Medicine and Health Sciences Commons^™

Kras Inhibitor That Simultaneously Inhibits Nucleotide Exchange Activity And Effector Engagement, Cynthia V Pagba, Amit K Gupta, Ali K Naji, Dharini Van Der Hoeven, Kelly Churion, Xiaowen Liang, Jacob Jakubec, Magnus Hook, Yan Zuo, Marisela Martinez De Kraatz, Jeffrey A Frost, Alemayehu A Gorfe

Journal Articles

We describe a small molecule ligand ACA-14 (2-hydroxy-5-{[(2-phenylcyclopropyl) carbonyl] amino} benzoic acid) as an initial lead for the development of direct inhibitors of KRAS, a notoriously difficult anticancer drug target. We show that the compound binds to KRAS near the switch regions with affinities in the low micromolar range and exerts different effects on KRAS interactions with binding partners. Specifically, ACA-14 impedes the interaction of KRAS with its effector Raf and reduces both intrinsic and SOS-mediated nucleotide exchange rates. Likely as a result of these effects, ACA-14 inhibits signal transduction through the MAPK pathway in cells expressing mutant KRAS and …

Remodeling Of The Plasma Membrane By Surface-Bound Protein Monomers And Oligomers: The Critical Role Of Intrinsically Disordered Regions, Mussie K Araya, Yong Zhou, Alemayehu A Gorfe

Journal Articles

The plasma membrane (PM) of cells is a dynamic structure whose morphology and composition is in constant flux. PM morphologic changes are particularly relevant for the assembly and disassembly of signaling platforms involving surface-bound signaling proteins, as well as for many other mechanochemical processes that occur at the PM surface. Surface-bound membrane proteins (SBMP) require efficient association with the PM for their function, which is often achieved by the coordinated interactions of intrinsically disordered regions (IDRs) and globular domains with membrane lipids. This review focuses on the role of IDR-containing SBMPs in remodeling the composition and curvature of the PM. …

Bcl11b And Atoh8 Coordinate Cellular Plasticity For Reprogramming And Transformation, Mo-Fan Huang, Rachel Shoemaker, Dung-Fang Lee

Journal Articles

By dissecting and comparing the transcriptional trajectories and epigenomic traits of reprogramming and transforming cells at the single-cell resolution, Huyghe et al discovered Bcl11b and Atoh8, two key transcription factors controlling cell plasticity during pluripotent reprogramming and oncogenic transformation.

New Non-Fullerene Acceptor With Extended Conjugation Of Cyclopenta [2,1-B:3,4-B'] Dithiophene For Organic Solar Cells, Cheng Sun, Sanseong Lee, Changeun Choi, Soyeong Jeong, Juhui Oh, Ju-Hyeon Kim, Jaeyoung Kim, Ho Eon Baek, Hongkyu Kang, Soo-Young Jang, Hyun Ho Choi, Kwanghee Lee, Yun-Hi Kim

Journal Articles

Herein, we design and characterize 9-heterocyclic ring non-fullerene acceptors (NFAs) with the extended backbone of indacenodithiophene by cyclopenta [2,1-b:3,4-b'] dithiophene (CPDT). The planar conjugated CPDT donor enhances absorption by reducing vibronic transition and charge transport. Developed NFAs with different end groups shows maximum absorption at approximately 790-850 nm in film. Because of the electronegative nature of the end-group, the corresponding acceptors showed deeper LUMO energy levels and red-shifted ultraviolet absorption. We investigate the crystallinity, film morphology, surface energy, and electronic as well as photovoltaic performance. The organic photovoltaic cells using novel NFAs with the halogen end groups fluorine or chlorine …

Human Nop2/Nsun1 Regulates Ribosome Biogenesis Through Non-Catalytic Complex Formation With Box C/D Snornps, Han Liao, Anushri Gaur, Hunter Mcconie, Amirtha Shekar, Karen Wang, Jeffrey T Chang, Ghislain Breton, Catherine Denicourt

