Human Protein N-terminal Acetyltransferase hNaa50p (hNAT5/hSAN) Follows Ordered Sequential Catalytic Mechanism

Evjenth, Rune; Brenner, Annette K.; Thompson, Paul R.; Arnesen, Thomas; Frøystein, Nils Åge

doi:10.1074/jbc.m111.326587

Cited by 23 publications

(26 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From these data, it is concluded that the contribution of the peptide toward the thermal stability of Naa50 is independent of CoA. This is in contrast to the observations made in an NMR study where they did not notice any chemical shift changes upon addition of substrate alone (29). Because there is a correlation between the biochemical data and thermal shift assays, we believe that substrate alone could bind to the enzyme without the assistance of AcCoA/CoA.…”

Section: Resultscontrasting

confidence: 72%

“…1d). This explains why there were no chemical shifts noted in the previous NMR study when substrate peptide was added to the enzyme in the absence of cofactor (29).…”

Section: Resultsmentioning

confidence: 87%

“…Transcriptome analysis of eight different human cell lines for all 10 genes that make up different NAT complexes suggests that a few are expressed in all cell types, whereas others are specific. Note that Naa50 is also called San, NAT5, Naa50p, and NAT13 (5,23,29).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Human Naa50 Protein Displays Broad Substrate Specificity for Amino-terminal Acetylation

Reddi¹,

Saddanapu²,

Chinthapalli

et al. 2016

Journal of Biological Chemistry

View full text Add to dashboard Cite

Amino-terminal acetylation is a critical co-translational modification of the newly synthesized proteins in a eukaryotic cell carried out by six amino-terminal acetyltransferases (NATs). All NATs contain at least one catalytic subunit, and some contain one or two additional auxiliary subunits. For example, NatE is a complex of Naa10, Naa50, and Naa15 (auxiliary). In the present study, the crystal structure of human Naa50 suggested the presence of CoA and acetylated tetrapeptide (AcMMXX) that have co-purified with the protein. Biochemical and thermal stability studies on the tetrapeptide library with variations in the first and second positions confirm our results from the crystal structure that a peptide with Met-Met in the first two positions is the best substrate for this enzyme. In addition, Naa50 acetylated all MXAA peptides except for MPAA. Transcriptome analysis of 10 genes that make up six NATs in humans from eight different cell lines suggests that components of NatE are transcribed in all cell lines, whereas others are variable. Because Naa10 is reported to acetylate all amino termini that are devoid of methionine and Naa50 acetylates all other peptides that are followed by methionine, we believe that NatE complex can be a major contributor for amino-terminal acetylation at the ribosome exit tunnel.Co-translational protein modifications are important biochemical events. Prominent among them are amino-terminal modifications such as methionine cleavage, acetylation, and myristoylation (1-3). Initiator methionine in eukaryotic proteins is removed co-translationally by the enzyme methionine aminopeptidase (MetAP) 3 when the second amino acid is small and uncharged (1). About 70% of the matured proteins do not retain their amino-terminal methionine (4). Similarly, about 90% of all newly synthesized cytosolic proteins undergo aminoterminal acetylation (5). Protein amino-terminal acetylation is carried out by six amino-terminal acetyltransferases (NATs) named sequentially NatA to NatF, classified based on substrate preference (6 -8). NatA acetylates the peptides with serine, alanine, threonine, cysteine, and valine on the amino termini that are formed after MetAP action at the ribosome exit tunnel (5, 9), whereas NatB acts on methionine followed by acidic residues in the second position (10, 11). NatC, NatE, and NatF act on methionine that is followed by hydrophobic amino acids like leucine, phenylalanine, isoleucine, and tryptophan (8, 10, 12, 13). Additionally, NatF also acetylates methionine that is followed specifically by a lysine (14). NatD acetylates the amino termini of Ser-Gly of histones H2A and H4 (15). Each of the NATs (NatA-NatF) is a complex of one or two of the enzymes labeled serially as Naa10, Naa20, Naa30, Naa40, Naa50, and Naa60 attached to one or two of the auxiliary proteins named Naa15, Naa25, Naa35, and Naa38 (7, 9). Some NATs are known to bind to the ribosome at the exit tunnel through their auxiliary subunits (11, 16). Protein amino-terminal acetylation has potential effects on cell ...

show abstract

Section: Resultscontrasting

confidence: 72%

“…1d). This explains why there were no chemical shifts noted in the previous NMR study when substrate peptide was added to the enzyme in the absence of cofactor (29).…”

