Cell and Developmental Biology Commons^™

Serine-Dependent Sphingolipid Synthesis Is A Metabolic Liability Of Aneuploid Cells, Sunyoung Hwang, H. Tobias Gustafsson, Ciara O’Sullivan, Gianna Bisceglia, Xinhe Huang, Christian Klose, Andrej Schevchenko, Robert C. Dickson, Paola Cavaliere, Noah Dephoure, Eduardo M. Torres

Molecular and Cellular Biochemistry Faculty Publications

Aneuploidy disrupts cellular homeostasis. However, the molecular mechanisms underlying the physiological responses and adaptation to aneuploidy are not well understood. Deciphering these mechanisms is important because aneuploidy is associated with diseases, including intellectual disability and cancer. Although tumors and mammalian aneuploid cells, including several cancer cell lines, show altered levels of sphingolipids, the role of sphingolipids in aneuploidy remains unknown. Here, we show that ceramides and long-chain bases, sphingolipid molecules that slow proliferation and promote survival, are increased by aneuploidy. Sphingolipid levels are tightly linked to serine synthesis, and inhibiting either serine or sphingolipid synthesis can specifically impair the fitness …

Transcriptome-Wide Identification Of The Rna-Binding Landscape Of The Chromatin-Associated Protein Parp1 Reveals Functions In Rna Biogenesis, Manana Melikishvili, Julia H. Chariker, Eric C. Rouchka, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Recent studies implicate Poly (ADP-ribose) polymerase 1 (PARP1) in alternative splicing regulation, and PARP1 may be an RNA-binding protein. However, detailed knowledge of RNA targets and the RNA-binding region for PARP1 are unknown. Here we report the first global study of PARP1–RNA interactions using PAR–CLIP in HeLa cells. We identified a largely overlapping set of 22 142 PARP1–RNA-binding peaks mapping to mRNAs, with 20 484 sites located in intronic regions. PARP1 preferentially bound RNA containing GC-rich sequences. Using a Bayesian model, we determined positional effects of PARP1 on regulated exon-skipping events: PARP1 binding upstream and downstream of the skipped exons …

Deficiency Of Klf4 Compromises The Lung Function In An Acute Mouse Model Of Allergic Asthma, Jeanette A. Nimpong, Wintana Gebregziabher, Udai P. Singh, Prakash Nagarkatti, Mitzi Nagarkatti, Johnie Hodge, Chunming Liu, Daping Fan, Walden Ai

Molecular and Cellular Biochemistry Faculty Publications

Asthma is a chronic inflammatory disease of the airways and the mechanisms are not fully understood. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of monocytes, granulocyte and myeloid cells at early stage of differentiation. They possess phenotypic plasticity and regulate airway inflammation. We recently reported that Kruppel-like factor 4 (KLF4) regulates MDSC differentiation into fibrocytes, emerging effectors in chronic inflammation. However, the role of KLF4 in asthma is not known. Thymic stromal lymphopoietin (TSLP) is an epithelial cell-derived cytokine and a key initiator of allergic airway inflammation. Given the fact that TSLP promotes Th2 cytokine production that increases MDSC …

Tox Regulates Growth, Dna Repair, And Genomic Instability In T-Cell Acute Lymphoblastic Leukemia, Riadh Lobbardi, Jordan Pinder, Barbara Martinez-Pastor, Marina Theodorou, Jessica S. Blackburn, Brian J. Abraham, Yuka Namiki, Marc Mansour, Nouran S. Abdelfattah, Aleksey Molodtsov, Gabriela Alexe, Debra Toiber, Manon De Waard, Esha Jain, Myriam Boukhali, Mattia Lion, Deepak Bhere, Khalid Shah, Alejandro Gutierrez, Kimberly Stegmaier, Lewis B. Silverman, Ruslan I. Sadreyev, John M. Asara, Marjorie A. Oettinger, Wilhelm Haas, A. Thomas Look, Richard A. Young, Raul Mostoslavsky, Graham Dellaire, David M. Langenau

Molecular and Cellular Biochemistry Faculty Publications

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of thymocytes. Using a transgenic screen in zebrafish, thymocyte selection–associated high mobility group box protein (TOX) was uncovered as a collaborating oncogenic driver that accelerated T-ALL onset by expanding the initiating pool of transformed clones and elevating genomic instability. TOX is highly expressed in a majority of human T-ALL and is required for proliferation and continued xenograft growth in mice. Using a wide array of functional analyses, we uncovered that TOX binds directly to KU70/80 and suppresses recruitment of this complex to DNA breaks to inhibit nonhomologous end joining (NHEJ) repair. …

