Medical Molecular Biology Commons^™

Extended-Synaptotagmin-1 And -2 Control T Cell Signaling And Function, Nathalia Benavides, Claudio G. Giraudo

Department of Microbiology and Immunology Faculty Papers

Upon T-cell activation, the levels of the secondary messenger diacylglycerol (DAG) at the plasma membrane need to be controlled to ensure appropriate T-cell receptor signaling and T-cell functions. Extended-Synaptotagmins (E-Syts) are a family of inter-organelle lipid transport proteins that bridge the endoplasmic reticulum and the plasma membrane. In this study, we identify a novel regulatory mechanism of DAG-mediated signaling for T-cell effector functions based on E-Syt proteins. We demonstrate that E-Syts downmodulate T-cell receptor signaling, T-cell-mediated cytotoxicity, degranulation, and cytokine production by reducing plasma membrane levels of DAG. Mechanistically, E-Syt2 predominantly modulates DAG levels at the plasma membrane in resting-state …

Genetic Separation Of Brca1 Functions Reveal Mutation-Dependent Polθ Vulnerabilities, John J. Krais, David J. Glass, Ilse Chudoba, Yifan Wang, Wanjuan Feng, Dennis Simpson, Pooja Patel, Zemin Liu, Ryan Neumann-Domer, Robert G. Betsch, Andrea J. Bernhardy, Alice M. Bradbury, Jason Conger, Wei-Ting Yueh, Joseph Nacson, Richard T. Pomerantz, Gaorav P. Gupta, Joseph R. Testa, Neil Johnson

Department of Biochemistry and Molecular Biology Faculty Papers

Homologous recombination (HR)-deficiency induces a dependency on DNA polymerase theta (Polθ/Polq)-mediated end joining, and Polθ inhibitors (Polθi) are in development for cancer therapy. BRCA1 and BRCA2 deficient cells are thought to be synthetic lethal with Polθ, but whether distinct HR gene mutations give rise to equivalent Polθ-dependence, and the events that drive lethality, are unclear. In this study, we utilized mouse models with separate Brca1 functional defects to mechanistically define Brca1-Polθ synthetic lethality. Surprisingly, homozygous Brca1 mutant, Polq−/− cells were viable, but grew slowly and had chromosomal instability. Brca1 mutant cells proficient in DNA end resection were …

Identification Of A Β-Arrestin-Biased Negative Allosteric Modulator For The Β2-Adrenergic Receptor, Michael Ippolito, Francesco De Pascali, Nathan Hopfinger, Konstantin E. Komolov, Daniela Laurinavichyute, Poli Adi Narayana Reddy, Leon A. Sakkal, Kyle Z. Rajkowski, Ajay P. Nayak, Justin Lee, Jordan Lee, Gaoyuan Cao, Preston S. Donover, Melvin Reichman, Stevens. An, Joseph M. Salvino, Raymond B. Penn, Roger S S. Armen, Charles P. Scott, Jeffrey L. Benovic

Department of Biochemistry and Molecular Biology Faculty Papers

Catecholamine-stimulated β2-adrenergic receptor (β2AR) signaling via the canonical Gs–adenylyl cyclase–cAMP–PKA pathway regulates numerous physiological functions, including the therapeutic effects of exogenous β-agonists in the treatment of airway disease. β2AR signaling is tightly regulated by GRKs and β-arrestins, which together promote β2AR desensitization and internalization as well as downstream signaling, often antithetical to the canonical pathway. Thus, the ability to bias β2AR signaling toward the Gs pathway while avoiding β-arrestin-mediated effects may provide a strategy to improve the functional consequences of β2AR activation. Since attempts to develop Gs-biased agonists and allosteric modulators for the β2AR have been largely unsuccessful, here we …

The Impact Of Essential Trace Elements On Ovarian Response And Reproductive Outcomes Following Single Euploid Embryo Transfer, Roberto Gonzalez-Martin, Andrea Palomar, Alicia Quiñonero, Nuria Pellicer, Rocio Fernandez-Saavedra, Estefania Conde-Vilda, Alberto J Quejido, Christine Whitehead, Richard T. Scott, Francisco Dominguez

Department of Medicine Faculty Papers

Essential trace elements are required in extremely small amounts and obtained through diet. This research focuses on detecting major trace elements in different biofluids of sixty women undergoing ICSI with PGT-A and SET/FET at IVI-RMA, New Jersey, and assessing their impact on their IVF outcomes. Urine, plasma, and follicular fluid samples were collected on the vaginal oocyte retrieval day to measure the concentrations of eight essential trace elements (copper, zinc, molybdenum, lithium, selenium, manganese, chromium, and iron) using ICP-MS. After analysis, ovarian response and preimplantation outcomes had significant positive associations with both copper alone and the copper/zinc ratio in the …

