Skip to main content
PMC home page
Molecular and Cellular Biology logoLink to Molecular and Cellular Biology
. 1997 May;17(5):2372–2380. doi: 10.1128/mcb.17.5.2372

Transcriptional activation and transformation by FosB protein require phosphorylation of the carboxyl-terminal activation domain.

M Skinner 1, S Qu 1, C Moore 1, R Wisdom 1
PMCID: PMC232086  PMID: 9111306

Abstract

The transcription factor AP-1, composed of Fos-Jun dimers, mediates some aspects of the cellular response to growth factors. Transcriptional activation and neoplastic transformation by FosB, a member of the Fos family of proteins, require the presence of a potent C-terminal activation domain. Here we show by mutational analysis that the FosB C-terminal domain has a proline-based motif that is essential for both of these functions. Phosphopeptide mapping experiments show that the C terminus of FosB is phosphorylated within a cluster of functionally redundant serine residues that is adjacent to this proline-based motif. Mutation of these serine residues to alanine severely reduces the ability of this region to function as an activation domain and inhibits the ability of FosB protein to function as a transforming protein. Several observations suggest that the kinase responsible for phosphorylation of these sites is distinct from the mitogen-activation protein kinases and stress-activated protein kinases. Our results show that transcriptional activation and neoplastic transformation by the FosB protein are dependent on phosphorylation within the C terminus. This form of control may provide a potential mechanism of signal integration at the level of a single transcription factor.

