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Cardiovascular Therapeutics 2024Endothelial-to-mesenchymal transition (EndMT) is the process by which endothelial cells lose their endothelial properties and acquire mesenchymal characteristics....
Endothelial-to-mesenchymal transition (EndMT) is the process by which endothelial cells lose their endothelial properties and acquire mesenchymal characteristics. Dual-specific protein phosphatase 22 (DUSP22) inactivates various protein kinases and transcription factors by dephosphorylating serine/threonine residues: hence, it plays a key role in many diseases. The aim of this study was to explore the functional role of DUSP22 in EndMT. In the transforming growth factor--induced EndMT model in human umbilical vein endothelial cells (HUVECs), we observed a downregulation of DUSP22 expression. This DUSP22 deficiency could aggravate EndMT. Conversely, the overexpression of DUSP22 could ameliorate EndMT. We used signaling pathway inhibitors to verify our results and found that DUSP22 could regulate EndMT through the smad2/3 and the mitogen-activated protein kinase (MAPK) signaling pathways. In summary, DUSP22 ameliorates EndMT in HUVECs in vitro through the smad2/3 and MAPK signaling pathways.
Topics: Humans; Down-Regulation; Dual-Specificity Phosphatases; Endothelial-Mesenchymal Transition; Human Umbilical Vein Endothelial Cells; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Phosphatases; Phosphoprotein Phosphatases
PubMed: 38495810
DOI: 10.1155/2024/5583961 -
Nature Communications Mar 2024Yeast Cadmium Factor 1 (Ycf1) sequesters glutathione and glutathione-heavy metal conjugates into yeast vacuoles as a cellular detoxification mechanism. Ycf1 belongs to...
Yeast Cadmium Factor 1 (Ycf1) sequesters glutathione and glutathione-heavy metal conjugates into yeast vacuoles as a cellular detoxification mechanism. Ycf1 belongs to the C subfamily of ATP Binding Cassette (ABC) transporters characterized by long flexible linkers, notably the regulatory domain (R-domain). R-domain phosphorylation is necessary for activity, whereas dephosphorylation induces autoinhibition through an undefined mechanism. Because of its transient and dynamic nature, no structure of the dephosphorylated Ycf1 exists, limiting understanding of this R-domain regulation. Here, we capture the dephosphorylated Ycf1 using cryo-EM and show that the unphosphorylated R-domain indeed forms an ordered structure with an unexpected hairpin topology bound within the Ycf1 substrate cavity. This architecture and binding mode resemble that of a viral peptide inhibitor of an ABC transporter and the secreted bacterial WXG peptide toxins. We further reveal the subset of phosphorylation sites within the hairpin turn that drive the reorganization of the R-domain conformation, suggesting a mechanism for Ycf1 activation by phosphorylation-dependent release of R-domain mediated autoinhibition.
Topics: Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Cadmium; ATP-Binding Cassette Transporters; Glutathione; Peptides
PubMed: 38493146
DOI: 10.1038/s41467-024-46722-w -
Cells Feb 2024Post-translational modifications (PTMs) are crucial mechanisms that underlie the intricacies of biological systems and disease mechanisms. This review focuses on the... (Review)
Review
Post-translational modifications (PTMs) are crucial mechanisms that underlie the intricacies of biological systems and disease mechanisms. This review focuses on the latest advancements in the design of heterobifunctional small molecules that hijack PTM machineries for target-specific modifications in living systems. A key innovation in this field is the development of proteolysis-targeting chimeras (PROTACs), which promote the ubiquitination of target proteins for proteasomal degradation. The past decade has seen several adaptations of the PROTAC concept to facilitate targeted (de)phosphorylation and acetylation. Protein fusion tags have been particularly vital in these proof-of-concept studies, aiding in the investigation of the functional roles of post-translationally modified proteins linked to diseases. This overview delves into protein-tagging strategies that enable the targeted modulation of ubiquitination, phosphorylation, and acetylation, emphasizing the synergies and challenges of integrating heterobifunctional molecules with protein tags in PTM research. Despite significant progress, many PTMs remain to be explored, and protein tag-assisted PTM-inducing chimeras will continue to play an important role in understanding the fundamental roles of protein PTMs and in exploring the therapeutic potential of manipulating protein modifications, particularly for targets not yet addressed by existing drugs.
