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  • The EMBO Journal (2004) 23, 2216 - 2225
  • doi:10.1038/sj.emboj.7600238

Published online: 13 May 2004

Talin B is required for force transmission in morphogenesis of Dictyostelium

Masatsune Tsujiokaa, Kunito Yoshidab and Kei Inouye

  1. Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, Japan

Correspondence to:

Kei Inouye, Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan. Tel.: +81 75 753 4130; Fax: +81 75 753 4137; E-mail: inoue@cosmos.bot.kyoto-u.ac.jp

aPresent address: Wellcome Trust Biocentre, School of Life Science, University of Dundee, Dow Street, Dundee DD1 5EH, UK

bPresent address: Department of Biological Sciences, Sir Alexander Fleming Building, Imperial College London, London SW7 2AZ, UK

Received 20 January 2003; Accepted 21 April 2004

Talin plays a key role in the assembly and stabilisation of focal adhesions, but whether it is directly involved in force transmission during morphogenesis remains to be elucidated. We show that the traction force of Dictyostelium cells mutant for one of its two talin genes talB is considerably smaller than that of wild-type cells, both in isolation and within tissues undergoing morphogenetic movement. The motility of mutant cells in tightly packed tissues in vivo or under strong resistance conditions in vitro was lower than that of wild-type cells, but their motility under low external force conditions was not impaired, indicating inefficient transmission of force in mutant cells. Antibody staining revealed that the talB gene product (talin B) exists as small units subjacent to the cell membrane at adhesion sites without forming large focal adhesion-like assemblies. The total amount of talin B on the cell membrane was larger in prestalk cells, which exert larger force than prespore cells during morphogenesis. We conclude that talin B is involved in force transmission between the cytoskeleton and cell exterior.

  • Keywords:

    • cytoskeleton,
    • Dictyostelium,
    • morphogenesis,
    • talin,
    • traction force