Section: Resultsmentioning

confidence: 87%

See 1 more Smart Citation

Human Naa50 Protein Displays Broad Substrate Specificity for Amino-terminal Acetylation

Reddi¹,

Saddanapu²,

Chinthapalli

et al. 2016

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Naa50 is the catalytic acetyltransferase subunit of NatE, is expressed in several human cell lines, and has been shown to be associated with NatA in yeast (Gautschi et al, 2003), fruit fly (Williams et al, 2003) and humans (Arnesen et al, 2006a). Naa50 has a distinct substrate activity for Met followed by a hydrophobic amino acid in human and yeast (Polevoda et al, 1999; Evjenth et al, 2009, 2012) and has been claimed to possess ε-acetyltransferase activity towards K525 in β-tubulin (Chu et al, 2011) and histone 4 (Evjenth et al, 2009). Furthermore, hNaa50 has been shown to harbor autoacetylation activity on internal lysines (K34, K37 and K140) in vitro, modulating Naa50 substrate activity (Evjenth et al, 2009, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…Naa50 has a distinct substrate activity for Met followed by a hydrophobic amino acid in human and yeast (Polevoda et al, 1999; Evjenth et al, 2009, 2012) and has been claimed to possess ε-acetyltransferase activity towards K525 in β-tubulin (Chu et al, 2011) and histone 4 (Evjenth et al, 2009). Furthermore, hNaa50 has been shown to harbor autoacetylation activity on internal lysines (K34, K37 and K140) in vitro, modulating Naa50 substrate activity (Evjenth et al, 2009, 2012). However, a recent structural study on human Naa50 contradicts these findings.…”

Section: Introductionmentioning

confidence: 99%

The biological functions of Naa10 — From amino-terminal acetylation to human disease

Dörfel

Lyon

2015

Gene

View full text Add to dashboard Cite

N-terminal acetylation (NTA) is one of the most abundant protein modifications known, and the N-terminal acetyltransferase (NAT) machinery is conserved throughout all Eukarya. Over the past 50 years, the function of NTA has begun to be slowly elucidated, and this includes the modulation of protein–protein interaction, protein-stability, protein function, and protein targeting to specific cellular compartments. Many of these functions have been studied in the context of Naa10/NatA; however, we are only starting to really understand the full complexity of this picture. Roughly, about 40% of all human proteins are substrates of Naa10 and the impact of this modification has only been studied for a few of them. Besides acting as a NAT in the NatA complex, recently other functions have been linked to Naa10, including post-translational NTA, lysine acetylation, and NAT/KAT-independent functions. Also, recent publications have linked mutations in Naa10 to various diseases, emphasizing the importance of Naa10 research in humans. The recent design and synthesis of the first bisubstrate inhibitors that potently and selectively inhibit the NatA/Naa10 complex, monomeric Naa10, and hNaa50 further increases the toolset to analyze Naa10 function.

show abstract

N‐terminal modifications of cellular proteins: The enzymes involved, their substrate specificities and biological effects

2015

Self Cite

View full text Add to dashboard Cite

The vast majority of eukaryotic proteins are N-terminally modified by one or more processing enzymes. Enzymes acting on the very first amino acid of a polypeptide include different peptidases, transferases, and ligases. Methionine aminopeptidases excise the initiator methionine leaving the nascent polypeptide with a newly exposed amino acid that may be further modified. N-terminal acetyl-, methyl-, myristoyl-, and palmitoyltransferases may attach an acetyl, methyl, myristoyl, or palmitoyl group, respectively, to the α-amino group of the target protein N-terminus. With the action of ubiquitin ligases, one or several ubiquitin molecules are transferred, and hence, constitute the N-terminal modification. Modifications at protein N-termini represent an important contribution to proteomic diversity and complexity, and are essential for protein regulation and cellular signaling. Consequently, dysregulation of the N-terminal modifying enzymes is implicated in human diseases. We here review the different protein N-terminal modifications occurring co- or post-translationally with emphasis on the responsible enzymes and their substrate specificities.

show abstract

Human Protein N-terminal Acetyltransferase hNaa50p (hNAT5/hSAN) Follows Ordered Sequential Catalytic Mechanism

Cited by 23 publications

References 51 publications

Human Naa50 Protein Displays Broad Substrate Specificity for Amino-terminal Acetylation

Human Naa50 Protein Displays Broad Substrate Specificity for Amino-terminal Acetylation

The biological functions of Naa10 — From amino-terminal acetylation to human disease

N‐terminal modifications of cellular proteins: The enzymes involved, their substrate specificities and biological effects

Contact Info

Product

Resources

About