Affinage

NAA60

N-alpha-acetyltransferase 60 · UniProt Q9H7X0

Length
242 aa
Mass
27.5 kDa
Annotated
2026-06-10
14 papers in source corpus 9 papers cited in narrative 9 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 5/5 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

NAA60 (NatF/HAT4) is an N-terminal acetyltransferase that post-translationally Nt-acetylates Met-starting protein N-termini, with a substrate preference for the cytosol-facing N-termini of transmembrane proteins in the secretory pathway (PMID:21750686, PMID:25732826). It anchors as a peripheral membrane protein to the cytosolic face of Golgi membranes through two C-terminal amphipathic helices that fold only upon membrane contact and bind preferentially to PI(4)P-rich membranes, accounting for its medial/trans-Golgi residency among golgins and GRASP proteins (PMID:28196861, PMID:39965656). Crystal structures define a GNAT catalytic fold using Tyr97 and His138 as key catalytic residues, and the enzyme additionally displays lysine Nε-acetyltransferase activity toward free histone H4 at K79 and K91 (PMID:21981917, PMID:27550639). Through Nt-acetylation of transmembrane substrates including the phosphate importer SLC20A2/PiT2 and the volume-regulated anion channel subunits LRRC8A and LRRC8D, NAA60 controls their surface trafficking, thereby governing extracellular phosphate uptake and cellular uptake of platinum-based drugs (PMID:38480682, PMID:41053424). Loss of NAA60 causes Golgi fragmentation and chromosome segregation defects (PMID:21750686, PMID:25732826), and biallelic loss-of-function variants cause autosomal recessive primary familial brain calcification via disrupted Nt-acetylation-dependent surface trafficking and phosphate homeostasis (PMID:38480682, PMID:39229657).

Mechanistic history

Synthesis pass · year-by-year structured walk · 8 steps
  1. 2011 High

    Established that NAA60 is a bona fide N-terminal acetyltransferase with a distinct substrate preference for Met-starting N-termini, defining a new NAT (NatF) and linking it to chromosome segregation.

    Evidence In vitro peptide library acetylation with purified recombinant human and Drosophila enzyme, ectopic expression in yeast with N-terminal COFRADIC, and RNAi knockdown in Drosophila cells

    PMID:21750686

    Open questions at the time
    • Subcellular site of activity not yet defined
    • Physiological transmembrane substrates not identified
    • Mechanism linking loss to segregation defects unresolved
  2. 2011 Medium

    Showed NAA60 (HAT4) localizes to the Golgi and additionally acts as a lysine acetyltransferase toward free histone H4 at K79/K91, connecting it to nucleosome assembly and cell survival.

    Evidence Immunofluorescence, in vitro acetyltransferase assay with free histones, and siRNA knockdown with proliferation/DNA-damage/apoptosis readouts

    PMID:21981917

    Open questions at the time
    • How a Golgi-anchored enzyme accesses free histones unresolved
    • Relative physiological importance of KAT versus NAT activity unclear
  3. 2015 High

    Resolved that NAA60 sits on the cytosolic face of Golgi membranes and selectively acetylates cytosol-facing transmembrane protein N-termini, and that its loss fragments the Golgi—tying the enzyme to organelle integrity.

    Evidence PROMPT membrane topology assay, selective permeabilization, N-terminal acetylome (COFRADIC) of knockdown cells, and Golgi morphology imaging

    PMID:25732826

    Open questions at the time
    • Membrane anchoring mechanism not yet defined
    • Causal link between substrate acetylation and Golgi integrity not established
  4. 2016 High

    Defined the catalytic architecture by solving Naa60 crystal structures and identifying Tyr97/His138 as catalytic residues plus a regulatory β3-β4 loop and an amphipathic helix for Golgi localization.

    Evidence X-ray crystallography with Ac-CoA/CoA, site-directed mutagenesis, and in vitro activity assays

    PMID:27550639

    Open questions at the time
    • Structure of the membrane-bound enzyme not captured
    • Regulatory function of the β3-β4 loop not mechanistically resolved
  5. 2017 High

    Explained how NAA60 reaches the Golgi: two C-terminal amphipathic helices fold on membrane contact and bind with strong preference for PI(4)P, defining a lipid-dependent post-translational anchoring mode.

    Evidence Computational modeling, in vitro liposome binding assays, and cellular mutational analysis of helix hydrophobic face with localization readout

    PMID:28196861

    Open questions at the time
    • Regulation of membrane targeting in vivo unclear
    • Whether lipid binding modulates catalytic activity not addressed
  6. 2024 High

    Connected NAA60 to human disease and to phosphate physiology by showing biallelic loss-of-function causes primary familial brain calcification and that NAA60 Nt-acetylates SLC20A2 to control its surface levels and phosphate uptake.