Full Text

The Full Text of this article is available as a PDF (836.1 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Angel P., Imagawa M., Chiu R., Stein B., Imbra R. J., Rahmsdorf H. J., Jonat C., Herrlich P., Karin M. Phorbol ester-inducible genes contain a common cis element recognized by a TPA-modulated trans-acting factor. Cell. 1987 Jun 19;49(6):729–739. doi: 10.1016/0092-8674(87)90611-8. [DOI] [PubMed] [Google Scholar]
  2. Angel P., Karin M. The role of Jun, Fos and the AP-1 complex in cell-proliferation and transformation. Biochim Biophys Acta. 1991 Dec 10;1072(2-3):129–157. doi: 10.1016/0304-419x(91)90011-9. [DOI] [PubMed] [Google Scholar]
  3. Binétruy B., Smeal T., Karin M. Ha-Ras augments c-Jun activity and stimulates phosphorylation of its activation domain. Nature. 1991 May 9;351(6322):122–127. doi: 10.1038/351122a0. [DOI] [PubMed] [Google Scholar]
  4. Boyle W. J., van der Geer P., Hunter T. Phosphopeptide mapping and phosphoamino acid analysis by two-dimensional separation on thin-layer cellulose plates. Methods Enzymol. 1991;201:110–149. doi: 10.1016/0076-6879(91)01013-r. [DOI] [PubMed] [Google Scholar]
  5. Brown J. R., Ye H., Bronson R. T., Dikkes P., Greenberg M. E. A defect in nurturing in mice lacking the immediate early gene fosB. Cell. 1996 Jul 26;86(2):297–309. doi: 10.1016/s0092-8674(00)80101-4. [DOI] [PubMed] [Google Scholar]
  6. Deng T., Karin M. c-Fos transcriptional activity stimulated by H-Ras-activated protein kinase distinct from JNK and ERK. Nature. 1994 Sep 8;371(6493):171–175. doi: 10.1038/371171a0. [DOI] [PubMed] [Google Scholar]
  7. Dérijard B., Hibi M., Wu I. H., Barrett T., Su B., Deng T., Karin M., Davis R. J. JNK1: a protein kinase stimulated by UV light and Ha-Ras that binds and phosphorylates the c-Jun activation domain. Cell. 1994 Mar 25;76(6):1025–1037. doi: 10.1016/0092-8674(94)90380-8. [DOI] [PubMed] [Google Scholar]
  8. Gille H., Sharrocks A. D., Shaw P. E. Phosphorylation of transcription factor p62TCF by MAP kinase stimulates ternary complex formation at c-fos promoter. Nature. 1992 Jul 30;358(6385):414–417. doi: 10.1038/358414a0. [DOI] [PubMed] [Google Scholar]
  9. Gille H., Strahl T., Shaw P. E. Activation of ternary complex factor Elk-1 by stress-activated protein kinases. Curr Biol. 1995 Oct 1;5(10):1191–1200. doi: 10.1016/s0960-9822(95)00235-1. [DOI] [PubMed] [Google Scholar]
  10. Gonzalez F. A., Raden D. L., Davis R. J. Identification of substrate recognition determinants for human ERK1 and ERK2 protein kinases. J Biol Chem. 1991 Nov 25;266(33):22159–22163. [PubMed] [Google Scholar]
  11. Gorman C. M., Moffat L. F., Howard B. H. Recombinant genomes which express chloramphenicol acetyltransferase in mammalian cells. Mol Cell Biol. 1982 Sep;2(9):1044–1051. doi: 10.1128/mcb.2.9.1044. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hibi M., Lin A., Smeal T., Minden A., Karin M. Identification of an oncoprotein- and UV-responsive protein kinase that binds and potentiates the c-Jun activation domain. Genes Dev. 1993 Nov;7(11):2135–2148. doi: 10.1101/gad.7.11.2135. [DOI] [PubMed] [Google Scholar]
  13. Hill C. S., Marais R., John S., Wynne J., Dalton S., Treisman R. Functional analysis of a growth factor-responsive transcription factor complex. Cell. 1993 Apr 23;73(2):395–406. doi: 10.1016/0092-8674(93)90238-l. [DOI] [PubMed] [Google Scholar]
  14. Jenuwein T., Müller R. Structure-function analysis of fos protein: a single amino acid change activates the immortalizing potential of v-fos. Cell. 1987 Feb 27;48(4):647–657. doi: 10.1016/0092-8674(87)90243-1. [DOI] [PubMed] [Google Scholar]
  15. Johnson R. S., van Lingen B., Papaioannou V. E., Spiegelman B. M. A null mutation at the c-jun locus causes embryonic lethality and retarded cell growth in culture. Genes Dev. 1993 Jul;7(7B):1309–1317. doi: 10.1101/gad.7.7b.1309. [DOI] [PubMed] [Google Scholar]
  16. Johnson R., Spiegelman B., Hanahan D., Wisdom R. Cellular transformation and malignancy induced by ras require c-jun. Mol Cell Biol. 1996 Aug;16(8):4504–4511. doi: 10.1128/mcb.16.8.4504. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Kakidani H., Ptashne M. GAL4 activates gene expression in mammalian cells. Cell. 1988 Jan 29;52(2):161–167. doi: 10.1016/0092-8674(88)90504-1. [DOI] [PubMed] [Google Scholar]
  18. Kovary K., Bravo R. The jun and fos protein families are both required for cell cycle progression in fibroblasts. Mol Cell Biol. 1991 Sep;11(9):4466–4472. doi: 10.1128/mcb.11.9.4466. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Kyriakis J. M., Banerjee P., Nikolakaki E., Dai T., Rubie E. A., Ahmad M. F., Avruch J., Woodgett J. R. The stress-activated protein kinase subfamily of c-Jun kinases. Nature. 1994 May 12;369(6476):156–160. doi: 10.1038/369156a0. [DOI] [PubMed] [Google Scholar]
  20. Lanker S., Valdivieso M. H., Wittenberg C. Rapid degradation of the G1 cyclin Cln2 induced by CDK-dependent phosphorylation. Science. 1996 Mar 15;271(5255):1597–1601. doi: 10.1126/science.271.5255.1597. [DOI] [PubMed] [Google Scholar]
