Abstract
The cactus and dorsal proteins are Drosophila homologues of mammalian I kappa B cytoplasmic anchor proteins and rel/NF kappa B transcription factors respectively. They are required for the generation of embryonic dorsoventral polarity and probably at later developmental stages for an innate immune response. In this paper we report on the properties of SLDL, a derivative of the SL2 cell line in which dorsal is expressed constitutively. In SLDL cells biosynthesis of cactus protein is stimulated by approximately 4-fold when compared with SL2 cells. Enhanced biosynthesis of cactus protein cannot be explained solely on the basis of increased expression of the cactus gene as the level of the corresponding mRNA is only 2-fold higher than in SL2 cells. On the basis of these findings we propose that free cytoplasmic dorsal protein is able, directly or indirectly to stimulate translation of the cactus mRNA. Such an arrangement would enable the dorsal protein to be buffered in the cytoplasm of the resting cell over a wide range of concentrations. We also show here that subsequent to biosynthesis the cactus protein is either rapidly degraded or incorporated into complexes with dorsal. Protein that does not associate with dorsal has a half-life of approximately 40 min whereas that which is incorporated into complexes is very stable, having a half life in excess of 24 h. The complexed cactus protein is acted on by protein kinases which generate distinct phophorylated isoforms.
Full text
PDF







Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Beg A. A., Finco T. S., Nantermet P. V., Baldwin A. S., Jr Tumor necrosis factor and interleukin-1 lead to phosphorylation and loss of I kappa B alpha: a mechanism for NF-kappa B activation. Mol Cell Biol. 1993 Jun;13(6):3301–3310. doi: 10.1128/mcb.13.6.3301. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown K., Park S., Kanno T., Franzoso G., Siebenlist U. Mutual regulation of the transcriptional activator NF-kappa B and its inhibitor, I kappa B-alpha. Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2532–2536. doi: 10.1073/pnas.90.6.2532. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Frantz B., Nordby E. C., Bren G., Steffan N., Paya C. V., Kincaid R. L., Tocci M. J., O'Keefe S. J., O'Neill E. A. Calcineurin acts in synergy with PMA to inactivate I kappa B/MAD3, an inhibitor of NF-kappa B. EMBO J. 1994 Feb 15;13(4):861–870. doi: 10.1002/j.1460-2075.1994.tb06329.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gay N. J., Keith F. J. Drosophila Toll and IL-1 receptor. Nature. 1991 May 30;351(6325):355–356. doi: 10.1038/351355b0. [DOI] [PubMed] [Google Scholar]
- Gay N. J., Ntwasa M. The Drosophila ankyrin repeat protein cactus has a predominantly alpha-helical secondary structure. FEBS Lett. 1993 Dec 6;335(2):155–160. doi: 10.1016/0014-5793(93)80720-f. [DOI] [PubMed] [Google Scholar]
- Gay N. J., Poole S. J., Kornberg T. B. The Drosophila engrailed protein is phosphorylated by a serine-specific protein kinase. Nucleic Acids Res. 1988 Jul 25;16(14A):6637–6647. doi: 10.1093/nar/16.14.6637. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Geiduschek E. P., Tocchini-Valentini G. P. Transcription by RNA polymerase III. Annu Rev Biochem. 1988;57:873–914. doi: 10.1146/annurev.bi.57.070188.004301. [DOI] [PubMed] [Google Scholar]
- Geisler R., Bergmann A., Hiromi Y., Nüsslein-Volhard C. cactus, a gene involved in dorsoventral pattern formation of Drosophila, is related to the I kappa B gene family of vertebrates. Cell. 1992 Nov 13;71(4):613–621. doi: 10.1016/0092-8674(92)90595-4. [DOI] [PubMed] [Google Scholar]
- Henkel T., Zabel U., van Zee K., Müller J. M., Fanning E., Baeuerle P. A. Intramolecular masking of the nuclear location signal and dimerization domain in the precursor for the p50 NF-kappa B subunit. Cell. 1992 Mar 20;68(6):1121–1133. doi: 10.1016/0092-8674(92)90083-o. [DOI] [PubMed] [Google Scholar]
- Ip Y. T., Reach M., Engstrom Y., Kadalayil L., Cai H., González-Crespo S., Tatei K., Levine M. Dif, a dorsal-related gene that mediates an immune response in Drosophila. Cell. 1993 Nov 19;75(4):753–763. doi: 10.1016/0092-8674(93)90495-c. [DOI] [PubMed] [Google Scholar]