Journal Articles

5-Methylcytosine (m5C) is a base modification broadly found on various RNAs in the human transcriptome. In eukaryotes, m5C is catalyzed by enzymes of the NSUN family composed of seven human members (NSUN1-7). NOP2/NSUN1 has been primarily characterized in budding yeast as an essential ribosome biogenesis factor required for the deposition of m5C on the 25S ribosomal RNA (rRNA). Although human NOP2/NSUN1 has been known to be an oncogene overexpressed in several types of cancer, its functions and substrates remain poorly characterized. Here, we used a miCLIP-seq approach to identify human NOP2/NSUN1 RNA substrates. Our analysis revealed that NOP2/NSUN1 catalyzes the …

New Sedatives And Analgesic Drugs For Gastrointestinal Endoscopic Procedures, Jae Min Lee, Yehyun Park, Jin Myung Park, Hong Jun Park, Jun Yong Bae, Seung Young Seo, Jee Hyun Lee, Hyung Ku Chon, Jun-Won Chung, Hyun Ho Choi, Jun Kyu Lee, Byung-Wook Kim

Journal Articles

Procedural sedation has become increasingly common in endoscopy. Sedatives and analgesics induce anxiolysis and amnesia. In addition, an appropriate level of sedation is necessary for safe procedures including therapeutic endoscopy. Midazolam and propofol are the most commonly used drugs in sedative endoscopy. In recent years, the need to ascertain the safety and effectiveness of sedation has increased in practice. Therefore, new sedatives and analgesic drugs for optimal sedative endoscopy, have recently emerged. This article reviews the characteristics of sedatives and analgesics, and describes their clinical use in gastrointestinal endoscopy.

Short Signature Rpob Gene Sequence To Differentiate Species In Mycobacterium Abscessus Group, Jian R Bao, Kileen L Shier, Ronald N Master, Robert S Jones, Richard B Clark

Journal Articles

Mycobacterium abscessus group (MAG) are rapidly growing acid-fast bacteria that consist of three closely related species: M. abscessus (Ma), M. bolletii (Mb), and M. massiliense (Mm). Differentiation of these species can be difficult but is increasingly requested owing to recent infectious outbreaks and their differential drug resistance. We developed a novel and rapid pyrosequencing method using short signature sequences (35 to 45 bp) at a hypervariable site in the rpoB gene to differentiate the three MAG species, along with M. chelonae (Mc), and M. immunogenum (Mi). This method was evaluated …

A Differential Diagnosis Of Unusual Gastric Ulcer, Soo-Yoon Sung, Hyun Ho Choi, Kyung Jin Seo

Journal Articles

The endoscopic findings of diffuse large B cell lymphoma have various presentations. In our case, the patient had developed multiple elevated central ulceration lesions, and the peripheral elevated portion had a heaped-up margin. The margin had a sharp, smooth edge that was not infiltrative and could be confused with a simple gastric ulcer. Endoscopists should be aware of the possibility of multiple lymphoma ulcers with heaped-up margins. We present some unusual endoscopic features of lymphoma, which are easily misdiagnosed as gastric ulcers.

Generation Of A Homozygous Knock-In Human Embryonic Stem Cell Line Expressing Meos4b-Tagged Ctr1, Yi-Hung Chen, Pei-San Huang, Meng-Hsuan Wen, Manhua Pan, Dung-Fang Lee, Tai-Yen Chen

Journal Articles

Copper transporter 1 (CTR1) is the major membrane protein responsible for cellular copper (Cu) uptake and mediates cellular copper homeostasis. To elucidate CTR1's behavior using imaging approaches, we generated a homozygous knock-in human embryonic stem cell (hESC) clone expressing photoconvertible fluorescence protein mEos4b-tagged endogenous CTR1 using CRISPR-Cas9 mediated homologous recombination. The engineered cells express functional CTR1-mEos4b fusion and have normal stem cell morphology. They remain pluripotent and can be differentiated into all three germ layers in vitro. This resource allows the study of CTR1 at an endogenous level in different cellular contexts using microscopy.

