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. 1994 Jun;14(6):4324–4332. doi: 10.1128/mcb.14.6.4324

Serum amyloid A gene expression under acute-phase conditions involves participation of inducible C/EBP-beta and C/EBP-delta and their activation by phosphorylation.

A Ray 1, B K Ray 1
PMCID: PMC358798  PMID: 8196668

Abstract

Serum amyloid A (SAA) is a plasma protein whose synthesis is markedly increased in the liver during the inflammatory process. Previous analysis of SAA promoter function implicated the involvement of the CCAAT/enhancer-binding protein (C/EBP) in controlling this process. In this study, using antibodies against three C/EBP isoforms in DNA-binding and Western blot (immunoblot) assays, we found that in response to inflammatory signals, both C/EBP-delta and C/EBP-beta are induced and that their interactions with the SAA promoter element are necessary for the increased SAA gene expression. Cotransfections of liver cells with an SAA promoter-linked reporter chloramphenicol acetyltransferase gene and murine sarcoma virus-expressed C/EBP-delta or C/EBP-beta confirm such phenomena. The increased transactivating ability in the presence of the cellular phosphatase inhibitors okadaic acid and sodium orthovanadate, coupled with the observation that dephosphorylation severely inhibits the DNA-binding ability in vitro, implicates a role of phosphorylation in the regulation of the activities of the C/EBP-delta isoform. Consistent with these findings, we have detected higher levels of DNA-binding activity of C/EBP-delta prepared from cells treated with phosphatase inhibitors. We also present evidence that C/EBP-delta is a phosphoprotein. These results suggest that C/EBP-delta is regulated by phosphorylation and, in conjunction with C/EBP-beta, is one of the major proteins responsible for the increased transcription of the SAA gene in response to inflammatory stimuli.

