| 2003 |
PrmC/HemK crystal structure resolved at 2.2 Å; the C-terminal domain adopts a canonical AdoMet-dependent methyltransferase fold; the conserved NPPY motif positions the glutamine substrate via hydrogen bonds orienting the nitrogen lone pair toward the AdoMet methyl group, establishing the N5-glutamine methylation catalytic mechanism. |
X-ray crystallography with substrate and product complexes; active-site structural analysis |
Biochemistry |
High |
12741815
|
| 2005 |
E. coli PrmC methylates the glutamine residue in the GGQ motif of release factor RF1; crystal structure of the RF1–PrmC–AdoHCy complex shows both domain 3 (GGQ domain) and central domains 2/4 of RF1 contact PrmC; methylation stimulates peptide chain release activity of RF1. |
X-ray crystallography of RF1–PrmC complex; methylation assays; site-directed mutagenesis |
Molecular cell |
High |
16364916
|
| 2005 |
Chlamydia trachomatis PrmC functions as an N5-glutamine AdoMet-dependent methyltransferase that methylates class I release factors at the GGQ motif; chlamydial PrmC can complement an E. coli prmC knockout in vivo. |
Complementation assay in E. coli prmC knockout; in vivo and in vitro methylation assay with recombinant proteins; tryptic fragment analysis |
Journal of bacteriology |
Medium |
15629922
|
| 2006 |
Recombinant murine PRED28 (HEMK2) protein localizes to the nucleus but shows no detectable adenine DNA methyltransferase activity; N6-methyladenine is essentially absent from mammalian DNA (fewer than 10³ m6A per mouse genome). |
Subcellular localization by immunofluorescence/fractionation; in vitro methyltransferase activity assay; sensitive mass spectrometry detection of m6A in genomic DNA |
FEBS letters |
Medium |
16684535
|
| 2008 |
Human HEMK2 (with TRMT112 as partner) methylates human and yeast eRF1 in complex with eRF3 and GTP in vitro; the human HEMK2 catalytic subunit complements growth defect of yeast mtq2 deletion strains, confirming conserved eRF1 glutamine methyltransferase function. |
In vitro methylation assay with recombinant human HEMK2–TRMT112; yeast complementation of mtq2Δ |
FEBS letters |
High |
18539146
|
| 2016 |
Murine HEMK2 requires a GQX3R motif for glutamine methylation activity; HEMK2 methylates the Gln185 residue of eRF1 and at least 11 additional human protein domains in vitro; CHD5 and NUT are methylated by HEMK2 in HEK293 cells. |
Peptide SPOT array specificity profiling; in vitro methylation of recombinant protein domains; in-cell methylation assay with transfected substrates |
The Journal of biological chemistry |
High |
26797129
|
| 2019 |
Human HEMK2 (C21orf127), designated KMT9α, forms an obligate heterodimer with TRMT112 (KMT9β) and monomethylates lysine 12 of histone H4 (H4K12me1) in vitro and in vivo; crystal structure of KMT9 with SAH and H4K12me1 peptide reveals the structural basis for H4K12 recognition; KMT9 enriches at promoters of cell cycle regulator genes and is required for prostate cancer cell proliferation. |
In vitro histone methyltransferase assay; X-ray crystallography of KMT9–SAH–H4K12me1 peptide complex; ChIP-seq; siRNA knockdown with proliferation and cell cycle assays; xenograft mouse model |
Nature structural & molecular biology |
High |
31061526
|
| 2020 |
Crystal structures of HEMK2–TRMT112 bound to SAM and to SAH with methylglutamine reveal a specific pocket in HEMK2 that accommodates the substrate glutamine and catalyzes its methylation; mass spectrometry confirms eRF1 glutamine methylation, demonstrating dual (Gln and Lys) methyltransferase activity of HEMK2. |
X-ray crystallography (two structures); mass spectrometry-based methylation verification |
The Biochemical journal |
High |
32969463
|
| 2021 |
A biotinylated NTMT1 bisubstrate inhibitor (NAH-C3-GPKK analogue) pulls down the endogenous HemK2–TRMT112 complex from cell lysates, and the parent compound NAH-C3-GPKK potently inhibits HemK2–TRMT112 methyltransferase activity, representing the first reported potent inhibitor of this complex. |
Chemoproteomic pulldown with biotinylated probe; competitive biochemical inhibition assay |
ACS chemical biology |
Medium |
34192867
|
| 2024 |
HEMK2 prefers glutamine over lysine methylation at both peptide and protein levels; the eRF1 sequence is strongly preferred over H4K12; Q-methylation prefers a G-Q-X3-R context while K-methylation prefers S/T at the first position; SETD6, not HEMK2, is the primary H4K12me1 methyltransferase in DU145 prostate cancer cells (HEMK2 activity ~1000-fold lower than SETD6 on H4K12). |
Peptide SPOT array methylation; in vitro protein methylation assays; siRNA knockdown combined with mass spectrometry quantification of H4K12me1 in DU145 cells |
Protein science |
Medium |
38284488
|
| 2024 |
A bi-substrate KMT9 inhibitor (KMI169) targets both the SAM and substrate-binding pockets of KMT9, determined by structure-based drug design; KMI169 selectively downregulates KMT9 target genes involved in cell cycle regulation and impairs proliferation of castration- and enzalutamide-resistant prostate cancer cells. |
Structure-based drug design with co-crystal structures; biochemical selectivity profiling; cellular target engagement assays; gene expression analysis; proliferation assays |
Nature communications |
High |
38167811
|
| 2024 |
In Drosophila, HemK2 methylates eRF1 in germline cells; knockdown of hemK2 reduces eRF1 methylation and protein synthesis, induces ribosomal stalling and disome formation, activates No-Go Decay leading to mRNA degradation, and causes apoptosis during oogenesis; overexpression of a methylation-deficient eRF1 recapitulates these defects, establishing eRF1 as the primary functional substrate. |
Germline-specific RNAi knockdown; methylation assays; polysome profiling (disome detection); No-Go Decay pathway inhibition rescue; genetic epistasis with methylation-deficient eRF1 overexpression |
Development (Cambridge, England) |
High |
38881530
|
| 2025 |
KMT9 localizes to mitochondria of prostate cancer cells (but not other tumor cell types) and monomethylates DLAT (dihydrolipoamide transacetylase) at lysine 596; this methylation regulates pyruvate dehydrogenase complex (PDC) activity; KMT9 depletion reduces DLAT K596me1, impairs PDC activity and de novo lipogenesis, and inhibits prostate cancer cell proliferation in vitro and in vivo. |
Subcellular fractionation and mitochondrial localization assays; in vitro and in vivo methylation assays identifying DLAT K596; PDC activity assay; de novo lipogenesis measurement; siRNA knockdown; mouse xenograft model; patient tissue correlation |
Nature communications |
High |
39885202
|