Abstract
We have identified a basic sequence in the N-terminal region of the 67-kDa serum response factor (p67SRF or SRF) responsible for its nuclear localization. A peptide containing this nuclear localization signal (NLS) translocates rabbit immunoglobulin G (IgG) into the nucleus as efficiently as a peptide encoding the simian virus 40 NLS. This effect is abolished by substituting any two of the four basic residues in this NLS. Overexpression of a modified form of SRF in which these basic residues have been mutated confirms the absolute requirement for this sequence, and not the other basic amino acid sequences adjacent to it, in the nuclear localization of SRF. Since this NLS is in close proximity to potential phosphorylation sites for the cAMP-dependent protein kinase (A-kinase), we further investigated if A-kinase plays a role in the nuclear location of SRF. The nuclear transport of SRF proteins requires basal A-kinase activity, since inhibition of A-kinase by using either the specific inhibitory peptide PKIm or type II regulatory subunits (RII) completely prevents the nuclear localization of plasmid-expressed tagged SRF or an SRF-NLS-IgG conjugate. Direct phosphorylation of SRF by A-kinase can be discounted in this effect, since mutation of the putative phosphorylation sites in either the NLS peptide or the encoded full-length SRF protein had no effect on nuclear transport of the mutants. Finally, in support of an implication of A-kinase-dependent phosphorylation in a more general mechanism affecting nuclear import, we show that the nuclear transport of a simian virus 40-NLS-conjugated IgG or purified cyclin A protein is also blocked by inhibition of A-kinase, even though neither contains any potential sites for phosphorylation by A-kinase or can be phosphorylated by A-kinase in vitro.
Full Text
The Full Text of this article is available as a PDF (980.4 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Adam S. A., Lobl T. J., Mitchell M. A., Gerace L. Identification of specific binding proteins for a nuclear location sequence. Nature. 1989 Jan 19;337(6204):276–279. doi: 10.1038/337276a0. [DOI] [PubMed] [Google Scholar]
- Bornslaeger E. A., Mattei P., Schultz R. M. Involvement of cAMP-dependent protein kinase and protein phosphorylation in regulation of mouse oocyte maturation. Dev Biol. 1986 Apr;114(2):453–462. doi: 10.1016/0012-1606(86)90209-5. [DOI] [PubMed] [Google Scholar]
- Chambers A. E., Kotecha S., Towers N., Mohun T. J. Muscle-specific expression of SRF-related genes in the early embryo of Xenopus laevis. EMBO J. 1992 Dec;11(13):4981–4991. doi: 10.1002/j.1460-2075.1992.tb05605.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davis L. I., Fink G. R. The NUP1 gene encodes an essential component of the yeast nuclear pore complex. Cell. 1990 Jun 15;61(6):965–978. doi: 10.1016/0092-8674(90)90062-j. [DOI] [PubMed] [Google Scholar]
- Dingwall C., Laskey R. A. Nuclear targeting sequences--a consensus? Trends Biochem Sci. 1991 Dec;16(12):478–481. doi: 10.1016/0968-0004(91)90184-w. [DOI] [PubMed] [Google Scholar]
- Dingwall C., Laskey R. A. Protein import into the cell nucleus. Annu Rev Cell Biol. 1986;2:367–390. doi: 10.1146/annurev.cb.02.110186.002055. [DOI] [PubMed] [Google Scholar]
- Dingwall C., Robbins J., Dilworth S. M., Roberts B., Richardson W. D. The nucleoplasmin nuclear location sequence is larger and more complex than that of SV-40 large T antigen. J Cell Biol. 1988 Sep;107(3):841–849. doi: 10.1083/jcb.107.3.841. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fernandez A., Mery J., Vandromme M., Basset M., Cavadore J. C., Lamb N. J. Effective intracellular inhibition of the cAMP-dependent protein kinase by microinjection of a modified form of the specific inhibitor peptide PKi in living fibroblasts. Exp Cell Res. 1991 Aug;195(2):468–477. doi: 10.1016/0014-4827(91)90398-e. [DOI] [PubMed] [Google Scholar]
- Garcia-Bustos J., Heitman J., Hall M. N. Nuclear protein localization. Biochim Biophys Acta. 1991 Mar 7;1071(1):83–101. doi: 10.1016/0304-4157(91)90013-m. [DOI] [PubMed] [Google Scholar]