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  1. Akira S., Isshiki H., Sugita T., Tanabe O., Kinoshita S., Nishio Y., Nakajima T., Hirano T., Kishimoto T. A nuclear factor for IL-6 expression (NF-IL6) is a member of a C/EBP family. EMBO J. 1990 Jun;9(6):1897–1906. doi: 10.1002/j.1460-2075.1990.tb08316.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Baeuerle P. A., Baltimore D. Activation of DNA-binding activity in an apparently cytoplasmic precursor of the NF-kappa B transcription factor. Cell. 1988 Apr 22;53(2):211–217. doi: 10.1016/0092-8674(88)90382-0. [DOI] [PubMed] [Google Scholar]
  3. Baumann H., Morella K. K., Campos S. P., Cao Z., Jahreis G. P. Role of CAAT-enhancer binding protein isoforms in the cytokine regulation of acute-phase plasma protein genes. J Biol Chem. 1992 Sep 25;267(27):19744–19751. [PubMed] [Google Scholar]
  4. Blenis J. Signal transduction via the MAP kinases: proceed at your own RSK. Proc Natl Acad Sci U S A. 1993 Jul 1;90(13):5889–5892. doi: 10.1073/pnas.90.13.5889. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1006/abio.1976.9999. [DOI] [PubMed] [Google Scholar]
  6. Brown D. J., Gordon J. A. The stimulation of pp60v-src kinase activity by vanadate in intact cells accompanies a new phosphorylation state of the enzyme. J Biol Chem. 1984 Aug 10;259(15):9580–9586. [PubMed] [Google Scholar]
  7. Cao Z., Umek R. M., McKnight S. L. Regulated expression of three C/EBP isoforms during adipose conversion of 3T3-L1 cells. Genes Dev. 1991 Sep;5(9):1538–1552. doi: 10.1101/gad.5.9.1538. [DOI] [PubMed] [Google Scholar]
  8. Dignam J. D., Lebovitz R. M., Roeder R. G. Accurate transcription initiation by RNA polymerase II in a soluble extract from isolated mammalian nuclei. Nucleic Acids Res. 1983 Mar 11;11(5):1475–1489. doi: 10.1093/nar/11.5.1475. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Edbrooke M. R., Burt D. W., Cheshire J. K., Woo P. Identification of cis-acting sequences responsible for phorbol ester induction of human serum amyloid A gene expression via a nuclear factor kappaB-like transcription factor. Mol Cell Biol. 1989 May;9(5):1908–1916. doi: 10.1128/mcb.9.5.1908. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Edbrooke M. R., Foldi J., Cheshire J. K., Li F., Faulkes D. J., Woo P. Constitutive and NF-kappa B-like proteins in the regulation of the serum amyloid A gene by interleukin 1. Cytokine. 1991 Sep;3(5):380–388. doi: 10.1016/1043-4666(91)90041-b. [DOI] [PubMed] [Google Scholar]
  11. Fridovich-Keil J. L., Gudas J. M., Bryan I. B., Pardee A. B. Improved expression vectors for eukaryotic promoter/enhancer studies. Biotechniques. 1991 Nov;11(5):572–579. [PubMed] [Google Scholar]
  12. Ganapathi M. K., Rzewnicki D., Samols D., Jiang S. L., Kushner I. Effect of combinations of cytokines and hormones on synthesis of serum amyloid A and C-reactive protein in Hep 3B cells. J Immunol. 1991 Aug 15;147(4):1261–1265. [PubMed] [Google Scholar]
  13. Graham F. L., van der Eb A. J. A new technique for the assay of infectivity of human adenovirus 5 DNA. Virology. 1973 Apr;52(2):456–467. doi: 10.1016/0042-6822(73)90341-3. [DOI] [PubMed] [Google Scholar]
  14. Haystead T. A., Sim A. T., Carling D., Honnor R. C., Tsukitani Y., Cohen P., Hardie D. G. Effects of the tumour promoter okadaic acid on intracellular protein phosphorylation and metabolism. Nature. 1989 Jan 5;337(6202):78–81. doi: 10.1038/337078a0. [DOI] [PubMed] [Google Scholar]
  15. Hunter T., Karin M. The regulation of transcription by phosphorylation. Cell. 1992 Aug 7;70(3):375–387. doi: 10.1016/0092-8674(92)90162-6. [DOI] [PubMed] [Google Scholar]
  16. Husby G., Natvig J. B. A serum component related to nonimmunoglobulin amyloid protein AS, a possible precursor of the fibrils. J Clin Invest. 1974 Apr;53(4):1054–1061. doi: 10.1172/JCI107642. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Juan T. S., Wilson D. R., Wilde M. D., Darlington G. J. Participation of the transcription factor C/EBP delta in the acute-phase regulation of the human gene for complement component C3. Proc Natl Acad Sci U S A. 1993 Apr 1;90(7):2584–2588. doi: 10.1073/pnas.90.7.2584. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Kinoshita S., Akira S., Kishimoto T. A member of the C/EBP family, NF-IL6 beta, forms a heterodimer and transcriptionally synergizes with NF-IL6. Proc Natl Acad Sci U S A. 1992 Feb 15;89(4):1473–1476. doi: 10.1073/pnas.89.4.1473. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Lee Y. M., Tsai W. H., Lai M. Y., Chen D. S., Lee S. C. Induction of liver alpha-1 acid glycoprotein gene expression involves both positive and negative transcription factors. Mol Cell Biol. 1993 Jan;13(1):432–442. doi: 10.1128/mcb.13.1.432. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Li X. X., Huang J. H., Rienhoff H. Y., Jr, Liao W. S. Two adjacent C/EBP-binding sequences that participate in the cell-specific expression of the mouse serum amyloid A3 gene. Mol Cell Biol. 1990 Dec;10(12):6624–6631. doi: 10.1128/mcb.10.12.6624. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Li X. X., Liao W. S. Expression of rat serum amyloid A1 gene involves both C/EBP-like and NF kappa B-like transcription factors. J Biol Chem. 1991 Aug 15;266(23):15192–15201. [PubMed] [Google Scholar]