Bone Growth Induction In Mucopolysaccharidosis Iva Mouse, Estera Rintz, Angélica María Herreño-Pachón, Betul Celik, Fnu Nidhi, Shaukat Khan, Eliana Benincore-Flórez, Shunji Tomatsu

Department of Pediatrics Faculty Papers

Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is caused by a deficiency of the N-acetylgalactosamine-6-sulfate-sulfatase (GALNS) enzyme, leading to the accumulation of glycosaminoglycans (GAG), keratan sulfate (KS) and chondroitin-6-sulfate (C6S), mainly in cartilage and bone. This lysosomal storage disorder (LSD) is characterized by severe systemic skeletal dysplasia. To this date, none of the treatment options for the MPS IVA patients correct bone pathology. Enzyme replacement therapy with elosulfase alpha provides a limited impact on bone growth and skeletal lesions in MPS IVA patients. To improve bone pathology, we propose a novel gene therapy with a small peptide as a growth-promoting …

Starvation Sensing By Mycobacterial Rela/Spot Homologue Through Constitutive Surveillance Of Translation, Yunlong Li, Soneya Majumdar, Ryan Treen, Manjuli R. Sharma, Jamie Corro, Howard B. Gamper, Swati R. Manjari, Jerome Prusa, Nilesh K. Banavali, Christina L. Stallings, Ya-Ming Hou, Rajendra K. Agrawal, Anil K. Ojha

Department of Biochemistry and Molecular Biology Faculty Papers

The stringent response, which leads to persistence of nutrient-starved mycobacteria, is induced by activation of the RelA/SpoT homolog (Rsh) upon entry of a deacylated-tRNA in a translating ribosome. However, the mechanism by which Rsh identifies such ribosomes in vivo remains unclear. Here, we show that conditions inducing ribosome hibernation result in loss of intracellular Rsh in a Clp protease-dependent manner. This loss is also observed in nonstarved cells using mutations in Rsh that block its interaction with the ribosome, indicating that Rsh association with the ribosome is important for Rsh stability. The cryo-EM structure of the Rsh-bound 70S ribosome in …

Changes In Nascent Chromatin Structure Regulate Activation Of The Pro-Fibrotic Transcriptome And Myofibroblast Emergence In Organ Fibrosis, Morgan D. Basta, Svetlana Petruk, Ross Summer, Joel Rosenbloom, Peter J. Wermuth, Edward J. Macarak, Alex V. Levin, Alexander Mazo, Janice L. Walker

Department of Biochemistry and Molecular Biology Faculty Papers

Cell reprogramming to a myofibroblast responsible for the pathological accumulation of extracellular matrix is fundamental to the onset of fibrosis. Here, we explored how condensed chromatin structure marked by H3K72me3 becomes modified to allow for activation of repressed genes to drive emergence of myofibroblasts. In the early stages of myofibroblast precursor cell differentiation, we discovered that H3K27me3 demethylase enzymes UTX/KDM6B creates a delay in the accumulation of H3K27me3 on nascent DNA revealing a period of decondensed chromatin structure. This period of decondensed nascent chromatin structure allows for binding of pro-fibrotic transcription factor, Myocardin-related transcription factor A (MRTF-A) to nascent DNA. …

Candidate Variants In Dna Replication And Repair Genes In Early-Onset Renal Cell Carcinoma Patients Referred For Germline Testing, Elena V. Demidova, Ilya G. Serebriiskii, Ramilia Vlasenkova, Simon Kelow, Mark D. Andrake, Tiffiney R. Hartman, Tatiana Kent, James Virtucio, Gail L. Rosen, Richard T. Pomerantz, Roland L. Dunbrack, Erica A. Golemis, Michael J. Hall, David Y.T. Chen, Mary B. Daly, Sanjeevani Arora

Department of Biochemistry and Molecular Biology Faculty Papers

Background: Early-onset renal cell carcinoma (eoRCC) is typically associated with pathogenic germline variants (PGVs) in RCC familial syndrome genes. However, most eoRCC patients lack PGVs in familial RCC genes and their genetic risk remains undefined.

Methods: Here, we analyzed biospecimens from 22 eoRCC patients that were seen at our institution for genetic counseling and tested negative for PGVs in RCC familial syndrome genes.

