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Full-Text Articles in Life Sciences

Engineered Nls-Chimera Downregulates Expression Of Aggregation-Prone Endogenous Fus, Miyuki Hayashi, Amandeep Girdhar, Ying-Hui Ko, Kevin Kim, Jacquelyn Depierro, Joseph R. Buchler, Nikhita Arunprakash, Aditya Bajaj, Gino Cingolani, Lin Guo Sep 2024

Engineered Nls-Chimera Downregulates Expression Of Aggregation-Prone Endogenous Fus, Miyuki Hayashi, Amandeep Girdhar, Ying-Hui Ko, Kevin Kim, Jacquelyn Depierro, Joseph R. Buchler, Nikhita Arunprakash, Aditya Bajaj, Gino Cingolani, Lin Guo

Department of Biochemistry and Molecular Biology Faculty Papers

Importin β-superfamily nuclear import receptors (NIRs) mitigate mislocalization and aggregation of RNA-binding proteins (RBPs), like FUS and TDP-43, which are implicated in neurodegenerative diseases. NIRs potently disaggregate RBPs by recognizing their nuclear localization signal (NLS). However, disease-causing mutations in NLS compromise NIR binding and activity. Here, we define features that characterize the anti-aggregation activity of NIR and NLS. We find that high binding affinity between NIR and NLS, and optimal NLS location relative to the aggregating domain plays a role in determining NIR disaggregation activity. A designed FUS chimera (FUSIBB), carrying the importin β binding (IBB) domain, is …


Structural Basis For Substrate Binding And Selection By Human Mitochondrial Rna Polymerase, Karl Herbine, Ashok Nayak, Dmitry Temiakov Aug 2024

Structural Basis For Substrate Binding And Selection By Human Mitochondrial Rna Polymerase, Karl Herbine, Ashok Nayak, Dmitry Temiakov

Department of Biochemistry and Molecular Biology Faculty Papers

The mechanism by which RNAP selects cognate substrates and discriminates between deoxy and ribonucleotides is of fundamental importance to the fidelity of transcription. Here, we present cryo-EM structures of human mitochondrial transcription elongation complexes that reveal substrate ATP bound in Entry and Insertion Sites. In the Entry Site, the substrate binds along the O helix of the fingers domain of mtRNAP but does not interact with the templating DNA base. Interactions between RNAP and the triphosphate moiety of the NTP in the Entry Site ensure discrimination against nucleosides and their diphosphate and monophosphate derivatives but not against non-cognate rNTPs and …


G12/13 Signaling In Asthma, Elizabeth L. Mcduffie, Reynold A Panettieri, Charles P. Scott Aug 2024

G12/13 Signaling In Asthma, Elizabeth L. Mcduffie, Reynold A Panettieri, Charles P. Scott

Department of Biochemistry and Molecular Biology Faculty Papers

Shortening of airway smooth muscle and bronchoconstriction are pathognomonic for asthma. Airway shortening occurs through calcium-dependent activation of myosin light chain kinase, and RhoA-dependent calcium sensitization, which inhibits myosin light chain phosphatase. The mechanism through which pro-contractile stimuli activate calcium sensitization is poorly understood. Our review of the literature suggests that pro-contractile G protein coupled receptors likely signal through G12/13 to activate RhoA and mediate calcium sensitization. This hypothesis is consistent with the effects of pro-contractile agonists on RhoA and Rho kinase activation, actin polymerization and myosin light chain phosphorylation. Recognizing the likely role of G12/13 signaling in the pathophysiology …


Mutant Androgen Receptor Induces Neurite Loss And Senescence Independently Of Are Binding In A Neuronal Model Of Sbma, Jordyn Karliner, Y Liu, Diane Merry Jul 2024

Mutant Androgen Receptor Induces Neurite Loss And Senescence Independently Of Are Binding In A Neuronal Model Of Sbma, Jordyn Karliner, Y Liu, Diane Merry

