 0, 1, 3, 6, 16, and 72 hours after the administration of insulin. ATP-Citrate Lyase began to increase at 16 hours, and continuously increased until 72 hours. The amount of mRNA encoding ATP-Citrate Lyase increased abruptly at 16 hours, then decreased to near basal level in 72 hours. No change in the transcription rate was observed until 3 hours after insulin administration. However, the activity increased 4-fold at 6 hours and 7-fold at 16 hours, 16-fold at 6 hours and 28-fold at 16 hours when pGACL1 and pGACL2 were used as probes, respectively, preceding the increase in the amounts of mRNA and the enzyme. It is suggested that the increase in the amount of ATP-Citrate Lyase by insulin is primarily due to the increase in the transcriptional activity of the gene in nuclei, which results in the subsequent increase in the amount of mRNA for the biosynthesis of ATP-Citrate Lyase in cytosol.

  • regulation of ATP Citrate Lyase at transcriptional and post transcriptional levels in rat liver
    Biochemical and Biophysical Research Communications, 1992
    Co-Authors: Sahngwook Park
    Abstract:

    The amounts of ATP-Citrate Lyase in liver cytosol began to increase at 12 hours after refeeding a high-carbohydrate diet and further increased until 48 hours. The amounts of the ATP-Citrate Lyase mRNA began to increase at 6 hours and reached to a maximum level at 12 hours, followed by decrease to a very low level until 48 hours. The elevated amount of the ATP-Citrate Lyase mRNA reflected on the increase of ATP-Citrate Lyase content in the first 24 hours, but these two parameters were not paralleled thereafter. The transcriptional activity of ATP-Citrate Lyase gene in nuclei of rat liver began to increase at 4 hours and further increased to reach a maximum level of 24 fold at 12 hours, maintaining a high level of 17 fold until 48 hours. The elevation of transcriptional activity of ATP-Citrate Lyase gene preceded the increase of ATP-Citrate Lyase mRNA content in the liver cytosol by 2 hours, and its increasing pattern was similar to changes of mRNA content until 12 hours. However, while the transcriptional activity remained at a high level until 48 hours, the ATP-Citrate Lyase mRNA concentration in the cytosol decreased after 12 hours.