- Gashler A. L., Swaminathan S., Sukhatme V. P. A novel repression module, an extensive activation domain, and a bipartite nuclear localization signal defined in the immediate-early transcription factor Egr-1. Mol Cell Biol. 1993 Aug;13(8):4556–4571. doi: 10.1128/mcb.13.8.4556. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gauthier-Rouvière C., Basset M., Blanchard J. M., Cavadore J. C., Fernandez A., Lamb N. J. Casein kinase II induces c-fos expression via the serum response element pathway and p67SRF phosphorylation in living fibroblasts. EMBO J. 1991 Oct;10(10):2921–2930. doi: 10.1002/j.1460-2075.1991.tb07842.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gauthier-Rouvière C., Cavadore J. C., Blanchard J. M., Lamb N. J., Fernandez A. p67SRF is a constitutive nuclear protein implicated in the modulation of genes required throughout the G1 period. Cell Regul. 1991 Jul;2(7):575–588. doi: 10.1091/mbc.2.7.575. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gauthier-Rouvière C., Caï Q. Q., Lautredou N., Fernandez A., Blanchard J. M., Lamb N. J. Expression and purification of the DNA-binding domain of SRF: SRF-DB, a part of a DNA-binding protein which can act as a dominant negative mutant in vivo. Exp Cell Res. 1993 Dec;209(2):208–215. doi: 10.1006/excr.1993.1303. [DOI] [PubMed] [Google Scholar]
- Gilman M. Z., Wilson R. N., Weinberg R. A. Multiple protein-binding sites in the 5'-flanking region regulate c-fos expression. Mol Cell Biol. 1986 Dec;6(12):4305–4316. doi: 10.1128/mcb.6.12.4305. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Girard F., Strausfeld U., Fernandez A., Lamb N. J. Cyclin A is required for the onset of DNA replication in mammalian fibroblasts. Cell. 1991 Dec 20;67(6):1169–1179. doi: 10.1016/0092-8674(91)90293-8. [DOI] [PubMed] [Google Scholar]
- Gómez-Márquez J., Segade F. Prothymosin alpha is a nuclear protein. FEBS Lett. 1988 Jan 4;226(2):217–219. doi: 10.1016/0014-5793(88)81425-x. [DOI] [PubMed] [Google Scholar]
- House C., Kemp B. E. Protein kinase C contains a pseudosubstrate prototope in its regulatory domain. Science. 1987 Dec 18;238(4834):1726–1728. doi: 10.1126/science.3686012. [DOI] [PubMed] [Google Scholar]
- Janknecht R., Hipskind R. A., Houthaeve T., Nordheim A., Stunnenberg H. G. Identification of multiple SRF N-terminal phosphorylation sites affecting DNA binding properties. EMBO J. 1992 Mar;11(3):1045–1054. doi: 10.1002/j.1460-2075.1992.tb05143.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kalderon D., Richardson W. D., Markham A. F., Smith A. E. Sequence requirements for nuclear location of simian virus 40 large-T antigen. Nature. 1984 Sep 6;311(5981):33–38. doi: 10.1038/311033a0. [DOI] [PubMed] [Google Scholar]
- Klamut H. J., Gangopadhyay S. B., Worton R. G., Ray P. N. Molecular and functional analysis of the muscle-specific promoter region of the Duchenne muscular dystrophy gene. Mol Cell Biol. 1990 Jan;10(1):193–205. doi: 10.1128/mcb.10.1.193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lamb N. J., Cavadore J. C., Labbe J. C., Maurer R. A., Fernandez A. Inhibition of cAMP-dependent protein kinase plays a key role in the induction of mitosis and nuclear envelope breakdown in mammalian cells. EMBO J. 1991 Jun;10(6):1523–1533. doi: 10.1002/j.1460-2075.1991.tb07672.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lamb N. J., Fernandez A., Conti M. A., Adelstein R., Glass D. B., Welch W. J., Feramisco J. R. Regulation of actin microfilament integrity in living nonmuscle cells by the cAMP-dependent protein kinase and the myosin light chain kinase. J Cell Biol. 1988 Jun;106(6):1955–1971. doi: 10.1083/jcb.106.6.1955. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lanford R. E., Kanda P., Kennedy R. C. Induction of nuclear transport with a synthetic peptide homologous to the SV40 T antigen transport signal. Cell. 1986 Aug 15;46(4):575–582. doi: 10.1016/0092-8674(86)90883-4. [DOI] [PubMed] [Google Scholar]
