Current Methods of Post-Translational Modification Analysis and Their Applications in Blood Cancers

Abstract

Post-translational modifications (PTMs) add a layer of complexity to the proteome through the addition of biochemical moieties to specific residues of proteins, altering their structure, function and/or localization. Mass spectrometry (MS)-based techniques are at the forefront of PTM analysis due to their ability to detect large numbers of modified proteins with a high level of sensitivity and specificity. The low stoichiometry of modified peptides means fractionation and enrichment techniques are often performed prior to MS to improve detection yields. Immuno-based techniques remain popular, with improvements in the quality of commercially available modification-specific antibodies facilitating the detection of modified proteins with high affinity. PTM-focused studies on blood cancers have provided information on altered cellular processes, including cell signaling, apoptosis and transcriptional regulation, that contribute to the malignant phenotype. Furthermore, the mechanism of action of many blood cancer therapies, such as kinase inhibitors, involves inhibiting or modulating protein modifications. Continued optimization of protocols and techniques for PTM analysis in blood cancer will undoubtedly lead to novel insights into mechanisms of malignant transformation, proliferation, and survival, in addition to the identification of novel biomarkers and therapeutic targets. This review discusses techniques used for PTM analysis and their applications in blood cancer research.

Comparative Phosphoproteomic Profiling in the Prefrontal Cortex of Prenatally Stressed Male Offspring Rats

“…1b). Rats from the PS-S group had a significantly extended immobility time in the FST compared with the control rats using one-way ANOVA (F = 38.540 (3,31), p < 0.05, Fig. 1c).…”

“…The data are shown in Figure 1. The total distance of the OFT in the PS-S group compared to the control group was significantly decreased using one-way ANOVA (F = 24.729 (3,31), p < 0.05; Fig. 1b).…”

“…An effective strategy, which includes suitable methods for phosphopeptide enrichment and fractionation, is required for a successful mass spectrometry-based phosphoproteomic experiment. Modification-specific enrichment techniques, such as immobilized metal affinity chromatography (IMAC) [26], titanium dioxide [27], fractionation with strong cation exchange [28], off-gel isoelectric focusing [29], and high-pH reverse phase fractionation [28, 30] separate phosphorylated proteins/peptides from their unphosphorylated counterparts, reduce the sample complexity, and increase the quantification efficiency and reliability [31, 32]. Compared with conventional strong cation exchange [28] and off-gel isoelectric focusing [33], the advantages of improved protein sequence coverage, simplified sample processing, reduced sample losses, and a uniform peptide distribution makes high-pH reverse phase fractionation the better choice for proteomic analysis.…”

Unambiguous Identification of Glucose-Induced Glycation in mAbs and other Proteins by NMR Spectroscopy

“…PTMs are typically investigated by high performance liquid chromatography (HPLC) coupled to mass spectrometry (MS) either with bottom-up, top-down or middle-up approaches [4][5][6]. However, distinguishing two isobaric PTMs is often challenging due to the same mass.…”

E3 ubiquitin ligases in the acute leukemic signaling pathways

“…Protein translation modifications are one of the most important regulatory mechanisms for intracellular proteins, enabling cells to respond to changes in the internal and external environment through rapid and reversible modifications to the structure, function, and location of a specific protein. More than two hundred protein translation modifications have been discovered, including phosphorylation, methylation, acetylation, ubiquitination, to name a few, which play an important role in cell growth, metabolism, differentiation, apoptosis, and other processes (Dunphy et al, 2021). Ubiquitination refers to the covalent binding of ubiquitin to a target protein (Figure 1), a process that involves the synergistic action of three ubiquitin enzymes: E1 ubiquitin activating enzyme, E2 ubiquitin conjugating enzyme, and E3 ubiquitin ligase (Nandi et al, 2006).…”