Results: Analysis of whole-exome sequencing (WES) data found enrichment of candidate pathogenic germline variants in DNA repair and replication genes, including multiple DNA polymerases. Induction of DNA damage in peripheral blood monocytes (PBMCs) significantly elevated numbers of …

Mechanisms Of Chromosomal Instability (Cin) Tolerance In Aggressive Tumors: Surviving The Genomic Chaos, Brittiny Dhital, Veronica Rodriguez-Bravo

Student Papers, Posters & Projects

Chromosomal instability (CIN) is a pervasive feature of human cancers involved in tumor initiation and progression and which is found elevated in metastatic stages. CIN can provide survival and adaptation advantages to human cancers. However, too much of a good thing may come at a high cost for tumor cells as excessive degree of CIN-induced chromosomal aberrations can be detrimental for cancer cell survival and proliferation. Thus, aggressive tumors adapt to cope with ongoing CIN and most likely develop unique susceptibilities that can be their Achilles' heel. Determining the differences between the tumor-promoting and tumor-suppressing effects of CIN at the …

Protocol To Identify The Core Gene Supported By An Essential Gene In E. Coli Bacteria Using A Genome-Wide Suppressor Screen, Isao Masuda, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

We describe here a genome-wide screening approach to identify the most critical core reaction among a network of many that are supported by an essential gene to establish cell viability. We describe steps for maintenance plasmid construction, knockout cell construction, and phenotype validation. We then detail isolation of suppressors, whole-genome sequencing analysis, and reconstruction of CRISPR mutants. We focus on E. coli trmD, which encodes an essential methyl transferase that synthesizes m1G37 on the 3'-side of the tRNA anticodon. For complete details on the use and execution of this protocol, please refer to Masuda et al. (2022).

Acute Acat1/Soat1 Blockade Increases Mam Cholesterol And Strengthens Er-Mitochondria Connectivity., Taylor C Harned, Radu V Stan, Ze Cao, Rajarshi Chakrabarti, Henry N Higgs, Catherine C Y Chang, Ta Yuan Chang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cholesterol is a key component of all mammalian cell membranes. Disruptions in cholesterol metabolism have been observed in the context of various diseases, including neurodegenerative disorders such as Alzheimer's disease (AD). The genetic and pharmacological blockade of acyl-CoA:cholesterol acyltransferase 1/sterol O-acyltransferase 1 (ACAT1/SOAT1), a cholesterol storage enzyme found on the endoplasmic reticulum (ER) and enriched at the mitochondria-associated ER membrane (MAM), has been shown to reduce amyloid pathology and rescue cognitive deficits in mouse models of AD. Additionally, blocking ACAT1/SOAT1 activity stimulates autophagy and lysosomal biogenesis; however, the exact molecular connection between the ACAT1/SOAT1 blockade and these observed benefits remain …

Role Of Ribosome Recycling Factor In Natural Termination And Translational Coupling As A Ribosome Releasing Factor, Yoshio Inokuchi, Fabio Quaglia, Akikazu Hirashima, Yoshihiro Yamamoto, Hideko Kaji, Akira Kaji

Department of Biochemistry and Molecular Biology Faculty Papers

The role of ribosome recycling factor (RRF) of E. coli was studied in vivo and in vitro. We used the translational coupling without the Shine-Dalgarno sequence of downstream ORF (d-ORF) as a model system of the RRF action in natural termination of protein synthesis. For the in vivo studies we used the translational coupling by the adjacent coat and lysis genes of RNA phage GA sharing the termination and initiation (UAAUG) and temperature sensitive RRF. The d-ORF translation was measured by the expression of the reporter lacZ gene connected to the 5'-terminal part of the lysis gene. The results showed …

Parp1 Associates With R-Loops To Promote Their Resolution And Genome Stability, Natalie Laspata, Parminder Kaur, Sofiane Yacine Mersaoui, Daniela Muoio, Zhiyan Silvia Liu, Maxwell Henry Bannister, Hai Dang Nguyen, Caroline Curry, John M. Pascal, Guy G. Poirier, Hong Wang, Jean-Yves Masson, Elise Fouquerel

Student Papers, Posters & Projects

PARP1 is a DNA-dependent ADP-Ribose transferase with ADP-ribosylation activity that is triggered by DNA breaks and non-B DNA structures to mediate their resolution. PARP1 was also recently identified as a component of the R-loop-associated protein-protein interaction network, suggesting a potential role for PARP1 in resolving this structure. R-loops are three-stranded nucleic acid structures that consist of a RNA-DNA hybrid and a displaced non-template DNA strand. R-loops are involved in crucial physiological processes but can also be a source of genome instability if persistently unresolved. In this study, we demonstrate that PARP1 binds R-loops in vitro and associates with R-loop formation …