Mettl14-Mediated Epitranscriptome Modification Of Mn1 Mrna Promote Tumorigenicity And All-Trans-Retinoic Acid Resistance In Osteosarcoma, Hong-Bo Li, Gang Huang, Jian Tu, Dong-Ming Lv, Qing-Lin Jin, Jun-Kai Chen, Yu-Tong Zou, Dung-Fang Lee, Jing-Nan Shen, Xian-Biao Xie

Journal Articles

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents. The molecular mechanism behind OS progression and metastasis remains poorly understood, which limits the effectiveness of current therapies. RNA N

METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS), dot blotting, and colorimetric ELISA were used to detect m

FINDINGS: We observed the abundance of m

INTERPRETATION: Our study revealed that METTL14 contributes to OS progression and ATRA resistance as an m

FUNDING: This work was supported by the National Natural Science Foundation of China (Grants 81972510 and 81772864).

Unexpected Movement Of The Esophagus Across The Aorta, Hyun Ho Choi, Soo-Yoon Sung, Yoon Ho Ko

Journal Articles

Tumor regression throughout treatment would induce organ movement, but little is known of this in the esophagus. To achieve successful tumor regression, radiation therapy requires several weeks of radiation to be delivered accurately to the tumor. Usually, a 5-10 mm margin is allowed for set-up error and internal organ motion. Our case exhibited an unexpectedly large movement of the esophagus across the aorta with tumor regression that extended outside the margin and thus outside the radiotherapy field. These movements may affect subsequent invasive procedures or treatment during cancer therapy. After the unexpected large movement of the esophagus due to tumor …

The Uprmt Preserves Mitochondrial Import To Extend Lifespan, Nan Xin, Jenni Durieux, Chunxia Yang, Suzanne Wolff, Hyun-Eui Kim, Andrew Dillin

Journal Articles

The mitochondrial unfolded protein response (UPRmt) is dedicated to promoting mitochondrial proteostasis and is linked to extreme longevity. The key regulator of this process is the transcription factor ATFS-1, which, upon UPRmt activation, is excluded from the mitochondria and enters the nucleus to regulate UPRmt genes. However, the repair proteins synthesized as a direct result of UPRmt activation must be transported into damaged mitochondria that had previously excluded ATFS-1 owing to reduced import efficiency. To address this conundrum, we analyzed the role of the import machinery when the UPRmt was induced. Using in vitro and in vivo analysis of mitochondrial …

Obscurin Regulates Ankyrin Macromolecular Complex Formation, Janani Subramaniam, Gokay Yamankurt, Shane R Cunha

Journal Articles

Obscurin is a large scaffolding protein in striated muscle that maintains sarcolemmal integrity and aligns the sarcoplasmic reticulum with the underlying contractile machinery. Ankyrins are a family of adaptor proteins with some isoforms that interact with obscurin. Previous studies have examined obscurin interacting with individual ankyrins. In this study, we demonstrate that two different ankyrins interact with obscurin's carboxyl terminus via independent ankyrin-binding domains (ABDs). Using in-vitro binding assays, co-precipitation assays, and FLIM-FRET analysis, we show that obscurin interacts with small ankyrin 1.5 (sAnk1.5) and the muscle-specific ankyrin-G isoform (AnkG107). While there is no direct interaction between sAnk1.5 and AnkG107, …

Phosphatidylserine And Phosphatidylethanolamine Asymmetry Have A Negligible Effect On The Global Structure, Dynamics, And Interactions Of The Kras Lipid Anchor, Mussie K Araya, Alemayehu A Gorfe

Journal Articles

The intrinsically disordered C-terminus of the prominent oncogenic protein KRAS-4B (KRAS) selectively interacts and clusters with phosphatidylserine (PS) lipids in the plasma membrane (PM). This 11-residue segment, called tK, contains a polybasic domain (PBD) of six contiguous lysine residues and a farnesylated cysteine. Previous molecular dynamics (MD) simulation studies of tK in phosphatidylcholine (PC)/PS bilayers have suggested that backbone conformational dynamics modulate tK-PS interactions. These simulations have been conducted in symmetric membranes whereas the PM is compositionally asymmetric, with the inner leaflet, where KRAS is localized, being enriched with PS and phosphatidylethanolamine (PE) lipids. To examine if bilayer asymmetry affects …