SHEPHERD is the Arabidopsis GRP94 responsible for the formation of functional CLAVATA proteins.
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.
Ishiguro
Sumie
S
Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Watanabe
Yuhko
Y
Ito
Natsuko
N
Nonaka
Hideko
H
Takeda
Norimasa
N
Sakai
Tomoko
T
Kanaya
Hiroshi
H
Okada
Kiyotaka
K
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D004843:Epistasis, Genetic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018840:HSP70 Heat-Shock Proteins / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology; D008565:Membrane Proteins / Q000378:metabolism* / Q000502:physiology; D018519:Meristem / Q000502:physiology*; D018832:Molecular Chaperones / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000378:metabolism*; D018514:Plant Structures / Q000648:ultrastructure; D017510:Protein Folding; D017346:Protein Serine-Threonine Kinases; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000502:physiology; D013329:Structure-Activity Relationship; D013696:Temperature
C118167:AT2G27250 protein, Arabidopsis; D029681:Arabidopsis Proteins; C401621:CLV2 protein, Arabidopsis; D018840:HSP70 Heat-Shock Proteins; D018398:Homeodomain Proteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C116421:WUSCHEL protein, Arabidopsis; C018551:glucose-regulated proteins; D020794:Receptor Protein-Tyrosine Kinases; C118166:CLV1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases