Publications by authors named "Boon-Tin Chua"

Membrane contact between intracellular organelles is important in mediating organelle communication. However, the assembly of molecular machinery at membrane contact site and its internal organization correlating with its functional activity remain unclear. Here, we demonstrate that a gel-like condensation of Cidec, a crucial protein for obesity development by facilitating lipid droplet (LD) fusion, occurs at the LD-LD contact site (LDCS) through phase separation.

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Dysregulation of lipid homeostasis leads to the development of metabolic disorders including obesity, diabetes, cardiovascular disease and cancer. Lipid droplets (LDs) are subcellular organelles vital in the maintenance of lipid homeostasis by coordinating lipid synthesis, lipid storage, lipid secretion and lipolysis. Under fed condition, free fatty acids (FFAs) are remodeled and esterified into neutral lipids by lipogenesis and stored in the LDs.

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Insulin-stimulated hepatic glycogen synthesis is central to glucose homeostasis. Here, we show that PPP1R3G, a regulatory subunit of protein phosphatase 1 (PP1), is directly phosphorylated by AKT. PPP1R3G phosphorylation fluctuates with fasting-refeeding cycle and is required for insulin-stimulated dephosphorylation, i.

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Lipid droplets (LDs) are central organelles in maintaining lipid homeostasis. Defective LD growth often results in the development of metabolic disorders. LD fusion and growth mediated by cell death-inducing DNA fragmentation factor alpha (DFFA)-like effector (CIDE) family proteins are crucial for various biological processes including unilocular LD formation in the adipocytes, lipid storage in the liver, milk lipid secretion in the mammary epithelia cells, and lipid secretion in the skin sebocytes.

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Double FYVE-containing protein 1 (DFCP1) is ubiquitously expressed, participates in intracellular membrane trafficking and labels omegasomes through specific interactions with phosphatidylinositol-3-phosphate (PI3P). Previous studies showed that subcellular DFCP1 proteins display multi-organelle localization, including in the endoplasmic reticulum (ER), Golgi apparatus and mitochondria. However, its localization and function on lipid droplets (LDs) remain unclear.

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Lipid droplets (LDs) are important organelles involved in energy storage and expenditure. LD dynamics has been investigated using genome-wide image screening methods in yeast and other model organisms. For most studies, genes were identified using two-dimensional images with LD enlargement as readout.

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Lipid droplets (LDs) are intracellular organelles and a central site for lipid synthesis, storage, and mobilization. The size of LDs reflects the dynamic regulation of lipid metabolism in cells. Previously, we found that cell death-inducing DFFA-like effector C (CIDEC) mediates LD fusion and growth by lipid transfer through LD-LD contact sites in adipocytes and hepatocytes.

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PLEKHA7, a gene recently associated with primary angle closure glaucoma (PACG), encodes an apical junctional protein expressed in components of the blood aqueous barrier (BAB). We found that PLEKHA7 is down-regulated in lens epithelial cells and in iris tissue of PACG patients. PLEKHA7 expression also correlated with the C risk allele of the sentinel SNP rs11024102 with the risk allele carrier groups having significantly reduced PLEKHA7 levels compared to non-risk allele carriers.

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Targeting EGFR is a validated approach in the treatment of squamous-cell cancers (SCCs), although there are no established biomarkers for predicting response. We have identified a synonymous mutation in EGFR, c.2361G>A (encoding p.

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While various tyrosine kinases have been associated with the pathogenesis of hepatocellular carcinoma (HCC), the identification of a dominant therapeutic target among them remains a challenge. Here, we investigated the role of Tyro3, a relatively uncharacterized member of the TAM (Tyro3, Axl and Mer) receptor family. The present study aimed to profile and identify potential association between Tyro3 expression in HCC and cancer phenotypes.

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Effective pharmacological intervention of advanced hepatocellular carcinoma (HCC) is currently lacking. Despite the use of tyrosine kinase inhibitors (TKIs) for the targeted therapy of several malignancies, no agent has been developed to specifically interfere with the oncogenic tyrosine kinase signaling aberrations found in HCC. Therefore, we adopted an orthogonal biological phenotypic screening approach to uncover candidate compounds: based on a potent cytotoxicity toward HCC-derived cell lines, and minimal toxicity toward normal liver cells.

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The advent of effective targeted therapeutics has led to increasing emphasis on precise biomarkers for accurate patient stratification. Here, we describe the role of ACK1, a non-receptor tyrosine kinase in abrogating migration and invasion in KRAS mutant lung adenocarcinoma. Bosutinib, which inhibits ACK1 at 2.

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Aberrations in fibroblast growth factor receptor (FGFR) signaling are instrumental to the pathophysiology of several malignancies and disorders. Hence, FGFR inhibitors are explored in therapeutics with early candidates developed as competitors for the ATP-binding pocket in the kinase domain. More recent programs yielded compounds of diverse scaffolds with alternative binding modes.

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Background: We had previously demonstrated overexpression of fibroblast growth factor receptor-4 (FGFR4) in hepatocellular carcinoma (HCC). However, additional molecular mechanisms resulting in amplified FGFR4 signaling in HCC remain under-studied. Here, we studied the mechanistic role of its co-receptor klotho-beta (KLB) in driving elevated FGFR4 activity in HCC progression.

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Activated Cdc42-associated Kinase, ACK1, is a non-receptor tyrosine kinase with numerous interacting partners, including Cdc42 and EGFR. Gene amplification and overexpression of ACK1 were found in many cancer types such as those of the lung and prostate. Previously, we identified both somatic- and germ line missense mutations in the ACK1 coding sequence, by surveying 261 cancer cell lines and 15 control tissues.

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Background: The serine/threonine kinase PKB/Akt plays essential role in various cellular processes including cell growth and proliferation, metabolism and cell survival. The importance of the Akt pathway is highlighted by the mutation of various components of the pathway such as the PTEN and PI3-kinase (P110alpha) in human cancers. In this paper, we employed an RNA interference library targeting all human kinases to screen for kinases involved in the regulation of Akt activation, in particular serine 473 phosphorylation.

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The pathogenesis of various acute and chronic neurodegenerative disorders has been linked to excitotoxic processes and excess generation of nitric oxide. We investigated the deleterious effects of calpain activation in nitric oxide-elicited neuronal apoptosis. In this model, nitric oxide triggers apoptosis of murine cerebellar granule cells by an excitotoxic mechanism requiring glutamate exocytosis and receptor-mediated intracellular calcium overload.

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Increasing evidence suggests that movement of key proteins in or out of mitochondria during apoptosis is essential for the regulation of apoptosis. Here, we report identification of the actin-binding protein cofilin by a proteomic approach, as such a factor translocated from cytosol into mitochondria after induction of apoptosis. We found that after induction of apoptosis, cofilin was translocated to mitochondria before release of cytochrome c.

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