Human hexokinase 2 is an essential regulator of glycolysis that couples metabolic and proliferative activities in cancer cells. The binding of hexokinase 2 to the outer membrane of mitochondria is ...critical for its oncogenic activity. However, the regulation of hexokinase 2 binding to mitochondria remains unclear. Here, we report that SUMOylation regulates the binding of hexokinase 2 to mitochondria. We find that hexokinase 2 can be SUMOylated at K315 and K492. SUMO-specific protease SENP1 mediates the de-SUMOylation of hexokinase 2. SUMO-defective hexokinase 2 preferably binds to mitochondria and enhances both glucose consumption and lactate production and decreases mitochondrial respiration in parallel. This metabolic reprogramming supports prostate cancer cell proliferation and protects cells from chemotherapy-induced cell apoptosis. Moreover, we demonstrate an inverse relationship between SENP1-hexokinase 2 axis and chemotherapy response in prostate cancer samples. Our data provide evidence for a previously uncovered posttranslational modification of hexokinase 2 in cancer cells, suggesting a potentially actionable strategy for preventing chemotherapy resistance in prostate cancer.
Abstract
Metabolic programming and mitochondrial dynamics along with T cell differentiation affect T cell fate and memory development; however, how to control metabolic reprogramming and ...mitochondrial dynamics in T cell memory development is unclear. Here, we provide evidence that the SUMO protease SENP1 promotes T cell memory development via Sirt3 deSUMOylation. SENP1-Sirt3 signalling augments the deacetylase activity of Sirt3, promoting both OXPHOS and mitochondrial fusion. Mechanistically, SENP1 activates Sirt3 deacetylase activity in T cell mitochondria, leading to reduction of the acetylation of mitochondrial metalloprotease YME1L1. Consequently, deacetylation of YME1L1 suppresses its activity on OPA1 cleavage to facilitate mitochondrial fusion, which results in T cell survival and promotes T cell memory development. We also show that the glycolytic intermediate fructose-1,6-bisphosphate (FBP) as a negative regulator suppresses AMPK-mediated activation of the SENP1-Sirt3 axis and reduces memory development. Moreover, glucose limitation reduces FBP production and activates AMPK during T cell memory development. These data show that glucose limitation activates AMPK and the subsequent SENP1-Sirt3 signalling for T cell memory development.
Mitochondrial stress is considered as a factor that reprograms the mitochondrial biogenesis and metabolism. As known, SUMOylation occurs through a series of stress-induced biochemical reactions. ...During the process of SUMOylation, the small ubiquitin-like modifier (SUMO) and its specific proteases (SENPs) are key signal molecules. Furthermore, they are considered as novel mitochondrial stress sensors that respond to the signals produced by various stresses. The responses are critical for mitochondrial homeostasis. The scope of this review is to provide an overview of the function of SUMOylation in the mitochondrial stress response, to delineate a SUMOylation-involved signal network diagram, and to highlight a number of key questions that remain answered.
Posttranslational modifications of nuclear proteins, including transcription factors, nuclear receptors, and their coregulators, have attracted much attention in cancer research. Although ...phosphorylation of oligodendrocyte transcription factor 2 (Olig2) may contribute to the notorious resistance of gliomas to radiation and genotoxic drugs, the precise mechanisms remain elusive. We show here that in addition to phosphorylation, Olig2 is also conjugated by small ubiquitin-like modifier-1 (SUMO1) at three lysine residues K27, K76, and K112. SUMOylation is required for Olig2 to suppress p53-mediated cell cycle arrest and apoptosis induced by genotoxic damage, and to enhance resistance to temozolomide (TMZ) in glioma. Both SUMOylation and triple serine motif (TSM) phosphorylation of Olig2 are required for the antiapoptotic function. Olig2 SUMOylation enhances its genetic targeting ability, which in turn occludes p53 recruitment to Cdkn1a promoter for DNA-damage responses. Our work uncovers a SUMOylation-dependent regulatory mechanism of Olig2 in regulating cancer survival.
Spindle position control is essential for cell fate determination and organogenesis. Early studies indicate the essential role of the evolutionarily conserved Gαi/LGN/NuMA network in spindle ...positioning. However, the regulatory mechanisms that couple astral microtubules dynamics to the spindle orientation remain elusive. Here we delineated a new mitosis-specific crotonylation-regulated astral microtubule-EB1-NuMA interaction in mitosis. EB1 is a substrate of TIP60, and TIP60-dependent crotonylation of EB1 tunes accurate spindle positioning in mitosis. Mechanistically, TIP60 crotonylation of EB1 at Lys66 forms a dynamic link between accurate attachment of astral microtubules to the lateral cell cortex defined by NuMA-LGN and fine tune of spindle positioning. Real-time imaging of chromosome movements in HeLa cells expressing genetically encoded crotonylated EB1 revealed the importance of crotonylation dynamics for accurate control of spindle orientation during metaphase-anaphase transition. These findings delineate a general signaling cascade that integrates protein crotonylation with accurate spindle positioning for chromosome stability in mitosis.