    Evidence Patient variant functional analysis, in vitro Nt-acetylation with SLC20A2, cell surface biotinylation, and phosphate uptake assays in NAA60-deficient cells

    PMID:38480682 PMID:39229657

    Open questions at the time
    • Precise mechanism linking acetylation to trafficking not fully defined
    • Role of additional calcification-associated substrates (e.g., XPR1, RFC) not mechanistically resolved
  7. 2025 Medium

    Mapped the NAA60 proximal interactome to the medial/trans-Golgi, enriched for golgins and GRASP proteins, refining its suborganellar position relative to Golgi-integrity machinery.

    Evidence BioID proximity labeling with streptavidin purification and mass spectrometry, plus suborganellar localization analysis

    PMID:39965656

    Open questions at the time
    • Direct versus proximal interactions not distinguished
    • Functional significance of golgin/GRASP proximity untested
  8. 2025 Medium

    Extended NAA60 substrate scope and clinical relevance by showing it acetylates LRRC8A/D N-termini to enable cellular uptake of platinum drugs, with loss conferring drug resistance.

    Evidence NAA60 knockout cells, in vitro Nt-acetylation, drug uptake and sensitivity assays, and charge-mimic N-terminal mutagenesis of LRRC8A/D

    PMID:41053424

    Open questions at the time
    • Single lab; reciprocal in vivo validation limited
    • Mechanism by which N-terminal acetylation alters channel function not resolved

Open questions

Synthesis pass · forward-looking unresolved questions
  • How NAA60-mediated N-terminal acetylation mechanistically controls transmembrane protein surface trafficking, and how its Golgi/histone activities are coordinated, remains unresolved.
  • No structure of the membrane-anchored enzyme engaging a transmembrane substrate
  • Mechanistic basis linking acetylation to trafficking competence unknown
  • Integration of cytosolic NAT activity with reported histone KAT activity unexplained

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0016740 transferase activity 6 GO:0140096 catalytic activity, acting on a protein 4 GO:0008289 lipid binding 1
Localization
GO:0005794 Golgi apparatus 4
Pathway
R-HSA-392499 Metabolism of proteins 3 R-HSA-1643685 Disease 2

Evidence

Reading pass · 9 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2011 NAA60 (NatF/hNaa60) is an N-terminal acetyltransferase (NAT) with activity targeting Met-Lys- and other Met-starting protein N-termini, as demonstrated by in vitro peptide library acetylation assays using purified recombinant human and Drosophila homologues. In vivo, ectopic expression of hNaa60p in yeast acetylated distinct Met-starting yeast protein N-termini and increased general N-terminal acetylation levels. Knockdown of NAA60 in Drosophila cells induced chromosomal segregation defects. In vitro peptide library acetylation assay with purified recombinant protein; ectopic expression in yeast followed by N-terminal COFRADIC; RNAi knockdown in Drosophila cells PLoS genetics High 21750686
2011 HAT4 (NAA60) localizes to the Golgi apparatus and functions as a B-type histone acetyltransferase that preferentially acetylates free (non-nucleosomal) histone H4 at lysine residues K79 and K91 in the globular domain. HAT4 depletion impaired nucleosome assembly, inhibited cell proliferation, sensitized cells to DNA damage, and induced apoptosis. Subcellular localization by immunofluorescence; in vitro acetyltransferase assay with free histones; siRNA knockdown with cell proliferation, DNA damage, and apoptosis readouts Molecular cell Medium 21981917
2015 NAA60 (Naa60/NatF) localizes exclusively to the cytosolic face of Golgi membranes (established by a new membrane topology assay PROMPT and selective membrane permeabilization). NAA60 specifically acetylates N-termini of transmembrane proteins that face the cytosol, as revealed by Nt-acetylome analysis of NAA60-knockdown cells. NAA60 knockdown causes Golgi fragmentation, indicating a role in maintaining Golgi structural integrity. Membrane topology assay (PROMPT); selective membrane permeabilization; N-terminal acetylome (COFRADIC) analysis of knockdown cells; immunofluorescence of Golgi morphology in knockdown cells Cell reports High 25732826
2016 Crystal structures of human Naa60 in complex with Ac-CoA or CoA reveal a GNAT domain followed by an amphipathic helix contributing to Golgi localization. Structural and biochemical studies identified Tyr97 and His138 as key catalytic residues, and Phe34 as influencing cofactor positioning. The non-conserved β3-β4 long loop participates in regulation of hNaa60 activity. Naa60 also harbors lysine Nε-acetyltransferase (KAT) activity toward histone H4 lysine residues. X-ray crystallography; site-directed mutagenesis; in vitro acetyltransferase activity assays Scientific reports High 27550639
2017 The C-terminal tail of Naa60 anchors it to the Golgi as a peripheral membrane protein via two amphipathic helices that fold into α-helical conformations only in the presence of liposomes and bind membranes in a parallel orientation via hydrophobic and electrostatic interactions. Naa60 shows strong and specific binding preference for phosphatidylinositol PI(4)P-containing membranes, consistent with its primary Golgi residency. Mutational analysis confirmed the hydrophobic face of these helices is critical for membranous localization. Golgi anchoring is proposed to occur post-translationally. Computational modeling; in vitro liposome binding assays; cellular mutational analysis with localization readout by immunofluorescence The Journal of biological chemistry High 28196861
2024 Biallelic loss-of-function variants in NAA60 cause autosomal recessive primary familial brain calcification (PFBC) with absent Nt-acetylation activity. In vitro, the phosphate importer SLC20A2 (PiT2) was identified as a direct substrate of NAA60 Nt-acetylation. In cells, NAA60 loss reduced surface levels of SLC20A2 and decreased extracellular phosphate uptake, linking NAA60-mediated Nt-acetylation of transmembrane proteins to phosphate homeostasis. In vitro Nt-acetylation assay with SLC20A2 as substrate; cell surface biotinylation assay; phosphate uptake assay in NAA60-deficient cells; patient variant functional analysis Nature communications High 38480682
2024 A homozygous frameshift variant in NAA60 disrupts its Golgi localization and accelerates protein degradation. The mutant NAA60 alters interaction with PFBC-related proteins PiT2 (SLC20A2) and XPR1, affecting intracellular phosphate homeostasis. NAA60 KO in cells also caused decreased expression of multiple brain calcification-associated membrane proteins including RFC (reduced folate carrier), a folate metabolism protein. Immunofluorescence (Golgi localization); Western blot (protein stability); co-immunoprecipitation (interaction with PiT2/XPR1); mass spectrometry in NAA60 KO cell lines; gene knockout cell lines Movement disorders : official journal of the Movement Disorder Society Medium 39229657
2025 BioID proximity labeling of NAA60 identified over 100 proximal partners enriched on the trans-side of the Golgi, including golgins and GRASP proteins essential for Golgi integrity. Suborganellar localization analysis revealed a more prominent medial/trans-Golgi localization of NAA60. Biotinylated peptide analysis was used to infer the topology of transmembrane protein interactors in the secretory pathway. BioID proximity labeling; streptavidin affinity purification; mass spectrometry; suborganellar localization analysis Open biology Medium 39965656
2025 NAA60 facilitates cellular uptake of platinum-based drugs (cis- and carboplatin) by acetylating the N-termini of LRRC8A and LRRC8D (volume-regulated anion channel subunits). Loss of NAA60 decreases drug uptake and causes drug resistance. Introduction of positively charged amino acids at the N-termini of LRRC8A/D (mimicking absence of the acetyl group) similarly decreased platinum sensitivity, functionally validating the role of N-terminal acetylation at these sites. NAA60 knockout cells; in vitro N-terminal acetylation assay; drug uptake assay; site-directed mutagenesis of LRRC8A/D N-termini; drug sensitivity assays in BRCA1;p53-deficient cells and tumors Communications biology Medium 41053424

