Journal: PNAS Nexus

Article Title: Unraveling the complex dynamics of signaling molecules in cellular signal transduction

doi: 10.1093/pnasnexus/pgae020

Figure Lengend Snippet: V-shape changes in CDK1 mediated by polysulfides and similar p62. a) Protein–protein interaction network of 29 antioxidant genes regulated by ROS increase in cells 3, 7, and 10 is obtained from PCR array analysis of 80 antioxidant-related genes. Genes were imported into STRING for interaction analysis and visualized using Cytoscape. Three-bar indicators show gene expression levels in cells 3, 7, and 10; V-shape changed genes are highlighted. b) Western blot analysis shows CDK1 expression in redox-modified A549 cells 1–10 displays a V-shape trend. (c) Inhibiting Nrf2 with ML385 eliminates CDK1 activity. d) Inhibiting polysulfide with PAG eliminates CDK1 activation. e) Inhibiting GSH synthesis with BSO has no effect and even slightly enhances CDK1. CDK1 level is suppressed by external polysulfide precursor Na 2 S 4 (f) and p62 inhibitor XRK3F2 (g) in a dose-dependent manner. h) Schematic model showing the dynamic regulation of cellular CDK1 through the Nrf2/polysulfide/p62 pathway. All experimental values were from three independent experiments. Error bars represent one SD.

Article Snippet: CSE (30068) antibody was purchased from Cell Signaling Technology (Boston, MA, USA). β-Actin (AM1021b) and GAPDH (AM1020b), and Cdc2 (CDK1) (AP1497b) antibodies were purchased from Abgent (San Diego, CA, USA).

Techniques: Expressing, Western Blot, Modification, Activity Assay, Activation Assay

Journal: PNAS Nexus

Article Title: Unraveling the complex dynamics of signaling molecules in cellular signal transduction

doi: 10.1093/pnasnexus/pgae020

Figure Lengend Snippet: Dynamic induction of cell cycle arrest by low-level ROS facilitates cell survival. a) Cell cycle arrest at the G2/M phase in redox-modified A549 cells 1–10 displays a reversed V-shape, as determined using propidium iodide staining. Inhibiting Nrf2 activity with ML385 (b) or polysulfide synthesis with PAG (c) eliminates time-dependent cell cycle arrest, while inhibiting GSH with BSO (d) does not. e) Polysulfide precursor Na 2 S 4 enhances cell cycle arrest in a dose-dependent manner. f–h) EC 50 value of cells treated with GNP 7 (471 μg/mL) does not change significantly in the presence of BSO (412 μg/mL) but decreases significantly in the presence of PAG (121 μg/mL). i–k) EC 50 values of cells treated with GNPs 1–10 without inhibitor (i) with BSO (j) or PAG (k) show cell death is inevitable when polysulfide is inhibited, and Nrf2-regulated polysulfide promotes cell survival. All experimental values were from three independent experiments. Error bars in (f–h) represent two SDs. All other error bars represent one SD. l) ROS-triggered dynamic signal transduction pathways induce cell survival. As cellular ROS accumulates, a gradual increase in Nrf2 triggers dynamic V-shape changes in GSH and reversed V-shape changes in polysulfides. Polysulfides suppress both p62 and CDK1 in a time-dependent V-shape pattern. These dynamic changes facilitate cell survival by arresting the cell cycle at the G2/M phase in a time-dependent reversed V-shape pattern.

Article Snippet: CSE (30068) antibody was purchased from Cell Signaling Technology (Boston, MA, USA). β-Actin (AM1021b) and GAPDH (AM1020b), and Cdc2 (CDK1) (AP1497b) antibodies were purchased from Abgent (San Diego, CA, USA).

Techniques: Modification, Staining, Activity Assay, Transduction