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  • The EMBO Journal (2002) 21, 898 - 908
  • doi:10.1093/emboj/21.5.898

SHEPHERD is the Arabidopsis GRP94 responsible for the formation of functional CLAVATA proteins

Sumie Ishiguro1, Yuhko Watanabe1, Natsuko Ito1, Hideko Nonaka2, Norimasa Takeda1, Tomoko Sakai1, Hiroshi Kanaya1 and Kiyotaka Okada1

  1. Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
  2. National Institute for Basic Biology, Okazaki 444-8585, Japan

Correspondence to:

Kiyotaka Okada, E-mail: kiyo@ok-lab.bot.kyoto-u.ac.jp

Received 17 September 2001; Accepted 11 January 2002; Revised 10 December 2001

The Arabidopsis shepherd (shd) mutant shows expanded shoot apical meristems (SAM) and floral meristems (FM), disorganized root apical meristems, and defects in pollen tube elongation. We have discovered that SHD encodes an ortholog of GRP94, an ER-resident HSP90-like protein. Since the shd phenotypes in SAM and FM are similar to those of the clavata (clv) mutants, we have explored the possibility that CLV complex members could be SHD targets. The SAM and FM morphology of shd clv double mutants are indistinguishable from those of clv single mutants, and the wuschel (wus) mutation is completely epistatic to the shd mutation, indicating that SHD and CLV act in the same genetic pathway to suppress WUS function. Moreover, the effects of CLV3 overexpression that result in the elimination of SAM activity were abolished in the shd mutant, indicating that CLV function is dependent on SHD function. Therefore, we conclude that the SHD protein is required for the correct folding and/or complex formation of CLV proteins.

  • Keywords:

    • CLAVATA,
    • GRP94,
    • meristem,
    • molecular chaperon,
    • SHEPHERD