Nanoparticle Delivery Of Mir-34a Eradicates Long-Term-Cultured Breast Cancer Stem Cells Via Targeting C22orf28 Directly, Xiaoti Lin, Weiyu Chen, Fengqin Wei, Binhua P. Zhou, Mien-Chie Hung, Xiaoming Xie

Molecular and Cellular Biochemistry Faculty Publications

Rationale: Cancer stem cells (CSCs) have been implicated as the seeds of therapeutic resistance and metastasis, due to their unique abilities of self-renew, wide differentiation potentials and resistance to most conventional therapies. It is a proactive strategy for cancer therapy to eradicate CSCs. Methods: Tumor tissue-derived breast CSCs (BCSC), including XM322 and XM607, were isolated by fluorescence-activated cell sorting (FACS); while cell line-derived BCSC, including MDA-MB-231.SC and MCF-7.SC, were purified by magnetic-activated cell sorting (MACS). Analyses of microRNA and mRNA expression array profiles were performed in multiple breast cell lines. The mentioned nanoparticles were constructed following the standard molecular cloning …

The Molecular Mechanism Of N-Acetylglucosamine Side-Chain Attachment To The Lancefield Group A Carbohydrate In Streptococcus Pyogenes, Jeffrey Rush, Rebecca J. Edgar, Pan Deng, Jing Chen, Haining Zhu, Nina M. Van Sorge, Andrew J. Morris, Konstantin V. Korotkov, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

In many Lactobacillales species (i.e. lactic acid bacteria), peptidoglycan is decorated by polyrhamnose polysaccharides that are critical for cell envelope integrity and cell shape and also represent key antigenic determinants. Despite the biological importance of these polysaccharides, their biosynthetic pathways have received limited attention. The important human pathogen, Streptococcus pyogenes, synthesizes a key antigenic surface polymer, the Lancefield group A carbohydrate (GAC). GAC is covalently attached to peptidoglycan and consists of a polyrhamnose polymer, with N-acetylglucosamine (GlcNAc) side chains, which is an essential virulence determinant. The molecular details of the mechanism of polyrhamnose modification with GlcNAc are …

Stabilization Of The Transcription Factors Slug And Twist By The Deubiquitinase Dub3 Is A Key Requirement For Tumor Metastasis, Yiwei Lin, Yu Wang, Qing Shi, Qian Yu, Cuicui Liu, Jing Feng, Jiong Deng, B. Mark Evers, Binhua P. Zhou, Yadi Wu

Molecular and Cellular Biochemistry Faculty Publications

The Epithelial-mesenchymal transition (EMT) represents a cellular de-differentiation process that provides cells with the increased plasticity required during embryonic development, tissue remodeling, wound healing and metastasis. Slug and Twist are two key EMT transcription factors (EMT-TFs) that are tightly regulated via ubiquitination and degradation. How Slug and Twist escape degradation and become stabilized in cancer cells remains unclear. One plausible mechanism of Slug and Twist stabilization involves removal of ubiquitin by deubiquitinases (DUBs). In this study, we identified Dub3 as a novel DUB for both Slug and Twist. We further found that Dub3 overexpression increased Slug and Twist protein levels …

Clinical And Experimental Studies Of A Novel P525r Fus Mutation In Amyotrophic Lateral Sclerosis, Lisha Kuang, Marisa Kamelgarn, Alexandra Arenas, Jozsef Gal, Deborah Taylor, Weiming Gong, Martin Brown, Daret St. Clair, Edward J. Kasarskis, Haining Zhu

Molecular and Cellular Biochemistry Faculty Publications

Objective: To describe the clinical features of a novel fused in sarcoma (FUS) mutation in a young adult female amyotrophic lateral sclerosis (ALS) patient with rapid progression of weakness and to experimentally validate the consequences of the P525R mutation in cellular neuronal models.

Methods: We conducted sequencing of genomic DNA from the index patient and her family members. Immunocytochemistry was performed in various cellular models to determine whether the newly identified P525R mutant FUS protein accumulated in cytoplasmic inclusions. Clinical features of the index patient were compared with 19 other patients with ALS carrying the P525L mutation in the same …