- Li R., Shi Y., Thomas J. O. Intracellular distribution of a nuclear localization signal binding protein. Exp Cell Res. 1992 Oct;202(2):355–365. doi: 10.1016/0014-4827(92)90085-m. [DOI] [PubMed] [Google Scholar]
- Maller J. L., Krebs E. G. Progesterone-stimulated meiotic cell division in Xenopus oocytes. Induction by regulatory subunit and inhibition by catalytic subunit of adenosine 3':5'-monophosphate-dependent protein kinase. J Biol Chem. 1977 Mar 10;252(5):1712–1718. [PubMed] [Google Scholar]
- McVey D., Brizuela L., Mohr I., Marshak D. R., Gluzman Y., Beach D. Phosphorylation of large tumour antigen by cdc2 stimulates SV40 DNA replication. Nature. 1989 Oct 12;341(6242):503–507. doi: 10.1038/341503a0. [DOI] [PubMed] [Google Scholar]
- Meier U. T., Blobel G. A nuclear localization signal binding protein in the nucleolus. J Cell Biol. 1990 Dec;111(6 Pt 1):2235–2245. doi: 10.1083/jcb.111.6.2235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meier U. T., Blobel G. Nopp140 shuttles on tracks between nucleolus and cytoplasm. Cell. 1992 Jul 10;70(1):127–138. doi: 10.1016/0092-8674(92)90539-o. [DOI] [PubMed] [Google Scholar]
- Meijer L., Dostmann W., Genieser H. G., Butt E., Jastorff B. Starfish oocyte maturation: evidence for a cyclic AMP-dependent inhibitory pathway. Dev Biol. 1989 May;133(1):58–66. doi: 10.1016/0012-1606(89)90296-0. [DOI] [PubMed] [Google Scholar]
- Minty A., Kedes L. Upstream regions of the human cardiac actin gene that modulate its transcription in muscle cells: presence of an evolutionarily conserved repeated motif. Mol Cell Biol. 1986 Jun;6(6):2125–2136. doi: 10.1128/mcb.6.6.2125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mosialos G., Hamer P., Capobianco A. J., Laursen R. A., Gilmore T. D. A protein kinase-A recognition sequence is structurally linked to transformation by p59v-rel and cytoplasmic retention of p68c-rel. Mol Cell Biol. 1991 Dec;11(12):5867–5877. doi: 10.1128/mcb.11.12.5867. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nakabeppu Y., Nathans D. The basic region of Fos mediates specific DNA binding. EMBO J. 1989 Dec 1;8(12):3833–3841. doi: 10.1002/j.1460-2075.1989.tb08561.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nasmyth K., Adolf G., Lydall D., Seddon A. The identification of a second cell cycle control on the HO promoter in yeast: cell cycle regulation of SW15 nuclear entry. Cell. 1990 Aug 24;62(4):631–647. doi: 10.1016/0092-8674(90)90110-z. [DOI] [PubMed] [Google Scholar]
- Norman C., Runswick M., Pollock R., Treisman R. Isolation and properties of cDNA clones encoding SRF, a transcription factor that binds to the c-fos serum response element. Cell. 1988 Dec 23;55(6):989–1003. doi: 10.1016/0092-8674(88)90244-9. [DOI] [PubMed] [Google Scholar]
- Norris J. L., Manley J. L. Selective nuclear transport of the Drosophila morphogen dorsal can be established by a signaling pathway involving the transmembrane protein Toll and protein kinase A. Genes Dev. 1992 Sep;6(9):1654–1667. doi: 10.1101/gad.6.9.1654. [DOI] [PubMed] [Google Scholar]
- Pollock R., Treisman R. Human SRF-related proteins: DNA-binding properties and potential regulatory targets. Genes Dev. 1991 Dec;5(12A):2327–2341. doi: 10.1101/gad.5.12a.2327. [DOI] [PubMed] [Google Scholar]
- Prywes R., Roeder R. G. Purification of the c-fos enhancer-binding protein. Mol Cell Biol. 1987 Oct;7(10):3482–3489. doi: 10.1128/mcb.7.10.3482. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rihs H. P., Jans D. A., Fan H., Peters R. The rate of nuclear cytoplasmic protein transport is determined by the casein kinase II site flanking the nuclear localization sequence of the SV40 T-antigen. EMBO J. 1991 Mar;10(3):633–639. doi: 10.1002/j.1460-2075.1991.tb07991.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Roberts B. L., Richardson W. D., Smith A. E. The effect of protein context on nuclear location signal function. Cell. 1987 Jul 31;50(3):465–475. doi: 10.1016/0092-8674(87)90500-9. [DOI] [PubMed] [Google Scholar]
