Functional mapping of N-terminal residues in the yeast proteome uncovers novel determinants for mitochondrial protein import - Archive ouverte HAL Accéder directement au contenu
Pré-Publication, Document De Travail Année : 2022

Functional mapping of N-terminal residues in the yeast proteome uncovers novel determinants for mitochondrial protein import

S Nashed
  • Fonction : Auteur
M Benchouaia
  • Fonction : Auteur
A Dijoux-Maréchal
  • Fonction : Auteur
N Ruiz Gutierrez
  • Fonction : Auteur
L Gaulier
  • Fonction : Auteur
G Chevreux
  • Fonction : Auteur
B Palancade
  • Fonction : Auteur
F Devaux
  • Fonction : Auteur
E Laine
  • Fonction : Auteur
M Garcia
  • Fonction : Auteur

Résumé

ABSTRACT N-terminal ends of polypeptides are critical for the selective co-translational recruitment of N-terminal modification enzymes. However, it is unknown whether specific N-terminal signatures differentially regulate protein fate according to their cellular functions. In this work, we developed an in-silico approach to detect functional preferences in cellular N-terminomes, and identified in S. cerevisiae more than 200 Gene Ontology terms with specific N-terminal signatures. In particular, we discovered that Mitochondrial Targeting Sequences (MTS) show a strong and specific over-representation at position 2 of hydrophobic residues known to define potential substrates of the N-terminal acetyltransferase NatC. We validated mitochondrial precursors as co-translational targets of NatC by selective purification of translating ribosomes, and found that their N-terminal signature is conserved in Saccharomycotina yeasts. Finally, systematic mutagenesis of the position 2 in a prototypal yeast mitochondrial protein confirmed its critical role in mitochondrial protein import. Our work highlights the hydrophobicity of MTS N-terminal residues and their modification by NatC as critical features for the definition of the mitochondrial proteome, providing a molecular explanation for mitochondrial defects observed in yeast or human NatC-depleted cells. Functional mapping of N-terminal residues thus has the potential to support the discovery of novel mechanisms of protein regulation or targeting.

Dates et versions

hal-03789894 , version 1 (27-09-2022)

Identifiants

Citer

S Nashed, H El Barbry, M Benchouaia, A Dijoux-Maréchal, N Ruiz Gutierrez, et al.. Functional mapping of N-terminal residues in the yeast proteome uncovers novel determinants for mitochondrial protein import. 2022. ⟨hal-03789894⟩
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