  21. Lazo P. S., Dorfman K., Noguchi T., Mattéi M. G., Bravo R. Structure and mapping of the fosB gene. FosB downregulates the activity of the fosB promoter. Nucleic Acids Res. 1992 Jan 25;20(2):343–350. doi: 10.1093/nar/20.2.343. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Lloyd A., Yancheva N., Wasylyk B. Transformation suppressor activity of a Jun transcription factor lacking its activation domain. Nature. 1991 Aug 15;352(6336):635–638. doi: 10.1038/352635a0. [DOI] [PubMed] [Google Scholar]
  23. Marais R., Wynne J., Treisman R. The SRF accessory protein Elk-1 contains a growth factor-regulated transcriptional activation domain. Cell. 1993 Apr 23;73(2):381–393. doi: 10.1016/0092-8674(93)90237-k. [DOI] [PubMed] [Google Scholar]
  24. Metz R., Kouzarides T., Bravo R. A C-terminal domain in FosB, absent in FosB/SF and Fra-1, which is able to interact with the TATA binding protein, is required for altered cell growth. EMBO J. 1994 Aug 15;13(16):3832–3842. doi: 10.1002/j.1460-2075.1994.tb06694.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Mumberg D., Lucibello F. C., Schuermann M., Müller R. Alternative splicing of fosB transcripts results in differentially expressed mRNAs encoding functionally antagonistic proteins. Genes Dev. 1991 Jul;5(7):1212–1223. doi: 10.1101/gad.5.7.1212. [DOI] [PubMed] [Google Scholar]
  26. Nakabeppu Y., Nathans D. A naturally occurring truncated form of FosB that inhibits Fos/Jun transcriptional activity. Cell. 1991 Feb 22;64(4):751–759. doi: 10.1016/0092-8674(91)90504-r. [DOI] [PubMed] [Google Scholar]
  27. Pulverer B. J., Kyriakis J. M., Avruch J., Nikolakaki E., Woodgett J. R. Phosphorylation of c-jun mediated by MAP kinases. Nature. 1991 Oct 17;353(6345):670–674. doi: 10.1038/353670a0. [DOI] [PubMed] [Google Scholar]
  28. Sadowski I., Ptashne M. A vector for expressing GAL4(1-147) fusions in mammalian cells. Nucleic Acids Res. 1989 Sep 25;17(18):7539–7539. doi: 10.1093/nar/17.18.7539. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Scharfmann R., Axelrod J. H., Verma I. M. Long-term in vivo expression of retrovirus-mediated gene transfer in mouse fibroblast implants. Proc Natl Acad Sci U S A. 1991 Jun 1;88(11):4626–4630. doi: 10.1073/pnas.88.11.4626. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Smeal T., Binetruy B., Mercola D. A., Birrer M., Karin M. Oncogenic and transcriptional cooperation with Ha-Ras requires phosphorylation of c-Jun on serines 63 and 73. Nature. 1991 Dec 12;354(6353):494–496. doi: 10.1038/354494a0. [DOI] [PubMed] [Google Scholar]
  31. Smeal T., Binetruy B., Mercola D., Grover-Bardwick A., Heidecker G., Rapp U. R., Karin M. Oncoprotein-mediated signalling cascade stimulates c-Jun activity by phosphorylation of serines 63 and 73. Mol Cell Biol. 1992 Aug;12(8):3507–3513. doi: 10.1128/mcb.12.8.3507. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Smith D. B., Johnson K. S. Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferase. Gene. 1988 Jul 15;67(1):31–40. doi: 10.1016/0378-1119(88)90005-4. [DOI] [PubMed] [Google Scholar]
  33. Tracy S., van der Geer P., Hunter T. The receptor-like protein-tyrosine phosphatase, RPTP alpha, is phosphorylated by protein kinase C on two serines close to the inner face of the plasma membrane. J Biol Chem. 1995 May 5;270(18):10587–10594. doi: 10.1074/jbc.270.18.10587. [DOI] [PubMed] [Google Scholar]
  34. Whitmarsh A. J., Shore P., Sharrocks A. D., Davis R. J. Integration of MAP kinase signal transduction pathways at the serum response element. Science. 1995 Jul 21;269(5222):403–407. doi: 10.1126/science.7618106. [DOI] [PubMed] [Google Scholar]
  35. Wisdom R., Yen J., Rashid D., Verma I. M. Transformation by FosB requires a trans-activation domain missing in FosB2 that can be substituted by heterologous activation domains. Genes Dev. 1992 Apr;6(4):667–675. doi: 10.1101/gad.6.4.667. [DOI] [PubMed] [Google Scholar]
  36. Wisdon R., Verma I. M. Transformation by Fos proteins requires a C-terminal transactivation domain. Mol Cell Biol. 1993 Dec;13(12):7429–7438. doi: 10.1128/mcb.13.12.7429. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Yen J., Wisdom R. M., Tratner I., Verma I. M. An alternative spliced form of FosB is a negative regulator of transcriptional activation and transformation by Fos proteins. Proc Natl Acad Sci U S A. 1991 Jun 15;88(12):5077–5081. doi: 10.1073/pnas.88.12.5077. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Zerial M., Toschi L., Ryseck R. P., Schuermann M., Müller R., Bravo R. The product of a novel growth factor activated gene, fos B, interacts with JUN proteins enhancing their DNA binding activity. EMBO J. 1989 Mar;8(3):805–813. doi: 10.1002/j.1460-2075.1989.tb03441.x. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Molecular and Cellular Biology are provided here courtesy of Taylor & Francis

RESOURCES