N-myristoyltransferase 1 is essential in early mouse development (original) (raw)
Related papers
N-myristoyltransferase: Tracing Steps Backwards to Find a Way Forward
bioRxiv, 2020
N-myristoylation refers to the attachment of a 14-carbon fatty acid onto the N-terminal glycine residue of a target protein. The myristoylation reaction, catalyzed by N-myristoyltrasnferase (NMT), is essential for regulating cellular activities such as signal transduction, proliferation, migration, differentiation, and transformation. Although a considerable amount of research is performed on the overexpression of NMT in pathogenic conditions, a fundamental knowledge gap exists on the evolution of NMT and the functional impact of myristoylation for normal cellular development and functions. We performed evolutionary analyses of the NMT gene and found that most non-vertebrates harbor a single nmt gene and all vertebrates examined harbor two genes; nmt1 and nmt2. For the first time, we report that teleosts harbor two copies of nmt1, named nmt1a and nmt1b. We traced the evolutionary history of the chromosomal fragments hosting NMT1 and NMT2 in humans and found that NMT1 and NMT2 trace ...
Nature Communications, 2020
The promising drug target N-myristoyltransferase (NMT) catalyses an essential protein modification thought to occur exclusively at N-terminal glycines (Gly). Here, we present high-resolution human NMT1 structures co-crystallised with reactive cognate lipid and peptide substrates, revealing high-resolution snapshots of the entire catalytic mechanism from the initial to final reaction states. Structural comparisons, together with biochemical analysis, provide unforeseen details about how NMT1 reaches a catalytically competent conformation in which the reactive groups are brought into close proximity to enable catalysis. We demonstrate that this mechanism further supports efficient and unprecedented myristoylation of an N-terminal lysine side chain, providing evidence that NMT acts both as N-terminal-lysine and glycine myristoyltransferase.
Genome biology, 2004
We evaluated the evolutionary conservation of glycine myristoylation within eukaryotic sequences. Our large-scale cross-genome analyses, available as MYRbase, show that the functional spectrum of myristoylated proteins is currently largely underestimated. We give experimental evidence for in vitro myristoylation of selected predictions. Furthermore, we classify five membrane-attachment factors that occur most frequently in combination with, or even replacing, myristoyl anchors, as some protein family examples show.
Journal of Molecular Biology
N-myristoyltransferases (NMTs) catalyze protein myristoylation, a lipid modification crucial for cell survival and a range of pathophysiological processes. Originally thought to modify only N-terminal glycine α-amino groups (G-myristoylation), NMTs were recently shown to also modify lysine ε-amino groups (K-myristoylation). However, the clues ruling NMTdependent K-myristoylation and the full range of targets are currently unknown. Here we combine mass spectrometry, kinetic studies, in silico analysis, and crystallography to identify the specific features driving each modification. We show that direct interactions between the substrate's reactive amino group and the NMT catalytic base promote K-myristoylation but with poor efficiency compared to G-myristoylation, which instead uses a water-mediated interaction. We provide evidence of depletion of proteins with NMT-dependent Kmyristoylation motifs in humans, suggesting evolutionary pressure to prevent this modification in favor of G-myristoylation. In turn, we reveal that K-myristoylation may only result from post-translational events. Our studies finally unravel the respective paths towards Kmyristoylation or G-myristoylation, which rely on a very subtle tradeoff embracing the chemical landscape around the reactive group.
Myristoylation, an Ancient Protein Modification Mirroring Eukaryogenesis and Evolution
Trends in Biochemical Sciences, 2020
N-myristoylation (MYR) is a crucial fatty acylation catalyzed by N-myristoyltransferases (NMTs) that is likely to have appeared over two billion years ago. Proteome-wide approaches have now delivered an exhaustive list of substrates undergoing MYR across approximately 2% of any proteome, with constituents, several unexpected, associated with different membrane compartments. A set of <10 proteins conserved in eukaryotes probably represents the original set of N-myristoylated targets, marking major changes occurring throughout eukaryogenesis. Recent findings have revealed unexpected mechanisms and reactivity, suggesting competition with other acylations that are likely to influence cellular homeostasis and the steady state of the modification landscape. Here, we review recent advances in NMT catalysis, substrate specificity, and MYR proteomics, and discuss concepts regarding MYR during evolution. Lipidated proteins Plasma membranes (PMs) are composed of extrinsic and intrinsic proteins (52%) and lipids (40%), the latter sustaining the overall cellular architecture. Membrane-penetrating extrinsic proteins often possess covalently linked lipids, usually fatty acids, which allow the protein to contact other intra-and extracellular proteins [1]. Protein lipidation involves amides (i.e. N-αmyristoylation, MYR, see Glossary and glycosylphosphatidylinositol (GPI) anchors), thioesters (i.e. S-palmitoylation, PAL), and thioethers (i.e. isoprenylation and farnesylation) [2]. Of these, MYR is a frequent and conserved modification specific to eukaryotes that targets major cellular components. Mapping the proteins undergoing MYR has proven challenging due to their difficult handling characteristics and amphiphilic, chimeric nature. Recently, high-end technologies have allowed the first lipidated proteome, the myristoylome, to be described in detail in various organisms recapitulating the tree of life [3]. These and other studies on myristoylome composition and genesis have also revealed (i) an unexpected novel mechanism of action of Nmyristoyltransferase (NMT), (ii) NMT substrate selectivity, and (iii) the capacity of NMT to act on N-terminal lysines (Lys) as well as the usual glycines (Gly). This review highlights the series of groundbreaking discoveries that have recently significantly advanced our knowledge about this long-studied enzyme. This includes an overview of a new NMT catalytic mechanism, substrate specificity, and proteomics, and a discussion of how a reduced set of targets is closely related to eukaryogenesis and eukaryote evolution. How NMTs catalyze MYR with high selectivity NMTs are GNAT members closely related to Nα-acetyltransferases Seventy-four crystal structures have now revealed that the C-terminal 400 amino acid-long NMT catalytic core displays a conserved 3D GCN5-related N-acetyltransferase (GNAT) core. GNATs also include the catalytic subunits of Nα-acetyltransferases (NAAs) [4], with Naa10 being the closest to NMT as it modifies N-terminal Gly [5-7]. NMTs have two adjacent GNAT domains, most likely to have arisen through duplication of a Naa10-like GNAT domain [8]. Prokaryotes do not possess NMTs, which seem to have arisen as eukaryotes evolved from the last archaeal
