Dataset Information

Naa30 is critically involved in maintaining mitochondrial and Golgi integrity

ABSTRACT: N-terminal acetylation is one of the most common protein modifications in eukaryotes, with emerging roles in regulating protein quality and stoichiometry and targeting and complex formation. The NatC complex is one of the three major N-terminal acetyltransferases (NATs). Here, we partially defined the in vivo human NatC Nt-acetylome by combining siNAA30 mediated knockdown with positional proteomics. We identified 51 human NatC substrates and expanded our current knowledge on the substrate repertoire of NatC which now includes proteins harboring Met-Leu, Met-Ile, Met-Phe, Met-Trp, Met-Tyr, Met-Trp, Met-Met, Met-His and Met-Lys N-termini. Next to cytosolic proteins, several organellar proteins were identified as NatC substrates. Interestingly, upon Naa30 depletion, the levels of several organellar proteins were reduced, in particular those of mitochondrial proteins. Further, knockdown of Naa30 induced the loss of membrane potential, clearing and fragmentation of mitochondria. Naa30 depletion also led to disassembly of the Golgi apparatus. However, Naa30 depletion did not affect ER morphology, endosome or peroxisome distribution or microtubule and actin cytoskeletal architecture, suggesting that the observed mitochondrial fragmentation and clearance and Golgi scattering are not due to general disruption of organelles or microtubules. In conclusion, NatC Nt-acetylates a large variety of cytosolic and organellar proteins and is essential for cis-Golgi integrity and mitochondrial function.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Skin

SUBMITTER: Jonathan Vandenbussche

LAB HEAD: Kris Gevaert

PROVIDER: PXD000930 | Pride | 2016-10-05

REPOSITORIES: Pride

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Dataset's files

Source:

			Action	DRS
	L21649_1914_PetraVD_siNaa30-A431_cytosol_28-32_1.RAW	Raw
	L21650_1914_PetraVD_siNaa30-A431_cytosol_28-32_2.RAW	Raw
	L21651_1914_PetraVD_siNaa30-A431_cytosol_28-32_3.RAW	Raw
	L21652_1914_PetraVD_siNaa30-A431_cytosol_28-32_4.RAW	Raw
	L21653_1914_PetraVD_siNaa30-A431_cytosol_28-32_5.RAW	Raw

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Publications

A Role for Human N-alpha Acetyltransferase 30 (Naa30) in Maintaining Mitochondrial Integrity.

Van Damme Petra P Kalvik Thomas V TV Starheim Kristian K KK Jonckheere Veronique V Myklebust Line M LM Menschaert Gerben G Varhaug Jan Erik JE Gevaert Kris K Arnesen Thomas T

Molecular & cellular proteomics : MCP 20160930 11

N-terminal acetylation (Nt-acetylation) by N-terminal acetyltransferases (NATs) is one of the most common protein modifications in eukaryotes. The NatC complex represents one of three major NATs of which the substrate profile remains largely unexplored. Here, we defined the in vivo human NatC Nt-acetylome on a proteome-wide scale by combining knockdown of its catalytic subunit Naa30 with positional proteomics. We identified 46 human NatC substrates, expanding our current knowledge on the substra ...[more]

PMID: 27694331

Similar Datasets

Project description:Co-translational N-terminal (Nt-) acetylation of nascent polypeptides is catalyzed by N-terminal acetyltransferases (NATs). The very N-terminal amino acid sequence is the major factor determining whether or not a given protein is Nt-acetylated. In humans, six different NATs, denoted NatA-NatF, are identified. In the current study we used N-terminal COFRADIC analysis to define the in vivo substrate specificity of Naa50 (Nat5)/NatE as this has long remained elusive. Three yeast strains were generated; a control strain endogenously expressing yNaa50, a deletion strain depleted of yNaa50 and a strain deleted of yNaa50 but ectopically expressing human Naa50. When comparing the Nt-acetylation status of different N-termini in the control strain with the deletion strain, a reduction in Nt-acetylation for several yeast proteins was observed. To our surprise, these substrates were not of the predicted NatE-type substrates, but rather canonical NatA substrates. Further, ectopic expression of hNaa50 mainly resulted in the Nt-acetylation of a selected class of otherwise Nt-free yeast N-termini besides increasing the degree of Nt-acetylation of several other yeast proteins, and as such (partially) complementing those N-termini displaying reduced Nt-acetylation upon yNAA50-deletion. The preferred substrates of hNaa50 were predominantly Met-starting N-termini including Met-Lys-, Met-Val-, Met-Ala-, Met-Tyr-, Met-Phe-, Met-Leu-, Met-Ser- and Met-Thr, and highly overlapped with the previously identified human Naa60/NatF substrate specificity profile. Identification of several hNaa50 substrates with a small amino acid in the second position also revealed a potential interplay between the NATs and methionine aminopeptidases (MetAPs). The initiator Methionine (iMet) is normally cleaved off by MetAPs when the second amino acid is small, but our in vitro data suggest that in contrast to a free iMet, an Nt-acetylated iMet is not hydrolyzed by MetAPs. Thus, Naa50-mediated Nt-acetylation may potentially act as a mechanism to retain the iMet of proteins with a small amino acid at the second position that normally would be hydrolyzed.