3-dimensional Organization and Functions of Translation in Organelle Proximity

Introduction

In eukaryotic cells, many proteins are produced next to the organelles where they function, demonstrating a link between translation and protein targeting. The mechanisms of this connection are mostly unknown. In this proposal, I bring together the fields of translation regulation and organelle biogenesis to find this out.

Research Approach

I approach the problem with a powerful combination of functional genomics and cryogenic electron tomography (cryo-ET).

Mapping Proximal Translation

1. First, I want to create a quantitative map of proximal translation next to all the organelles and their sub-domains.
2. Using high-throughput imaging, I will determine localizations of all the mRNAs and their dependence on translation.
3. I will also map the positions and orientations of ribosomes next to all the membranes using proximity labeling and direct quantification of native ribosomes with cryo-ET.

Understanding Local Translation

Beyond mapping, I want to understand how this local translation map is adapted to different conditions.

1. Using high-throughput screening, I will determine what global and local factors establish and regulate proximal translation at each organelle.
2. Finally, I will investigate the role proximal translation plays in essential organelle functions and get mechanistic insights into how local regulators help to carry it out.

Expected Outcomes

When completed, the project will overturn the binary view of either Sec61-coupled translation on the ER surface vs. free cytosolic translation of all the other organellar proteins.

Instead, I will uncover a holistic picture of multiple proximal translation locales with distinct regulation. I aim to discover new connections between the two fundamental processes of protein synthesis and organelle biogenesis and thus make a ground-breaking advance in the understanding of how cells coordinate their architecture and functions.