Topics: Ubiquitination; Protein Processing, Post-Translational; Phosphorylation; Proteins
PubMed: 38474390
DOI: 10.3390/cells13050426 -
PloS One 2024Phosphatases can dephosphorylate phosphorylated kinases, leading to their inactivation, and ferroptosis is a type of cell death. Therefore, our aim is to identify...
Phosphatases can dephosphorylate phosphorylated kinases, leading to their inactivation, and ferroptosis is a type of cell death. Therefore, our aim is to identify phosphatases associated with ferroptosis by analyzing the differentially expressed genes (DEGs) of the Luminal A Breast Cancer (LumABC) cohort from the Cancer Genome Atlas (TCGA). An analysis of 260 phosphatase genes from the GeneCard database revealed that out of the 28 DEGs with high expression, only the expression of pyruvate dehydrogenase phosphatase 2 (PDP2) had a significant correlation with patient survival. In addition, an analysis of DEGs using gene ontology, Kyoto Encyclopedia of Genes and Genomes and gene set enrichment analysis revealed a significant variation in the expression of ferroptosis-related genes. To further investigate this, we analyzed 34 ferroptosis-related genes from the TCGA-LumABC cohort. The expression of long-chain acyl-CoA synthetase 4 (ACSL4) was found to have the highest correlation with the expression of PDP2, and its expression was also inversely proportional to the survival rate of patients. Western blot experiments using the MCF-7 cell line showed that the phosphorylation level of ACSL4 was significantly lower in cells transfected with the HA-PDP2 plasmid, and ferroptosis was correspondingly reduced (p < 0.001), as indicated by data from flow cytometry detection of membrane-permeability cell death stained with 7-aminoactinomycin, lipid peroxidation, and Fe2+. Immunoprecipitation experiments further revealed that the phosphorylation level of ACSL4 was only significantly reduced in cells where PDP2 and ACSL4 co-precipitated. These findings suggest that PDP2 may act as a phosphatase to dephosphorylate and inhibit the activity of ACSL4, which had been phosphorylated and activated in LumABC cells. Further experiments are needed to confirm the molecular mechanism of PDP2 inhibiting ferroptosis.
Topics: Female; Humans; Breast Neoplasms; Coenzyme A Ligases; Ferroptosis; Lipid Peroxidation; Phosphoric Monoester Hydrolases; Phosphorylation; Pyruvate Dehydrogenase (Lipoamide)-Phosphatase
PubMed: 38466744
DOI: 10.1371/journal.pone.0299571 -
Bioscience Reports Mar 2024Parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF23) control extracellular phosphate levels by regulating renal NPT2A-mediated phosphate transport by a...
Parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF23) control extracellular phosphate levels by regulating renal NPT2A-mediated phosphate transport by a process requiring the PDZ scaffold protein NHERF1. NHERF1 possesses two PDZ domains, PDZ1 and PDZ2, with identical core-binding GYGF motifs explicitly recognizing distinct binding partners that play different and specific roles in hormone-regulated phosphate transport. The interaction of PDZ1 and the carboxy-terminal PDZ-binding motif of NPT2A (C-TRL) is required for basal phosphate transport. PDZ2 is a regulatory domain that scaffolds multiple biological targets, including kinases and phosphatases involved in FGF23 and PTH signaling. FGF23 and PTH trigger disassembly of the NHERF1-NPT2A complex through reversible hormone-stimulated phosphorylation with ensuing NPT2A sequestration, down-regulation, and cessation of phosphate absorption. In the absence of NHERF1-NPT2A interaction, inhibition of FGF23 or PTH signaling results in disordered phosphate homeostasis and phosphate wasting. Additional studies are crucial to elucidate how NHERF1 spatiotemporally coordinates cellular partners to regulate extracellular phosphate levels.
Topics: Sodium-Hydrogen Exchangers; Ion Transport; Parathyroid Hormone; Biological Transport; Phosphates; Phosphoproteins
PubMed: 38465463
DOI: 10.1042/BSR20231380 -
Vavilovskii Zhurnal Genetiki I Selektsii Feb 2024Lipin-1 is a member of the evolutionarily conserved family of proteins and is expressed predominantly in adipose tissue and skeletal muscle. On the one hand, lipin-1 is...
