Evaluating the Conformation and Binding Interface of Cap-Binding Proteins and Complexes via Ultraviolet Photodissociation Mass Spectrometry

O’Brien, John P.; Mayberry, Laura K.; Murphy, Patricia A.; Browning, Karen S.; Brodbelt, Jennifer S.

doi:10.1021/pr400869u

Cited by 10 publications

(31 citation statements)

References 81 publications

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“…A constitutively reduced mutant (C113S) and oxidized forms of eIF4E bound m 7 GTP with a modest 1.5x difference in k off values in NMR (nuclear magnetic resonance) solution studies (Monzingo et al, 2007). Further studies using mass spectrometry and a lysine-specific chemical probe indicated structural changes occurred upon altering the redox state and support the hypothesis of a redox sensor or switch for eIF4E (O'Brien et al, 2013). It remains a tantalizing possibility that the oxidation state of eIF4E (and/or eIFiso4E) may modulate cap binding in a redox-sensing manner in plants during retrograde signaling from the chloroplast to nucleus or other processes that could regulate the level of translation in response to the redox state of the cell.…”

Section: The Cast Of Cap-binding Proteins: Eif4e Eifiso4e and 4ehpmentioning

confidence: 80%

Mechanism of Cytoplasmic mRNA Translation

Browning

Bailey‐Serres

2015

The Arabidopsis Book

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Protein synthesis is a fundamental process in gene expression that depends upon the abundance and accessibility of the mRNA transcript as well as the activity of many protein and RNA-protein complexes. Here we focus on the intricate mechanics of mRNA translation in the cytoplasm of higher plants. This chapter includes an inventory of the plant translational apparatus and a detailed review of the translational processes of initiation, elongation, and termination. The majority of mechanistic studies of cytoplasmic translation have been carried out in yeast and mammalian systems. The factors and mechanisms of translation are for the most part conserved across eukaryotes; however, some distinctions are known to exist in plants. A comprehensive understanding of the complex translational apparatus and its regulation in plants is warranted, as the modulation of protein production is critical to development, environmental plasticity and biomass yield in diverse ecosystems and agricultural settings.

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Section: The Cast Of Cap-binding Proteins: Eif4e Eifiso4e and 4ehpmentioning

confidence: 80%

Mechanism of Cytoplasmic mRNA Translation

Browning

Bailey‐Serres

2015

The Arabidopsis Book

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190

220

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“…There is also experimental evidence that the looped region around the Lys165 and Arg166 residues interacts with the mRNA cap. 53 UVPD of the holo -eIF4E (Figure 2) generated a wide variety of fragment ions that retained m 7 GTP (a subset of m 7 GTP-bound fragment ions is shown in Table S2). The UVPD fragmentation map of the eIF4E/m 7 GTP complex (8+) displays the backbone cleavage sites that lead to fragment ions that retain m 7 GTP (red cleavage marks in Figure 2C).…”

Section: Resultsmentioning

confidence: 99%

Characterization of Native Protein Complexes Using Ultraviolet Photodissociation Mass Spectrometry

et al. 2014

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Ultraviolet photodissociation (UVPD) mass spectrometry (MS) was used to characterize the sequences of proteins in native protein–ligand and protein–protein complexes and to provide auxiliary information about the binding sites of the ligands and protein–protein interfaces. UVPD outperformed collisional induced dissociation (CID), higher-energy collisional dissociation (HCD), and electron transfer dissociation (ETD) in terms of yielding the most comprehensive diagnostic primary sequence information about the proteins in the complexes. UVPD also generated noncovalent fragment ions containing a portion of the protein still bound to the ligand which revealed some insight into the nature of the binding sites of myoglobin/heme, eIF4E/m7GTP, and human peptidyl-prolyl cis–trans isomerase 1 (Pin1) in complex with the peptide derived from the C-terminal domain of RNA polymerase II (CTD). Noncovalently bound protein–protein fragment ions from oligomeric β-lactoglobulin dimers and hexameric insulin complexes were also produced upon UVPD, providing some illumination of tertiary and quaternary protein structural features.