- Isoda K., Nüsslein-Volhard C. Disulfide cross-linking in crude embryonic lysates reveals three complexes of the Drosophila morphogen dorsal and its inhibitor cactus. Proc Natl Acad Sci U S A. 1994 Jun 7;91(12):5350–5354. doi: 10.1073/pnas.91.12.5350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Isoda K., Roth S., Nüsslein-Volhard C. The functional domains of the Drosophila morphogen dorsal: evidence from the analysis of mutants. Genes Dev. 1992 Apr;6(4):619–630. doi: 10.1101/gad.6.4.619. [DOI] [PubMed] [Google Scholar]
- Jiang J., Levine M. Binding affinities and cooperative interactions with bHLH activators delimit threshold responses to the dorsal gradient morphogen. Cell. 1993 Mar 12;72(5):741–752. doi: 10.1016/0092-8674(93)90402-c. [DOI] [PubMed] [Google Scholar]
- Keith F. J., Gay N. J. The Drosophila membrane receptor Toll can function to promote cellular adhesion. EMBO J. 1990 Dec;9(13):4299–4306. doi: 10.1002/j.1460-2075.1990.tb07878.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kidd S. Characterization of the Drosophila cactus locus and analysis of interactions between cactus and dorsal proteins. Cell. 1992 Nov 13;71(4):623–635. doi: 10.1016/0092-8674(92)90596-5. [DOI] [PubMed] [Google Scholar]
- Kubota K., Keith F. J., Gay N. J. Relocalization of Drosophila dorsal protein can be induced by a rise in cytoplasmic calcium concentration and the expression of constitutively active but not wild-type Toll receptors. Biochem J. 1993 Dec 1;296(Pt 2):497–503. doi: 10.1042/bj2960497. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Le Bail O., Schmidt-Ullrich R., Israël A. Promoter analysis of the gene encoding the I kappa B-alpha/MAD3 inhibitor of NF-kappa B: positive regulation by members of the rel/NF-kappa B family. EMBO J. 1993 Dec 15;12(13):5043–5049. doi: 10.1002/j.1460-2075.1993.tb06197.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mellits K. H., Hay R. T., Goodbourn S. Proteolytic degradation of MAD3 (I kappa B alpha) and enhanced processing of the NF-kappa B precursor p105 are obligatory steps in the activation of NF-kappa B. Nucleic Acids Res. 1993 Nov 11;21(22):5059–5066. doi: 10.1093/nar/21.22.5059. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ntwasa M., Buchanan S. G., Gay N. J. Drosophila ribosomal protein L18a: cDNA sequence, expression and chromosomal localization of the gene. Biochim Biophys Acta. 1994 Jun 21;1218(2):210–212. doi: 10.1016/0167-4781(94)90014-0. [DOI] [PubMed] [Google Scholar]
- Rogers S., Wells R., Rechsteiner M. Amino acid sequences common to rapidly degraded proteins: the PEST hypothesis. Science. 1986 Oct 17;234(4774):364–368. doi: 10.1126/science.2876518. [DOI] [PubMed] [Google Scholar]
- Roth S. Axis determination. Proteolytic generation of a morphogen. Curr Biol. 1994 Aug 1;4(8):755–757. doi: 10.1016/s0960-9822(00)00170-6. [DOI] [PubMed] [Google Scholar]
- Rushlow C. A., Han K., Manley J. L., Levine M. The graded distribution of the dorsal morphogen is initiated by selective nuclear transport in Drosophila. Cell. 1989 Dec 22;59(6):1165–1177. doi: 10.1016/0092-8674(89)90772-1. [DOI] [PubMed] [Google Scholar]
- Schneider D. S., Hudson K. L., Lin T. Y., Anderson K. V. Dominant and recessive mutations define functional domains of Toll, a transmembrane protein required for dorsal-ventral polarity in the Drosophila embryo. Genes Dev. 1991 May;5(5):797–807. doi: 10.1101/gad.5.5.797. [DOI] [PubMed] [Google Scholar]
- Scott M. L., Fujita T., Liou H. C., Nolan G. P., Baltimore D. The p65 subunit of NF-kappa B regulates I kappa B by two distinct mechanisms. Genes Dev. 1993 Jul;7(7A):1266–1276. doi: 10.1101/gad.7.7a.1266. [DOI] [PubMed] [Google Scholar]
- Steward R., Govind S. Dorsal-ventral polarity in the Drosophila embryo. Curr Opin Genet Dev. 1993 Aug;3(4):556–561. doi: 10.1016/0959-437x(93)90090-c. [DOI] [PubMed] [Google Scholar]
- Sun S. C., Ganchi P. A., Ballard D. W., Greene W. C. NF-kappa B controls expression of inhibitor I kappa B alpha: evidence for an inducible autoregulatory pathway. Science. 1993 Mar 26;259(5103):1912–1915. doi: 10.1126/science.8096091. [DOI] [PubMed] [Google Scholar]
- Tanaka M., Herr W. Differential transcriptional activation by Oct-1 and Oct-2: interdependent activation domains induce Oct-2 phosphorylation. Cell. 1990 Feb 9;60(3):375–386. doi: 10.1016/0092-8674(90)90589-7. [DOI] [PubMed] [Google Scholar]
- Whalen A. M., Steward R. Dissociation of the dorsal-cactus complex and phosphorylation of the dorsal protein correlate with the nuclear localization of dorsal. J Cell Biol. 1993 Nov;123(3):523–534. doi: 10.1083/jcb.123.3.523. [DOI] [PMC free article] [PubMed] [Google Scholar]