Lipin-1 is a member of the evolutionarily conserved family of proteins and is expressed predominantly in adipose tissue and skeletal muscle. On the one hand, lipin-1 is an enzyme that catalyzes the dephosphorylation of phosphatidic acid to diacylglycerol (DAG) and thus participates in the metabolic pathways of biosynthesis of storage lipids in the cell, membrane phospholipids, and intracellular signaling molecules. On the other hand, lipin-1 is able to be transported from the cytoplasm to the nucleus and is a coactivator of lipid metabolism gene transcription. It was shown, using the analysis of single nucleotide polymorphism (SNP) associations, that the lipin-1 coding gene (LPIN1) is a promising candidate gene for milk production traits in Holstein and Brown Swiss cows. However, it is unclear how much of its effect depends on the breed. The Yaroslavl dairy cattle breed was created in the 18-19 centuries in Russia by breeding northern Great Russian cattle, which were short and poor productive, but well adapted to local climatic conditions and bad food base. It was shown by whole genome genotyping and sequencing that the Yaroslavl breed has unique genetics compared to Russian and other cattle breeds. The aim of the study was to assess the frequency of alleles and genotypes of three SNPs in the LPIN1 gene and to study the association of these SNPs with milk production traits in Yaroslavl cows. Blood samples from 142 cows of the Yaroslavl breed were obtained from two farms in the Yaroslavl region. Genotyping of SNPs was carried out by polymerase chain reaction-restriction fragment length polymorphism method. Associations of SNPs with 305-day milk yield, fat yield, fat percentages, protein yield, and protein percentages were studied from the first to the fourth lactation. Statistical tests were carried out using a mixed linear model, taking into account the relationship between individuals. We identified three SNPs - rs110871255, rs207681322 and rs109039955 with a frequency of a rare allele of 0.042-0.261 in Yaroslavl cows. SNP rs110871255 was associated with fat yield during the third and fourth lactations. SNP rs207681322 was associated with milk yield for the second, third and fourth lactations, as well as protein yield for the third lactation. Thus, we identified significant associations of SNPs rs207681322 and rs110871255 in the LPIN1 gene with a number of milk production traits during several lactations in Yaroslavl cows.
PubMed: 38465251
DOI: 10.18699/vjgb-24-14 -
BioRxiv : the Preprint Server For... Feb 2024Traumatic brain injury (TBI) can induce traumatic axonal injury in the optic nerve, which is referred to as traumatic optic neuropathy (TON). TON occurs in up to 5% of...
Traumatic brain injury (TBI) can induce traumatic axonal injury in the optic nerve, which is referred to as traumatic optic neuropathy (TON). TON occurs in up to 5% of TBI cases and leads to irreversible visual deficits. TON-induced phosphorylation of eIF2α, a downstream ER stress activator in the PERK pathway presents a potential point for therapeutic intervention. For eIF2α phosphorylation can lead to apoptosis or adaptation to stress. We hypothesized that dephosphorylation, rather than phosphorylation, of eIF2α would lead to reduced apoptosis and improved visual performance and retinal cell survival. Adult male mice were injected with Salubrinal (increases p-eIF2α) or ISRIB (decreases p-eIF2α) 60 minutes post-injury. Contrary to literature, both drugs hindered control animal visual function with minimal improvements in injured mice. Additionally, differences in eIF2α phosphorylation, antioxidant responses, and protein folding chaperones were different when examining protein expression between the retina and its axons in the optic nerve. These results reveal important compartmentalized ER stress responses to axon injury and suggest that interventions in the PERK pathway may alter necessary homeostatic regulation of the UPR in the retina.
PubMed: 38464302
DOI: 10.1101/2024.02.15.580435 -
BioRxiv : the Preprint Server For... Feb 2024The directed movement of eukaryotic cells is crucial for processes such as embryogenesis and immune cell trafficking. The enzyme Phosphatase and tensin homolog (PTEN)...
