Cofilin phosphorylation by LIM-kinase 1 and its role in Rac-mediated actin reorganization

Abstract

Rac is a small GTPase of the Rho family that mediates stimulus-induced actin cytoskeletal reorganization to generate lamellipodia1,2,3,4,5. Little is known about the signalling pathways that link Rac activation to changes in actin filament dynamics. Cofilin is known to be a potent regulator of actin filament dynamics6,7,8,9,10, and its ability to bind and depolymerize actin is abolished by phosphorylation of serine residue at 3 (refs 11, 12); however, the kinases responsible for this phosphorylation have not been identified. Here we show that LIM-kinase 1 (LIMK-1), a serine/threonine kinase containing LIM and PDZ domains13,14,15,16, phosphorylates cofilin at Ser 3, both in vitro and in vivo. When expressed in cultured cells, LIMK-1 induces actin reorganization and reverses cofilin-induced actin depolymerization. Expression of an inactive form of LIMK-1 suppresses lamellipodium formation induced by Rac or insulin. Furthermore, insulin and an active form of Rac increase the activity of LIMK-1. Taken together, our results indicate that LIMK-1 participates in Rac-mediated actin cytoskeletal reorganization, probably by phosphorylating cofilin.

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Figure 1: LIMK-1 binds to F-actin and induces actin reorganization.
Figure 2: Phosphorylation of cofilin by LIMK-1.
Figure 3: Involvement of LIMK-1 in Rac signalling.
Figure 4: Involvement of LIMK-1 in insulin-induced formation of membrane ruffling.

References

  1. 1

    Hall, A. Rho GTPases and the actin cytoskeleton. Science 279, 509–514 (1998).

    ADS  CAS  Article  Google Scholar 

  2. 2

    Tapon, N. & Hall, A. Rho, Rac and Cdc42 GTPases regulate the organization of the actin cytoskeleton. Curr. Opin. Cell Biol. 9, 86–92 (1997).

    CAS  Article  Google Scholar 

  3. 3

    Ridley, A. J., Paterson, H. F., Johnston, C. L., Diekmann, D. & Hall, A. The small GTP-binding protein rac regulates growth factor-induced membrane ruffling. Cell 70, 401–410 (1992).

    CAS  Article  Google Scholar 

  4. 4

    Nobes, C. D. & Hall, A. Rho, Rac, and Cdc42 GTPases regulate the assembly of multimolecular focal complexes associated with actin stress fibers, lamellipodia, and filopodia. Cell 81, 53–62 (1995).

    CAS  Article  Google Scholar 

  5. 5

    Nishiyama, T. et al. rac p21 is involved in insulin-induced membrane ruffling and rho p21 is involved in hepatocyte growth factor- and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced membrane ruffling in KB cells. Mol. Cell. Biol. 14, 2447–2456 (1994).

    CAS  Article  Google Scholar 

  6. 6

    Nishida, E., Maekawa, S. & Sakai, H. Cofilin, a protein in porcine brain that binds to actin filaments and inhibits their interactions with myosin and tropomyosin. Biochemistry 23, 5307–5313 (1984).

    CAS  Article  Google Scholar 

  7. 7

    Moon, A. & Drubin, D. G. The ADF/cofilin proteins: stimulus-responsive modulators of actin dynamics. Mol. Biol. Cell 6, 1423–1431 (1995).

    CAS  Article  Google Scholar 

  8. 8

    Therriot, J. A. Accelerating on a treadmill: ADF/cofilin promotes rapid actin filament turnover in the dynamic cytoskeleton. J. Cell Biol. 136, 1165–1168 (1997).

    Article  Google Scholar 

  9. 9

    Welch, M. D., Mallavarapu, A., Rosenblatt, J. & Mitchison, T. J. Actin dynamics in vivo. Curr. Opin. Cell Biol. 9, 54–61 (1997).

    CAS  Article  Google Scholar 

  10. 10

    Carlier, M.-F. & Pantaloni, D. Control of actin dynamics in cell motility. J. Mol. Biol. 269, 459–467 (1997).

    CAS  Article  Google Scholar 

  11. 11

    Agnew, B. J., Minamide, L. S. & Bamburg, J. R. Reactivation of phosphorylated actin depolymerizing factor and identification of the regulatory site. J. Biol. Chem. 270, 17582–17587 (1995).

    CAS  Article  Google Scholar 

  12. 12

    Moriyama, K., Iida, K. & Yahara, I. Phosphorylation of Ser-3 of cofilin regulates its essential function on actin. Genes Cells 1, 73–86 (1996).

    CAS  Article  Google Scholar 

  13. 13

    Mizuno, K. et al. Identification of a human cDNA encoding a novel protein kinase with two repeats of the LIM/double zinc finger motif. Oncogene 9, 1605–1612 (1994).

    CAS  PubMed  Google Scholar 

  14. 14

    Bernard, O., Ganiatsas, S., Kannourakis, G. & Dringen, R. Kiz-1, a protein with LIM zinc finger and kinase domains, is expressed mainly in neurons. Cell Growth Differ. 5, 1159–1171 (1994).

    CAS  PubMed  Google Scholar 

  15. 15

    Okano, I. et al. Identification and characterization of a novel family of serine/threonine kinases containing N-terminal two LIM motifs. J. Biol. Chem. 270, 31321–31330 (1995).

    CAS  Article  Google Scholar 

  16. 16

    Nunoue, K., Ohashi, K., Okano, I. & Mizuno, K. LIMK-1 and LIMK-2, two members of a LIM motif-containing protein kinase family. Oncogene 11, 701–710 (1995).

    CAS  PubMed  Google Scholar 

  17. 17

    Ridley, A. J. & Hall, A. The small GTP-binding protein rho regulates the assembly of focal adhesions and actin stress fibers in response to growth factors. Cell 70, 389–399 (1992).

    CAS  Article  Google Scholar 

  18. 18

    Hiraoka, J., Okano, I., Higuchi, O., Yang, N. & Mizuno, K. Self-association of LIM-kinase 1 mediated by the interaction between an N-terminal LIM domain and a C-terminal kinase domain. FEBS Lett. 399, 117–121 (1996).

    CAS  Article  Google Scholar 

  19. 19

    Kuroda, S. et al. Identification of IQGAP as a putative target for the small GTPases, CDC42 and Rac1. J. Biol. Chem. 271, 23363–23367 (1996).

    CAS  Article  Google Scholar 

  20. 20

    Roof, D. J., Hayes, A., Adamian, M., Chishti, A. H. & Li, T. Molecular characterization of abLIM, a novel actin-binding and double zinc finger protein. J. Cell Biol. 138, 575–588 (1997).

    CAS  Article  Google Scholar 

  21. 21

    Ohashi, K. et al. Stimulation of Sky receptor tyrosine kinase by the product of growth arrest-specific gene 6. J. Biol. Chem. 270, 22681–22684 (1995).

    CAS  Article  Google Scholar 

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Acknowledgements

We thank S. Kuroda, K. Kaibuchi and K. Ito for plasmids of Rho, Rac and Cdc42; T.Amano and A. Miyata for technical assistance; and Y. Fujiki, H. Matsuo, C. Ikebe, M. Ohara and K.Toyoshima for comments. This work was supported by grants from the Ministry of Education, Science, Sports and Culture of Japan and the Japan Science and Technology Corporation (to K.M.).

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Correspondence to Kensaku Mizuno.

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Yang, N., Higuchi, O., Ohashi, K. et al. Cofilin phosphorylation by LIM-kinase 1 and its role in Rac-mediated actin reorganization. Nature 393, 809–812 (1998). https://doi.org/10.1038/31735

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