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“…Despite that the two cysteines involved are strictly conserved in plant eIF4Es, suggesting that they may have some important biological role, affinity-binding assays under both reducing and oxidizing conditions showed that in both cases wheat eIF4E retained the ability to bind the cap (Monzingo et al, 2007). However, further studies using mass spectrometry and a Lys-specific chemical probe indicated structural changes upon altering the redox state, supporting the hypothesis of a redox sensor or switch for eIF4E (O'Brien et al, 2013). Whether the oxidation state of eIF4E may modulate cap binding in a redox-sensing manner in plants and regulate the level of translation in response to the redox state of the cell remains uncertain.…”

Section: Peculiarities Of the Plant Eif4e-eif4g 1003-1092 Complexmentioning

confidence: 91%

Structure of eIF4E in Complex with an eIF4G Peptide Supports a Universal Bipartite Binding Mode for Protein Translation

et al. 2017

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The association-dissociation of the cap-binding protein eukaryotic translation initiation factor 4E (eIF4E) with eIF4G is a key control step in eukaryotic translation. The paradigm on the eIF4E-eIF4G interaction states that eIF4G binds to the dorsal surface of eIF4E through a single canonical alpha-helical motif, while metazoan eIF4E-binding proteins (m4E-BPs) advantageously compete against eIF4G via bimodal interactions involving this canonical motif and a second noncanonical motif of the eIF4E surface. Metazoan eIF4Gs share this extended binding interface with m4E-BPs, with significant implications on the understanding of translation regulation and the design of therapeutic molecules. Here we show the high-resolution structure of melon (Cucumis melo) eIF4E in complex with a melon eIF4G peptide and propose the first eIF4E-eIF4G structural model for plants. Our structural data together with functional analyses demonstrate that plant eIF4G binds to eIF4E through both the canonical and noncanonical motifs, similarly to metazoan eIF4E-eIF4G complexes. As in the case of metazoan eIF4E-eIF4G, this may have very important practical implications, as plant eIF4E-eIF4G is also involved in a significant number of plant diseases. In light of our results, a universal eukaryotic bipartite mode of binding to eIF4E is proposed.The initiation of protein synthesis is a key control and highly regulated step in eukaryotic gene expression (Sonenberg and Hinnebusch, 2009). Translation initiation leads to the assembly of the large (60S) and small (40S) ribosomal subunits into an active 80S ribosome that is able to locate the correct start codon of the mRNA molecule. This is facilitated by the coordinated actions of at least 12 protein initiation factors (Browning, 2004;Jackson et al., 2010;Hinnebusch, 2011;Hinnebusch and Lorsch, 2012; Browning and BaileySerres, 2015). In cap-dependent translation, binding of the eukaryotic translation initiation factor 4F (eIF4F) to the 7-methyl guanosine cap (m 7 G cap) at the 59 end of mRNA drives the attachment of the mRNA to the ribosomal 43S preinitiation complex. In mammals, eIF4F is built by three proteins: the mRNA 59 cap binding protein eIF4E, the RNA helicase eIF4A, and the scaffolding protein eIF4G, which contains binding domains for eIF4E, eIF4A, eIF3, and poly(A)-binding protein (PABP; Marcotrigiano et al., 1997;Pestova et al., 2001;Gross et al., 2003). In plants, purified eIF4F heterodimers contain eIF4E and eIF4G (Hinnebusch and Lorsch, 2012); plant eIF4A appears to be loosely associated and is therefore easily lost during purification (Lax et al., 1986). EIF4G associates with eIF3, recruiting the 40S subunit of the ribosome and initiating scanning of the mRNA in the 59 to 39 direction (Jackson et al., 2010;Park et al., 2011). EIF4G additionally binds simultaneously to eIF4E and PABP, the latter being able to interact with the mRNA poly(A) tail (Aitken and Lorsch, 2012; Browning and BaileySerres, 2015), resulting in a transient circularization of the mRNA.Higher plants contain an addit...

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Evaluating the Conformation and Binding Interface of Cap-Binding Proteins and Complexes via Ultraviolet Photodissociation Mass Spectrometry

Cited by 10 publications

References 81 publications

Mechanism of Cytoplasmic mRNA Translation

Mechanism of Cytoplasmic mRNA Translation

Characterization of Native Protein Complexes Using Ultraviolet Photodissociation Mass Spectrometry

Structure of eIF4E in Complex with an eIF4G Peptide Supports a Universal Bipartite Binding Mode for Protein Translation

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