To get rid of the dependence on an external current during the electrochemical etching of aluminum foil, we explored a self-etching tunnel method. Specimens were prepared by electrodepositing trace ...amounts of Cu onto the surface of aluminum foil, and self-etching occurred in the electrolyte without current input. The effect of electrodeposited Cu on the self-etching of tunnels on the aluminum foil was examined, and the mechanism was investigated by the open circuit potential, SEM, polarization curve, EIS, weight loss, thickness reduction, pit density, and tunnel size. The results of the analysis showed that Al–Cu microbatteries with Al as the anode and Cu as the cathode were formed by the uniform electrodeposition of trace Cu on the aluminum foil surface. The current of Al–Cu microbatteries enhanced the etching drive of aluminum foil, resulting in an accelerated tunnel self-etching. When the electrodeposition time was 10 s, samples showed better etching performance, and the pitting density and weight loss were 49.76% and 21.29%, respectively. The logarithmic free corrosion current density log(
i
corr
) of the aluminum foil increased from − 1.532 A cm
−2
to − 1.432 A cm
−2
, the free corrosion potential
E
corr
decreased from − 0.711 V to − 0.807 V, and the reaction resistance
R
decreased from 14.15 Ω cm
−2
to 8.399 Ω cm
−2
. The tunnels were self-etched spontaneously without an applied current and were easy to generate.
Lung adenocarcinoma (LUAD) is the most common lung cancer, which accounts for about 35–40% of all lung cancer patients. Despite therapeutic advancements in recent years, the overall survival time of ...LUAD patients still remains poor, especially KRAS mutant LUAD. Therefore, it is necessary to further explore novel targets and drugs to improve the prognos is for LUAD. Ferroptosis, an iron-dependent regulated cell death (RCD) caused by lipid peroxidation, has attracted much attention recently as an alternative target for apoptosis in LUAD therapy. Ferroptosis has been found to be closely related to LUAD at every stage, including initiation, proliferation, and progression. In this review, we will provide a comprehensive overview of ferroptosis mechanisms, its regulation in LUAD, and the application of targeting ferroptosis for LUAD therapy.
Progression of mitotic cell cycle and chromosome condensation and segregation are controlled by posttranslational protein modifications such as phosphorylation and SUMOylation. However, how SUMO ...isopeptidases (SENP) regulate cell mitotic procession is largely unknown. Here, we demonstrate that precise phosphorylation of SENP3 during mitosis suppresses SENP3 deSUMOylation activity towards chromosome-associated proteins, including topoisomerase IIα (TopoIIα). Cyclin B-dependent kinases 1 and protein phosphatase 1α were identified as the kinase and phosphatase in control of mitotic SENP3 phosphorylation, respectively. SENP3 phosphorylation decreased its interaction with TopoIIα, resulting in reduced SENP3 deSUMOylation activity on TopoIIα. Furthermore, we observed mitotic arrest, increased chromosome instability, and promotion of tumorigenesis in cells expressing a nonphosphorylatable SENP3 mutant. These data show that SENP3 phosphorylation plays a crucial role in regulating the SUMOylation of chromosome-associated proteins and chromosome stability in mitosis.
Phosphorylation of SENP3 regulates SUMOylation of chromosome-associated proteins to maintain genomic stability during mitosis.
.
Regulatory T (Treg) cells are essential for maintaining immune homeostasis and tolerance, but the mechanisms regulating the stability and function of Treg cells have not been fully elucidated. Here ...we show SUMO-specific protease 3 (SENP3) is a pivotal regulator of Treg cells that functions by controlling the SUMOylation and nuclear localization of BACH2. Treg cell-specific deletion of Senp3 results in T cell activation, autoimmune symptoms and enhanced antitumor T cell responses. SENP3-mediated BACH2 deSUMOylation prevents the nuclear export of BACH2, thereby repressing the genes associated with CD4
T effector cell differentiation and stabilizing Treg cell-specific gene signatures. Notably, SENP3 accumulation triggered by reactive oxygen species (ROS) is involved in Treg cell-mediated tumor immunosuppression. Our results not only establish the role of SENP3 in the maintenance of Treg cell stability and function via BACH2 deSUMOylation but also clarify the function of SENP3 in the regulation of ROS-induced immune tolerance.
Although oncogenicity of the stem cell regulator SOX9 has been implicated in many solid tumors, its role in lymphomagenesis remains largely unknown. In this study, SOX9 was overexpressed ...preferentially in a subset of diffuse large B-cell lymphomas (DLBCLs) that harbor IGH-BCL2 translocations. SOX9 positivity in DLBCL correlated with an advanced stage of disease. Silencing of SOX9 decreased cell proliferation, induced G1/S arrest, and increased apoptosis of DLBCL cells, both in vitro and in vivo. Whole-transcriptome analysis and chromatin immunoprecipitation–sequencing assays identified DHCR24, a terminal enzyme in cholesterol biosynthesis, as a direct target of SOX9, which promotes cholesterol synthesis by increasing DHCR24 expression. Enforced expression of DHCR24 was capable of rescuing the phenotypes associated with SOX9 knockdown in DLBCL cells. In models of DLBCL cell line xenografts, SOX9 knockdown resulted in a lower DHCR24 level, reduced cholesterol content, and decreased tumor load. Pharmacological inhibition of cholesterol synthesis also inhibited DLBCL xenograft tumorigenesis, the reduction of which is more pronounced in DLBCL cell lines with higher SOX9 expression, suggesting that it may be addicted to cholesterol. In summary, our study demonstrated that SOX9 can drive lymphomagenesis through DHCR24 and the cholesterol biosynthesis pathway. This SOX9-DHCR24-cholesterol biosynthesis axis may serve as a novel treatment target for DLBCLs.
•SOX9 plays an oncogenic role in germinal center B-cell type, IGH-BCL2+ DLBCL, by promoting cell proliferation and inhibiting apoptosis.•SOX9 drives lymphomagenesis through upregulation of DHCR24, the key final enzyme in the cholesterol biosynthesis pathway.
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