Regulation of mRNA Translation Initiation in Development
Human
development requires exquisite spatial and temporal control of the proteins
that are expressed in a cell. Translation initiation factors are key players in
protein synthesis, and although alterations to these factors are found in a
wide array of genetic diseases, including cardiac or craniofacial disorders,
cancer, autism, and diabetes, the molecular basis for the resulting disease is
poorly understood. The overarching goal of my research is to discover how mRNA
translation regulation drives the dynamic gene programs during organismal
development and why childhood diseases result when this is dysregulated.
We
recently discovered that certain initiation factors moonlight in roles outside
of general translation to control the translation of select transcripts, thus
presenting a potential mechanism by which these proteins could drive
tissue-specific development. In particular, the 13-subunit eukaryotic
initiation factor complex eIF3 plays a major role in balancing cell
proliferation and differentiation by mediating specialized translation of ~500
mRNAs, through translation activation of cell growth regulation mRNAs such as Jun and translation repression of
myogenic factors like BTG1.
These
surprising findings lead to a number of important questions: How is the
activity of eIF3 in specialized translation regulated? What are the mRNAs
controlled by eIF3 during development? What is the subsequent effect on
development when eIF3 activity is dysregulated? We will answer these questions
using an integrative approach combining sequencing and computation analysis,
RNA-protein biochemistry, and genetics. Our immediate goal is to provide a
molecular understanding of eIF3-specialized translation during development;
while our long-term objective is to address why incorrect expression of
translation initiation factors leads to congenital diseases. These studies will
illuminate the importance of translation regulation during development and
provide insight into why detrimental childhood diseases result when this
regulation fails.