The directed movement of eukaryotic cells is crucial for processes such as embryogenesis and immune cell trafficking. The enzyme Phosphatase and tensin homolog (PTEN) dephosphorylates phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P ] to phosphatidylinositol 4,5-bisphosphate [PI(4,5)P ]. cells require both PTEN and the PTEN-like phosphatase CnrN to locally inhibit Ras activation to induce biased movement of cells away from the secreted chemorepellent protein AprA. Both PTEN and CnrN decrease basal levels of PI(3,4,5)P and increase basal numbers of macropinosomes, and AprA prevents this increase. AprA requires both PTEN and CnrN to increase PI(4,5)P levels, decrease PI(3,4,5)P levels, inhibit proliferation, decrease myosin II phosphorylation, and increase filopod sizes. AprA causes PTEN, similar to CnrN, to localize to the side of the cell towards AprA in an AprA gradient. However, PTEN and CnrN also have distinct roles in some signaling pathways. PTEN, but not CnrN, decreases basal levels of PI(4,5)P , AprA requires PTEN, but not CnrN, to induce cell roundness, and CnrN and PTEN have different effects on the number of filopods and pseudopods, and the sizes of filopods. Together, our results suggest that CnrN and PTEN play unique roles in signaling pathways, and possibly dephosphorylate PI(3,4,5)P in different membrane domains, to mediate chemorepulsion away from AprA.
PubMed: 38464111
DOI: 10.1101/2024.02.23.581751 -
Communications Biology Mar 2024Diabetic foot ulcer (DFU), a serious complication of diabetes, remains a clinical challenge. MicroRNAs affect inflammation and may have therapeutic value in DFU. Here,...
Diabetic foot ulcer (DFU), a serious complication of diabetes, remains a clinical challenge. MicroRNAs affect inflammation and may have therapeutic value in DFU. Here, we find that an miR-221-3p mimic reduces the inflammatory response and increases skin wound healing rates in a mouse model of diabetes, whereas miR-221-3p knockout produced the opposite result. In human keratinocytes cells, miR-221-3p suppresses the inflammatory response induced by high glucose. The gene encoding DYRK1A is a target of miR-221-3p. High glucose increases the expression of DYRK1A, but silencing DYRK1A expression decreases high glucose-induced inflammatory cytokine release via dephosphorylation of STAT3, a substrate of DYRK1A. Application of miR-221-3p mimic to human keratinocytes cells not only decreases DYRK1A expression but also inhibits high glucose-induced production of inflammatory cytokines to promote wound healing. This molecular mechanism whereby miR-221-3p regulates inflammation through the DYRK1A/STAT3 signaling pathway suggests targets and therapeutic approaches for treating DFU.
Topics: Animals; Humans; Mice; Cytokines; Diabetes Mellitus; Diabetic Foot; Glucose; Inflammation; Keratinocytes; MicroRNAs; Signal Transduction; STAT3 Transcription Factor; Wound Healing; Dyrk Kinases
PubMed: 38461326
DOI: 10.1038/s42003-024-05986-0 -
Advanced Science (Weinheim,... May 2024Targeting cancer-specific metabolic processes is a promising therapeutic strategy. Here, this work uses a compound library that directly inhibits metabolic enzymes to...
Targeting cancer-specific metabolic processes is a promising therapeutic strategy. Here, this work uses a compound library that directly inhibits metabolic enzymes to screen the potential metabolic targets in lung adenocarcinoma (LUAD). SHIN1, the specific inhibitor of serine hydroxymethyltransferase 1/2 (SHMT1/2), has a highly specific inhibitory effect on LUAD cells, and this effect depends mainly on the overexpression of SHMT2. This work clarifies that mitogen-activated protein kinase 1 (MAPK1)-mediated phosphorylation at Ser90 is the key mechanism underlying SHMT2 upregulation in LUAD and that this phosphorylation stabilizes SHMT2 by reducing STIP1 homology and U-box containing protein 1 (STUB1)-mediated ubiquitination and degradation. SHMT2-Ser90 dephosphorylation decreases S-adenosylmethionine levels in LUAD cells, resulting in reduced N-methyladenosine (mA) levels in global RNAs without affecting total protein or DNA methylation. Methylated RNA immunoprecipitation sequencing (MeRIP-Seq) and RNA sequencing (RNA-Seq) analyses further demonstrate that SHMT2-Ser90 dephosphorylation accelerates the RNA degradation of oncogenic genes by reducing mA modification, leading to the inhibition of tumorigenesis. Overall, this study elucidates a new regulatory mechanism of SHMT2 during oncogenesis and provides a theoretical basis for targeting SHMT2 as a therapeutic target in LUAD.
Topics: Animals; Humans; Mice; Adenocarcinoma of Lung; Adenosine; Carcinogenesis; Cell Line, Tumor; Disease Models, Animal; Glycine Hydroxymethyltransferase; Lung Neoplasms; Phosphorylation
PubMed: 38460155
DOI: 10.1002/advs.202307834