- Roux P., Blanchard J. M., Fernandez A., Lamb N., Jeanteur P., Piechaczyk M. Nuclear localization of c-Fos, but not v-Fos proteins, is controlled by extracellular signals. Cell. 1990 Oct 19;63(2):341–351. doi: 10.1016/0092-8674(90)90167-d. [DOI] [PubMed] [Google Scholar]
- Shi Y., Thomas J. O. The transport of proteins into the nucleus requires the 70-kilodalton heat shock protein or its cytosolic cognate. Mol Cell Biol. 1992 May;12(5):2186–2192. doi: 10.1128/mcb.12.5.2186. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silver P. A. How proteins enter the nucleus. Cell. 1991 Feb 8;64(3):489–497. doi: 10.1016/0092-8674(91)90233-o. [DOI] [PubMed] [Google Scholar]
- Silver P., Sadler I., Osborne M. A. Yeast proteins that recognize nuclear localization sequences. J Cell Biol. 1989 Sep;109(3):983–989. doi: 10.1083/jcb.109.3.983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stochaj U., Bossie M. A., van Zee K., Whalen A. M., Silver P. A. Analysis of conserved binding proteins for nuclear localization sequences. J Cell Sci. 1993 Jan;104(Pt 1):89–95. doi: 10.1242/jcs.104.1.89. [DOI] [PubMed] [Google Scholar]
- Stochaj U., Osborne M., Kurihara T., Silver P. A yeast protein that binds nuclear localization signals: purification localization, and antibody inhibition of binding activity. J Cell Biol. 1991 Jun;113(6):1243–1254. doi: 10.1083/jcb.113.6.1243. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stochaj U., Silver P. A. A conserved phosphoprotein that specifically binds nuclear localization sequences is involved in nuclear import. J Cell Biol. 1992 May;117(3):473–482. doi: 10.1083/jcb.117.3.473. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Treisman R., Ammerer G. The SRF and MCM1 transcription factors. Curr Opin Genet Dev. 1992 Apr;2(2):221–226. doi: 10.1016/s0959-437x(05)80277-1. [DOI] [PubMed] [Google Scholar]
- Treisman R. Identification and purification of a polypeptide that binds to the c-fos serum response element. EMBO J. 1987 Sep;6(9):2711–2717. doi: 10.1002/j.1460-2075.1987.tb02564.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Treisman R. Transient accumulation of c-fos RNA following serum stimulation requires a conserved 5' element and c-fos 3' sequences. Cell. 1985 Oct;42(3):889–902. doi: 10.1016/0092-8674(85)90285-5. [DOI] [PubMed] [Google Scholar]
- Vandromme M., Carnac G., Gauthier-Rouvière C., Fesquet D., Lamb N., Fernandez A. Nuclear import of the myogenic factor MyoD requires cAMP-dependent protein kinase activity but not the direct phosphorylation of MyoD. J Cell Sci. 1994 Feb;107(Pt 2):613–620. doi: 10.1242/jcs.107.2.613. [DOI] [PubMed] [Google Scholar]
- Vandromme M., Gauthier-Rouvière C., Carnac G., Lamb N., Fernandez A. Serum response factor p67SRF is expressed and required during myogenic differentiation of both mouse C2 and rat L6 muscle cell lines. J Cell Biol. 1992 Sep;118(6):1489–1500. doi: 10.1083/jcb.118.6.1489. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vriz S., Lemaitre J. M., Leibovici M., Thierry N., Méchali M. Comparative analysis of the intracellular localization of c-Myc, c-Fos, and replicative proteins during cell cycle progression. Mol Cell Biol. 1992 Aug;12(8):3548–3555. doi: 10.1128/mcb.12.8.3548. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wilson I. A., Niman H. L., Houghten R. A., Cherenson A. R., Connolly M. L., Lerner R. A. The structure of an antigenic determinant in a protein. Cell. 1984 Jul;37(3):767–778. doi: 10.1016/0092-8674(84)90412-4. [DOI] [PubMed] [Google Scholar]
- Yamasaki L., Kanda P., Lanford R. E. Identification of four nuclear transport signal-binding proteins that interact with diverse transport signals. Mol Cell Biol. 1989 Jul;9(7):3028–3036. doi: 10.1128/mcb.9.7.3028. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zeilig C. E., Goldberg N. D. Cell-cycle-related changes of 3':5'-cyclic GMP levels in Novikoff hepatoma cells. Proc Natl Acad Sci U S A. 1977 Mar;74(3):1052–1056. doi: 10.1073/pnas.74.3.1052. [DOI] [PMC free article] [PubMed] [Google Scholar]