Signaling of cell fate determination by the TPD1 small protein and EMS1 receptor kinase
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Edited by Mark Estelle, Indiana University, Bloomington, IN, and approved December 18, 2007 (received for review September 17, 2007)
Abstract
Sexual reproduction requires the specification of cells with distinct fates in plants and animals. The EMS1 (also known as EXS) leucine-rich repeat receptor-like kinase (LRR-RLK) and TPD1 small protein play key roles in regulating somatic and reproductive cell fate determination in Arabidopsis anthers. Here, we show that ectopic expression of TPD1 causes abnormal differentiation of somatic and reproductive cells in anthers. In addition, ectopic TPD1 activity requires functional EMS1. Yeast two-hybrid, pull-down, and coimmunoprecipitation analyses further demonstrate that TPD1 interacts with EMS1 in vitro and in vivo. Moreover, TPD1 induces EMS1 phosphorylation in planta. Thus, our results suggest that TPD1 serves as a ligand for the EMS1 receptor kinase to signal cell fate determination during plant sexual reproduction.
Footnotes
- *To whom correspondence should be addressed at: Department of Biological Sciences, University of Wisconsin, Lapham Hall, S181, 3209 North Maryland Avenue, Milwaukee, WI 53211. E-mail: dzhao{at}uwm.edu
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Author contributions: G.J. and D.Z. designed research; G.J., X.L., H.A.O., and D.Z. performed research; G.J. and D.Z. analyzed data; and D.Z. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0708795105/DC1.
- © 2008 by The National Academy of Sciences of the USA