Harnessing Transcriptionally Driven Chromosomal Instability Adaptation To Target Therapy-Refractory Lethal Prostate Cancer., Brittiny Dhital, Sandra Santasusagna, Perumalraja Kirthika, Michael Xu, Peiyao Li, Marc Carceles-Cordon, Rajesh K. Soni, Zhuoning Li, Ronald C. Hendrickson, Matthew J. Schiewer, William K. Kelly, Cora N. Sternberg, Jun Luo, Amaia Lujambio, Carlos Cordon-Cardo, Monica Alvarez-Fernandez, Marcos Malumbres, Haojie Huang, Adam Ertel, Josep Domingo-Domenech, Veronica Rodriguez-Bravo

Kimmel Cancer Center Papers, Presentations, and Grand Rounds

Metastatic prostate cancer (PCa) inevitably acquires resistance to standard therapy preceding lethality. Here, we unveil a chromosomal instability (CIN) tolerance mechanism as a therapeutic vulnerability of therapy-refractory lethal PCa. Through genomic and transcriptomic analysis of patient datasets, we find that castration and chemotherapy-resistant tumors display the highest CIN and mitotic kinase levels. Functional genomics screening coupled with quantitative phosphoproteomics identify MASTL kinase as a survival vulnerability specific of chemotherapy-resistant PCa cells. Mechanistically, MASTL upregulation is driven by transcriptional rewiring mechanisms involving the non-canonical transcription factors androgen receptor splice variant 7 and E2F7 in a circuitry that restrains deleterious CIN and …

Semi-Quantitative Detection Of Pseudouridine Modifications And Type I/Ii I/Ii Hypermodifications In Human Mrnas Using Direct Long-Read Sequencing, Sepideh Tavakoli, Mohammad Nabizadeh, Amr Makhamreh, Howard Gamper, Caroline A Mccormick, Neda K Rezapour, Ya-Ming Hou, Meni Wanunu, Sara H Rouhanifard

Department of Biochemistry and Molecular Biology Faculty Papers

Here, we develop and apply a semi-quantitative method for the high-confidence identification of pseudouridylated sites on mammalian mRNAs via direct long-read nanopore sequencing. A comparative analysis of a modification-free transcriptome reveals that the depth of coverage and specific k-mer sequences are critical parameters for accurate basecalling. By adjusting these parameters for high-confidence U-to-C basecalling errors, we identify many known sites of pseudouridylation and uncover previously unreported uridine-modified sites, many of which fall in k-mers that are known targets of pseudouridine synthases. Identified sites are validated using 1000-mer synthetic RNA controls bearing a single pseudouridine in the center position, demonstrating systematic …

Disruption Of The Interaction Between Mutationally Activated Gαq And Gβγ Attenuates Aberrant Signaling, Jenna L Aumiller, Philip B Wedegaertner

Department of Biochemistry and Molecular Biology Faculty Papers

Heterotrimeric G protein stimulation via G protein-coupled receptors promotes downstream proliferative signaling. Mutations can occur in Gα proteins which prevent GTP hydrolysis; this allows the G proteins to signal independently of G protein-coupled receptors and can result in various cancers, such as uveal melanoma (UM). Most UM cases harbor Q209L, Q209P, or R183C mutations in Gαq/11 proteins, rendering the proteins constitutively active (CA). Although it is generally thought that active, GTP-bound Gα subunits are dissociated from and signal independently of Gβγ, accumulating evidence indicates that some CA Gα mutants, such as Gαq/11, retain binding to Gβγ, and this interaction is …

Differentiating Pc12 Cells To Evaluate Neurite Densities Through Live-Cell Imaging, Jordyn Karliner, Diane E Merry

Department of Biochemistry and Molecular Biology Faculty Papers

Although PC12 cells are a valuable tool in neuroscience research, previously published PC12 cell differentiation techniques fail to consider the variability in differentiation rates between different PC12 cell strains and clonal variants. Here, we present a comprehensive protocol to differentiate PC12 cells into equivalent neurite densities through live-cell imaging for morphological, immunocytochemical, and biochemical analyses. We detail steps on optimized substrate coating, plating techniques, culture media, validation steps, and quantification techniques.