Source papers

Stage 0 corpus · 14 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2011 NatF contributes to an evolutionary shift in protein N-terminal acetylation and is important for normal chromosome segregation. PLoS genetics 161 21750686
2015 An organellar nα-acetyltransferase, naa60, acetylates cytosolic N termini of transmembrane proteins and maintains Golgi integrity. Cell reports 107 25732826
2011 HAT4, a Golgi apparatus-anchored B-type histone acetyltransferase, acetylates free histone H4 and facilitates chromatin assembly. Molecular cell 67 21981917
2024 Biallelic NAA60 variants with impaired n-terminal acetylation capacity cause autosomal recessive primary familial brain calcifications. Nature communications 41 38480682
2019 NATF (Native and Tissue-Specific Fluorescence): A Strategy for Bright, Tissue-Specific GFP Labeling of Native Proteins in Caenorhabditis elegans. Genetics 39 30952669
2017 Molecular determinants of the N-terminal acetyltransferase Naa60 anchoring to the Golgi membrane. The Journal of biological chemistry 36 28196861
2016 Structure and function of human Naa60 (NatF), a Golgi-localized bi-functional acetyltransferase. Scientific reports 30 27550639
2011 Histone H4 lysine 14 acetylation in Leishmania donovani is mediated by the MYST-family protein HAT4. Microbiology (Reading, England) 22 22016570
2016 Histone acetyltransferase HAT4 modulates navigation across G2/M and re-entry into G1 in Leishmania donovani. Scientific reports 18 27272906
2020 Extended Venous Thromboembolism Prophylaxis in Medically Ill Patients: An NATF Anticoagulation Action Initiative. The American journal of medicine 17 32362349
2024 A Homozygous Variant in NAA60 Is Associated with Primary Familial Brain Calcification. Movement disorders : official journal of the Movement Disorder Society 8 39229657
2022 NAA60 (HAT4): the newly discovered bi-functional Golgi member of the acetyltransferase family. Clinical epigenetics 5 36539894
2025 Proximal partners of the organellar N-terminal acetyltransferase NAA60: insights into Golgi structure and transmembrane protein topology. Open biology 4 39965656
2025 NAA60 facilitates LRRC8A- and LRRC8D-mediated platinum drug uptake. Communications biology 0 41053424

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