1.Poly(rC) binding protein 2 acts as a negative regulator of IRES-mediated translation of Hr mRNA
Jeong Ki KIM ; Injung KIM ; Keonwoo CHOI ; Jee Hyun CHOI ; Eunmin KIM ; Hwa Young LEE ; Jongkeun PARK ; Sungjoo KIM YOON
Experimental & Molecular Medicine 2018;50(2):e441-
During the hair follicle (HF) cycle, HR protein expression is not concordant with the presence of the Hr mRNA transcript, suggesting an elaborate regulation of Hr gene expression. Here we present evidence that the 5′ untranslated region (UTR) of the Hr gene has internal ribosome entry site (IRES) activity and this activity is regulated by the binding of poly (rC) binding protein 2 (PCBP2) to Hr mRNA. Overexpression and knockdown of PCBP2 resulted in a decrease in Hr 5′ UTR IRES activity and an increase in HR protein expression without changing mRNA levels. We also found that this regulation was disrupted in a mutant Hr 5′ UTR that has a mutation responsible for Marie Unna hereditary hypotrichosis (MUHH) in both mice and humans. These findings suggest that Hr mRNA expression is regulated at the post-transcriptional level via IRES-mediated translation control through interaction with PCPB2, but not in MUHH.
2.Niclosamide Inhibits Aortic Valve Interstitial Cell Calcification by Interfering with the GSK-3β/β-Catenin Signaling Pathway
Radhika ADHIKARI ; Saugat SHIWAKOTI ; Eunmin KIM ; Ik Jun CHOI ; Sin-Hee PARK ; Ju-Young KO ; Kiyuk CHANG ; Min-Ho OAK
Biomolecules & Therapeutics 2023;31(5):515-525
The most common heart valve disorder is calcific aortic valve stenosis (CAVS), which is characterized by a narrowing of the aortic valve. Treatment with the drug molecule, in addition to surgical and transcatheter valve replacement, is the primary focus of researchers in this field. The purpose of this study is to determine whether niclosamide can reduce calcification in aortic valve interstitial cells (VICs). To induce calcification, cells were treated with a pro-calcifying medium (PCM). Different concentrations of niclosamide were added to the PCM-treated cells, and the level of calcification, mRNA, and protein expression of calcification markers was measured. Niclosamide inhibited aortic valve calcification as observed from reduced alizarin red s staining in niclosamide treated VICs and also decreased the mRNA and protein expressions of calcification-specific markers: runt-related transcription factor 2 and osteopontin. Niclosamide also reduced the formation of reactive oxygen species, NADPH oxidase activity and the expression of Nox2 and p22 phox . Furthermore, in calcified VICs, niclosamide inhibited the expression of β-catenin and phosphorylated glycogen synthase kinase (GSK-3β), as well as the phosphorylation of AKT and ERK. Taken together, our findings suggest that niclosamide may alleviate PCM-induced calcification, at least in part, by targeting oxidative stress mediated GSK-3β/β-catenin signaling pathway via inhibiting activation of AKT and ERK, and may be a potential treatment for CAVS.
3.Tissue-specific expression and subcellular localization of ALADIN, the absence of which causes human triple A syndrome.
A Ri CHO ; Keum Jin YANG ; Yoonsun BAE ; Young Yil BAHK ; Eunmin KIM ; Hyungnam LEE ; Jeong Ki KIM ; Wonsang PARK ; Hyanshuk RHIM ; Soo Young CHOI ; Tsuneo IMANAKA ; Sungdae MOON ; Jongbok YOON ; Sungjoo Kim YOON
Experimental & Molecular Medicine 2009;41(6):381-386
Triple A syndrome is a rare genetic disorder caused by mutations in the achalasia-addisonianism-alacrima syndrome (AAAS) gene which encodes a tryptophan aspartic acid (WD) repeat-containing protein named alacrima-achalasia-adrenal insufficiency neurologic disorder (ALADIN). Northern blot analysis shows that the 2.1 kb AAAS mRNA is expressed in various tissues with stronger expression in testis and pancreas. We show that human ALADIN is a protein with an apparent molecular weight of 60 kDa, and expressed in the adrenal gland, pituitary gland and pancreas. Furthermore, biochemical analysis using anti-ALADIN antibody supports the previous finding of the localization of ALADIN in the nuclear membrane. The mutations S544G and S544X show that alteration of S544 residue affects correct targeting of ALADIN to the nuclear membrane.
Adrenal Insufficiency/*genetics
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Antibodies/immunology
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Cloning, Molecular
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DNA, Complementary/genetics
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Esophageal Achalasia/*genetics
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Gene Expression Profiling
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Hela Cells
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Humans
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Lacrimal Apparatus Diseases/*genetics
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Mutagenesis, Site-Directed
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Nerve Tissue Proteins/*analysis/*genetics/immunology
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Nuclear Pore/chemistry
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Nuclear Pore Complex Proteins/*analysis/*genetics/immunology
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RNA, Messenger/analysis/genetics
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Syndrome
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Tissue Distribution