  22. Luckow B., Schütz G. CAT constructions with multiple unique restriction sites for the functional analysis of eukaryotic promoters and regulatory elements. Nucleic Acids Res. 1987 Jul 10;15(13):5490–5490. doi: 10.1093/nar/15.13.5490. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Metz R., Ziff E. cAMP stimulates the C/EBP-related transcription factor rNFIL-6 to trans-locate to the nucleus and induce c-fos transcription. Genes Dev. 1991 Oct;5(10):1754–1766. doi: 10.1101/gad.5.10.1754. [DOI] [PubMed] [Google Scholar]
  24. Nakajima T., Kinoshita S., Sasagawa T., Sasaki K., Naruto M., Kishimoto T., Akira S. Phosphorylation at threonine-235 by a ras-dependent mitogen-activated protein kinase cascade is essential for transcription factor NF-IL6. Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2207–2211. doi: 10.1073/pnas.90.6.2207. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Nishio Y., Isshiki H., Kishimoto T., Akira S. A nuclear factor for interleukin-6 expression (NF-IL6) and the glucocorticoid receptor synergistically activate transcription of the rat alpha 1-acid glycoprotein gene via direct protein-protein interaction. Mol Cell Biol. 1993 Mar;13(3):1854–1862. doi: 10.1128/mcb.13.3.1854. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Ratajczak T., Williams P. M., DiLorenzo D., Ringold G. M. Multiple elements within the glucocorticoid regulatory unit of the rat alpha 1-acid glycoprotein gene are recognition sites for C/EBP. J Biol Chem. 1992 Jun 5;267(16):11111–11119. [PubMed] [Google Scholar]
  27. Ray A., Ray B. K. Analysis of the promoter element of the serum amyloid A gene and its interaction with constitutive and inducible nuclear factors from rabbit liver. Gene Expr. 1993;3(2):151–162. [PMC free article] [PubMed] [Google Scholar]
  28. Ray B. K., Gao X., Ray A. Regulation of rabbit alpha 1-acid glycoprotein gene expression in acute-phase liver. Identification of inducible and constitutive proteins like CCAAT-enhancer binding protein that interact with the 5'-proximal promoter elements. Eur J Biochem. 1993 Aug 15;216(1):127–136. doi: 10.1111/j.1432-1033.1993.tb18124.x. [DOI] [PubMed] [Google Scholar]
  29. Ray B. K., Ray A. Functional NF-kappa B element in rabbit serum amyloid A gene and its role in acute phase induction. Biochem Biophys Res Commun. 1993 Jun 30;193(3):1159–1167. doi: 10.1006/bbrc.1993.1747. [DOI] [PubMed] [Google Scholar]
  30. Ray B. K., Ray A. Rabbit serum amyloid a gene: cloning, characterization and sequence analysis. Biochem Biophys Res Commun. 1991 Nov 14;180(3):1258–1264. doi: 10.1016/s0006-291x(05)81331-2. [DOI] [PubMed] [Google Scholar]
  31. Rivera V. M., Miranti C. K., Misra R. P., Ginty D. D., Chen R. H., Blenis J., Greenberg M. E. A growth factor-induced kinase phosphorylates the serum response factor at a site that regulates its DNA-binding activity. Mol Cell Biol. 1993 Oct;13(10):6260–6273. doi: 10.1128/mcb.13.10.6260. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Rosenthal C. J., Franklin E. C., Frangione B., Greenspan J. Isolation and partial characterization of SAA-an amyloid-related protein from human serum. J Immunol. 1976 May;116(5):1415–1418. [PubMed] [Google Scholar]
  33. Sadowski H. B., Shuai K., Darnell J. E., Jr, Gilman M. Z. A common nuclear signal transduction pathway activated by growth factor and cytokine receptors. Science. 1993 Sep 24;261(5129):1739–1744. doi: 10.1126/science.8397445. [DOI] [PubMed] [Google Scholar]
  34. Samuels M. L., Weber M. J., Bishop J. M., McMahon M. Conditional transformation of cells and rapid activation of the mitogen-activated protein kinase cascade by an estradiol-dependent human raf-1 protein kinase. Mol Cell Biol. 1993 Oct;13(10):6241–6252. doi: 10.1128/mcb.13.10.6241. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Stahl N., Yancopoulos G. D. The alphas, betas, and kinases of cytokine receptor complexes. Cell. 1993 Aug 27;74(4):587–590. doi: 10.1016/0092-8674(93)90506-l. [DOI] [PubMed] [Google Scholar]
  36. Wegner M., Cao Z., Rosenfeld M. G. Calcium-regulated phosphorylation within the leucine zipper of C/EBP beta. Science. 1992 Apr 17;256(5055):370–373. doi: 10.1126/science.256.5055.370. [DOI] [PubMed] [Google Scholar]
  37. Woo P., Sipe J., Dinarello C. A., Colten H. R. Structure of a human serum amyloid A gene and modulation of its expression in transfected L cells. J Biol Chem. 1987 Nov 15;262(32):15790–15795. [PubMed] [Google Scholar]

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