LESLIE E SIEBURTH

LESLIE E SIEBURTH portrait
  • Professor, Biology

Research

Research Summary

My research is at the intersection between genetics, cell biology, signaling, gene expression, and developmental biology. One major project centers around the bypass1 (bps1) mutant, which causes over-production of a signaling molecule that moves from the root, and inhibits shoot growth. The other project focuses on how developmental signals affect mRNA stability.

Research Statement

We use Arabidopsis as our model system, and a decade ago we carried out screens to identify mutants with defects in patterning of the leaf vascular system.  This screen yielded a rich assortment of mutants, and resulted in two major funded projects in my lab.  One project centers around the bypass1 (bps1) mutant, whose characterization led us to identify a root-to-shoot signaling pathway that appears to involve a novel signaling molecule with properties resembling a plant hormone.  We are currently working to identify the signaling molecule, its role in shoot development, and to characterize the cell biology of BPS1 proteins.   The other project arose from characterization of varicose (vcs) and trident (tdt) mutants, which have defects in mRNA decapping components.  Decapping removes the protective 7-methyl guanine nucleotide attached by a 5’-5’ triphosphate linkage (the cap) from mRNAs, which initiates 5’-to-3’ decay.  Traditionally the major model for mRNA decay, and especially decapping, has been yeast (Saccharomyces cerevisiae).  However, the decapping complex of both plants and animals contain a large scaffold (VCS) that is missing from yeast, and this plant/animal complex also carries out additional miRNA-related functions.   Our contributions to this field include the first demonstration that general cytoplasmic mRNA decay pathways have substrate specificity, elucidating roles for the decapping complex in miRNA directed translational regulation,  and identification of a novel cytoplasmic mRNA decay pathway that is conserved in plants and animals (but again missing in yeast).
 

Research Keywords

  • metabolomics, Interest Level: 5
  • RNA biology, Interest Level: 5
  • Plant Biology, Interest Level: 5
  • Genetics, Interest Level: 5
  • Developmental Genetics, Interest Level: 5
  • Developmental Biology, Interest Level: 5
  • Biochemistry, Interest Level: 3
  • Gene Expression, Interest Level: 5