N-myristoyltransferase in the leukocytic development processes
Cell and Tissue Research, 2011
The lipidic modification of proteins has recently been shown to be of immense importance, although many of the roles of these modifications remain as yet unidentified. One of such key modifications occurring on several proteins is the covalent addition of a 14-carbon long saturated fatty acid, a process termed myristoylation. Myristoylation can occur during both co-translational protein synthesis and posttranslationally, confers lipophilicity to protein molecules, and controls protein functions. The protein myristoylation process is catalyzed by the enzyme N-myristoyltransferase (NMT), which exists as two isoforms: NMT1 and NMT2. NMT1 is essential for growth and development, during which rapid cellular proliferation is required, in a variety of organisms. NMT1 is also reported to be elevated in many cancerous states, which also involve rapid cellular growth, albeit in an unwanted and uncontrolled manner. The delineation of myristoylation-dependent cellular functions is still in a state of infancy, and many of the roles of the myristoylated proteins remain to be established. The development of cells of the leukocytic lineage represents a phase of rapid growth and development, and we have observed that NMT1 plays a role in this process. The current review outlines the roles of NMT1 in the growth and differentiation of the cells of leukocytic origin. The described studies clearly demonstrate the roles of NMT1 in the regulation of the developmental processes of the leukocytes cells and provide a basis for further research with the aim of unraveling the roles of protein myristoylation in both cellular and physiological context.
J Mol Biol, 2002
Myristoylation by the myristoyl-CoA:protein N-myristoyltransferase (NMT) is an important lipid anchor modification of eukaryotic and viral proteins. Automated prediction of N-terminal N-myristoylation from the substrate protein sequence alone is necessary for large-scale sequence annotation projects but it requires a low rate of false positive hits in addition to a sufficient sensitivity.Our previous analysis of substrate protein sequence variability, NMT sequences and 3D structures has revealed motif properties in addition to the known PROSITE motif that are utilized in a new predictor described here. The composite prediction function (with separate ad hoc parameterization (a) for queries from non-fungal eukaryotes and their viruses and (b) for sequences from fungal species) consists of terms evaluating amino acid type preferences at sequences positions close to the N terminus as well as terms penalizing deviations from the physical property pattern of amino acid side-chains encoded in multi-residue correlation within the motif sequence. The algorithm has been validated with a self-consistency and two jack-knife tests for the learning set as well as with kinetic data for model substrates. The sensitivity in recognizing documented NMT substrates is above 95 % for both taxon-specific versions. The corresponding rate of false positive prediction (for sequences with an N-terminal glycine residue) is close to 0.5 %; thus, the technique is applicable for large-scale automated sequence database annotation. The predictor is available as public WWW-server with the URL http://mendel.imp.univie.ac.at/myristate/. Additionally, we propose a version of the predictor that identifies a number of proteolytic protein processing sites at internal glycine residues and that evaluates possible N-terminal myristoylation of the protein fragments.A scan of public protein databases revealed new potential NMT targets for which the myristoyl modification may be of critical importance for biological function. Among others, the list includes kinases, phosphatases, proteasomal regulatory subunit 4, kinase interacting proteins KIP1/KIP2, protozoan flagellar proteins, homologues of mitochondrial translocase TOM40, of the neuronal calcium sensor NCS-1 and of the cytochrome c-type heme lyase CCHL. Analyses of complete eukaryote genomes indicate that about 0.5 % of all encoded proteins are apparent NMT substrates except for a higher fraction in Arabidopsis thaliana (∼0.8 %).
Biochemistry, 1998
is an essential eukaryotic enzyme that catalyzes the cotranslational transfer of myristate to the NH 2 -terminal glycine residue of a number of important proteins of diverse function. Human NMT (hNMT) activity was found to be activated by L-histidine in a concentration-dependent manner. In contrast, two structural analogues of L-histidine, L-histidinol and histamine, inhibited hNMT activity in a noncompetitive manner with half-maximal inhibitions of 18 and 1.5 mM, respectively. The inhibition of hNMT activity by L-histidinol was reversed by a 2-fold molar excess of L-histidine, suggesting that L-histidine and L-histidinol were competing for a common site on NMT. Kinetic data indicated that whereas L-histidine enhanced the V max , both L-histidinol and histamine decreased the V max ; none of these compounds altered the K m . Our studies suggest that L-histidine and its analogues may be interacting with His-293, involved in myristoyl-CoA transfer, rather than His-218, and implicated in the transfer of myristoyl-CoA to the peptide substrates. Site-directed mutagenesis of His-293, Val-291, and Glu-290 resulted in proteins with no measurable NMT activity. The most conserved region in the catalytic domain EEVEH (289-293) is critical for the myristoyl-CoA transfer in the NMT-catalyzed reactions. This region will be useful for the design of regulators of NMT function.