Translation in all organisms is performed by the ribosome, one of the most ancient and universally conserved molecular machines. Termination is the last step of protein synthesis, which ensures that expressed proteins have lengths strictly defined by the corresponding open reading frames. This critical step should be accurate and efficient to prevent accumulation of truncated or overly long polypeptide products that can be toxic to cell. Whereas most steps of translation and corresponding extraribosomal factors (e.g. elongation factors) are highly conserved between bacteria and eukaryotes, the termination of translation is not. In human, premature termination is associated with a large number of genetic diseases. These unique features place termination as a promising target for development of drugs. A detailed understanding of bacterial translation termination may provide us with tools to develop antibacterial drugs. Elucidation of the molecular mechanism of eukaryotic termination is necessary to design or search for therapeutics to target human neurological diseases linked to premature termination. In this proposal, we will gain insights into molecular mechanisms of termination in both bacteria and eukaryotes.
In Aim 1, we will determine crystal structures of intermediate conformational steps of termination on the bacterial 70S ribosome. This will provide insights into how a remarkable accuracy is achieved by bacterial release factors RF1 and RF2.
In Aim 2, we will study termination on the eukaryotic 80S ribosome. Here, essential class I release factor eRF1 and class II release factor eRF3 are involved, which are structurally distinct from their bacterial counterparts.
In Aim 3, we will explore new therapeutic routes against diseases caused by premature termination. The long-term goals of our studies are to gain detailed mechanistic insights into key cellular processes involving translation, and to contribute to therapeutics development.

Public Health Relevance

Translation termination is an essential cellular process, defining the lengths of all expressed proteins. The proposed research will elucidate the molecular mechanism of termination. This understanding may pave the way for developing new classes of antibiotics and therapeutics against genetic diseases linked to premature termination.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM107465-04
Application #
9390479
Study Section
Macromolecular Structure and Function B Study Section (MSFB)
Program Officer
Flicker, Paula F
Project Start
2015-01-01
Project End
2018-11-30
Budget Start
2017-12-01
Budget End
2018-11-30
Support Year
4
Fiscal Year
2018
Total Cost
Indirect Cost
Name
University of Massachusetts Medical School Worcester
Department
Genetics
Type
Schools of Medicine
DUNS #
603847393
City
Worcester
State
MA
Country
United States
Zip Code
01655
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