My research has been focused on an
important, yet sometimes overlooked aspect of gene expression, the
regulation of mRNA translation. More specifically, I have concentrated my
studies on a set of 12 kDa acidic ribosomal phosphoproteins known as the
P-proteins. The P-proteins form a universally conserved lateral stalk
structure in the active site of the large ribosomal subunit (60S) and are
thought to assist in the late initiation and elongation phases of
translation via interactions with tRNA, mRNA and translation factors.
My research has shown that (1) maize ribosomes possess a distinct acidic
P-protein (published in Plant Physiology), (2) this P-protein is
evolutionarily distinct and is unique to plants (published in The
Proceedings of the National Academy of Sciences) and (3) the presence,
abundance and phosphorylation of the P-proteins of maize ribosomes varies
during development and in response to environmental cues (published in
The Journal of Biological Chemistry). Currently, I have incorporated
the use of model plant Arabidopsis thaliana to investigate the role
of the P-proteins, as transformation experiments to examine both
overexpression and antisense suppression of target genes have been well
established. In addition, my interests include plant ribosomes as a whole
and ribosomal proteins. A database mining project has resulted in the
identification of 249 Arabidopsis ribosomal protein genes (published
in Plant Physiology), and I have been involved in a proteomics based
approach to identify all of the Arabidopsis ribosomal proteins
utilizing two-dimensional gel electrophoresis and MALDI-TOF mass
spectrometry. Finally, mutations in ribosomal protein genes in
Drosophila lead to strong developmental phenotypes collectively
referred to as the “Minute” phenotype. To date, only a few mutations into
Arabidopsis ribosomal protein genes have been described. Currently I
am involved in a large scale project in which we are analyzing insertional
mutations into ribosomal protein genes. The Arabidopsis mutants,
generated via insertion of Agrobacterium T-DNA, are readily
available through the Salk Institute Genome Analysis Laboratory.
