Menu
MapConnectionsTopicsBulgariaThe Night (K-TRIO)Marie Skłodowska-CurieFor studentsFor teachersMethodologySurprise me
H2020Individual fellowship2018–2023

srpabsotcpfaaieps · Selective ribosome profiling and biochemistry studies on the co-translational protein folding and assembly in eukaryotic protein synthesis

Horizon 2020 — Marie Skłodowska-Curie Actions

Duration
2018-05-01 → 2023-09-01
EU contribution
€171,461
Participants
1
Scheme
MSCA-IF

Lines connect the coordinator with its partners.

Results in brief

Selective ribosome profiling and biochemistry studies on the co-translational protein folding and assembly in eukaryotic protein synthesis

The folding of newly synthesized proteins into the native state and the assembly of functional protein complexes are central features of every cell. Many of the critical steps of these processes occur co-translationally, during ongoing translation, and are assisted by molecular chaperones. Despite the importance of these processes, very little is known about the molecular mechanisms driving chaperone-assisted co-translational folding and assembly. The objective of this project was to dissect the chaperone network which assists in the folding of newly synthesized proteins during ongoing translation in cells of the model organism S. cerevisiae, and to correlate the action of this network with co-translational protein assembly. In particular, this project used a high throughput technology, termed ribosome profiling, to determine the interaction profiles of the major chaperones of yeast with the entire nascent proteome at all stages of translation. This knowledge was then used to correlate chaperone action with the process of subunit association driving co-translational assembly. The focus was on the chaperones of the yeast cytosol, Ssa1 and Ssb1, two homologs of the Hsp70 chaperone family, with their co-chaperones RAC, Ydj1 and Sis1, as well as on the yeast Hsp90, Hsc82. The results allowed us to reveal principles of functional networking of the chaperone machineries that promote the formation of correctly folded proteins. Intriguingly, the association of chaperones is tuned to the onset of co-translational assembly, suggesting a high degree of functional coordination. This fundamental research broadens our view on cellular organization and protein homeostasis. It establishes the basis for a rational understanding of protein biogenesis, thereby providing new opportunities for wider applications of the results for research, such as cell biology and synthetic biology, for understanding of protein folding diseases and for industry.

Data: CORDIS, © European Union

Project objective

Biological activity of cells depends on timely production of natively folded proteins by powerful translation and folding machineries. At a critical regulatory intersection of translation and folding, ribosomes act as integration hubs coordinating chaperone, enzyme and membrane targeting factor activity, influencing folding. Final assembly of proteins into oligomeric complexes however, has long been considered post-translational and dependent on random collision of fully synthesized diffusing subunits. In a shift of paradigm, recent evidence from the Bukau laboratory now suggests that in bacteria, assembly initiates co-translationally assisted by chaperones, and gene organization into operons drives co-localized translation of complex subunits that impacts efficiency of assembly. Fundamental differences in eukaryotes such as rarity of operons and differing chaperone constellations imply a widely different folding and assembly biology, which remains largely unexplored. The selective ribosome profiling (SeRP) method, developed by the Bukau lab, now allows ground breaking identification and definition of dynamic interactions of nascent chains, at near-residue resolution. Using SeRP with supporting biochemistry, I will unravel the nascent chain molecular biology underpinning protein folding and assembly in yeast, Saccharomyces cerevisiae, a powerful model for studying the fundamental aspects of this biology. Specifically, I will establish (1) basic features and prevalence of co-translational protein assembly, (2) how chaperones guide co-translational protein folding to affect assembly. Subunit interaction profiles complemented by chaperone interaction profiles, will expose the timing and interplay of protein folding and assembly steps linked to protein synthesis, establishing a detailed conceptually new biology of complex assembly in eukaryotes.

Original text from CORDIS.

Participants

  • RUPRECHT-KARLS-UNIVERSITAET HEIDELBERG · HeidelbergCoordinatorGermany

Links

Data: CORDIS, © European Union