Hong-Duk Youn

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O-linked-N-acetylglucosamine (O-GlcNAc) has emerged as a critical regulator of diverse cellular processes, but its role in embryonic stem cells (ESCs) and pluripotency has not been investigated. Here we show that O-GlcNAcylation directly regulates core components of the pluripotency network. Blocking O-GlcNAcylation disrupts ESC self-renewal and(More)
von Hippel-Lindau (VHL) disease is a rare autosomal dominant cancer syndrome. Although hypoxia-inducible factor-alpha (HIFalpha) is a well-documented substrate of von Hippel-Lindau tumor suppressor protein (pVHL), it remains unclear whether the dysregulation of HIF is sufficient to account for de novo tumorigenesis in VHL-deleted cells. Here we found that(More)
This study examined the role of calcineurin, a major calcium-dependent protein phosphatase, in dephosphorylating Ser-9 and activating glycogen synthase kinase-3beta (GSK-3beta). Treatment with calcineurin inhibitors increased phosphorylation of GSK-3beta at Ser-9 in SH-SY5Y human neuroblastoma cells. The over-expression of a constitutively active(More)
Menin, a gene product of multiple endocrine neoplasia type I (MEN1), is known to act as a tumor suppressor to repress JunD transcription factor. However, the mechanism by which Menin represses JunD transcriptional activity was still unclear. In this study, we found that Menin is a corepressor against JunD transcriptional activity via recruitment of histone(More)
In mammals, the canonical histone H3 and the variant H3.3 are assembled into chromatin through replication-coupled and replication-independent (RI) histone deposition pathways, respectively, to play distinct roles in chromatin function. H3.3 is largely associated with transcriptionally active regions via the activity of RI histone chaperone, HIRA. However,(More)
The myocyte enhancer factor-2 (MEF2) family of transcription factors has important roles in the development and function of T cells, neuronal cells and muscle cells. MEF2 is capable of repressing or activating transcription by association with a variety of co-repressors or co-activators in a calcium-dependent manner. Transcriptional repression by MEF2 has(More)
Pluripotent stem cells (PSCs) have distinct metabolic properties that support their metabolic and energetic needs and affect their stemness. In particular, high glycolysis is critical for the generation and maintenance of PSCs. However, it is unknown how PSCs maintain and acquire this metabolic signature. In this study, we found that core pluripotency(More)
Cancer cells rely mainly on glycolysis rather than mitochondrial respiration for energy production, which is called the Warburg effect. p53 mutations are observed in about half of cancer cases, and p53 controls the cell cycle and cell death in response to cellular stressors. p53 has been emphasized as a metabolic regulator involved in glucose, glutamine,(More)
Despite the involvement in diverse physiological process and pleiotropic expression profile, the molecular functions of Nur77 are not likely to be fully elucidated. From the effort to find a novel function of Nur77, we detected molecular interaction between Nur77 and PKC. Details of interaction revealed that C-terminal ligand binding domain (LBD) of Nur77(More)
One of the temperature-sensitive alleles of CEG1, a guanylyltransferase subunit of the Saccharomyces cerevisiae capping enzyme, showed 6-azauracil (6AU) sensitivity at the permissive growth temperature, which is a phenotype that is correlated with a transcription elongation defect. This temperature-sensitive allele, ceg1-63, has an impaired ability to(More)