Department of Biochemistry and Molecular Biology Faculty Papers

Spinal and bulbar muscular atrophy (SBMA) is a slowly progressing neuromuscular disease caused by a polyglutamine (polyQ)-encoding CAG trinucleotide repeat expansion in the androgen receptor (AR) gene, leading to AR aggregation, lower motor neuron death, and muscle atrophy. AR is a ligand-activated transcription factor that regulates neuronal architecture and promotes axon regeneration; however, whether AR transcriptional functions contribute to disease pathogenesis is not fully understood. Using a differentiated PC12 cell model of SBMA, we identified dysfunction of polyQ-expanded AR in its regulation of neurite growth and maintenance. Specifically, we found that in the presence of androgens, polyQ-expanded AR inhibited neurite …


Frontotemporal Dementia-Like Disease Progression Elicited By Seeded Aggregation And Spread Of Fus, Sonia Vazquez-Sanchez, Britt Tilkin, Fatima Gasset-Rosa, Sitao Zhang, Diana Piol, Melissa Mcalonis-Downes, Jonathan Artates, Noe Govea-Perez, Yana Verresen, Lin Guo, Don Cleveland, James Shorter, Sandrine Da Cruz Jun 2024

Frontotemporal Dementia-Like Disease Progression Elicited By Seeded Aggregation And Spread Of Fus, Sonia Vazquez-Sanchez, Britt Tilkin, Fatima Gasset-Rosa, Sitao Zhang, Diana Piol, Melissa Mcalonis-Downes, Jonathan Artates, Noe Govea-Perez, Yana Verresen, Lin Guo, Don Cleveland, James Shorter, Sandrine Da Cruz

Department of Biochemistry and Molecular Biology Faculty Papers

RNA binding proteins have emerged as central players in the mechanisms of many neurodegenerative diseases. In particular, a proteinopathy of fused in sarcoma (FUS) is present in some instances of familial Amyotrophic lateral sclerosis (ALS) and about 10% of sporadic Frontotemporal lobar degeneration (FTLD). Here we establish that focal injection of sonicated human FUS fibrils into brains of mice in which ALS-linked mutant or wild-type human FUS replaces endogenous mouse FUS is sufficient to induce focal cytoplasmic mislocalization and aggregation of mutant and wild-type FUS which with time spreads to distal regions of the brain. Human FUS fibril-induced FUS aggregation …


Predictive And Prognostic Biomarkers And Tumor Antigens For Targeted Therapy In Urothelial Carcinoma, Aditya Eturi, Amman Bhasin, Kevin Zarrabi, William Tester Apr 2024

Predictive And Prognostic Biomarkers And Tumor Antigens For Targeted Therapy In Urothelial Carcinoma, Aditya Eturi, Amman Bhasin, Kevin Zarrabi, William Tester

Department of Medical Oncology Faculty Papers

Urothelial carcinoma (UC) is the fourth most prevalent cancer amongst males worldwide. While patients with non-muscle-invasive disease have a favorable prognosis, 25% of UC patients present with locally advanced disease which is associated with a 10-15% 5-year survival rate and poor overall prognosis. Muscle-invasive bladder cancer (MIBC) is associated with about 50% 5 year survival when treated by radical cystectomy or trimodality therapy; stage IV disease is associated with 10-15% 5 year survival. Current therapeutic modalities for MIBC include neoadjuvant chemotherapy, surgery and/or chemoradiation, although patients with relapsed or refractory disease have a poor prognosis. However, the rapid success of …


Discovery Of A Small-Molecule Inhibitor That Traps Polθ On Dna And Synergizes With Parp Inhibitors, William Fried, Mrityunjay Tyagi, Leonid Minakhin, Gurushankar Chandramouly, Taylor Tredinnick, Mercy Ramanjulu, William Auerbacher, Marissa L Calbert, Timur Rusanov, Trung Hoang, Nikita Borisonnik, Robert Betsch, John Krais, Yifan Wang, Umeshkumar Vekariya, John Gordon, George Morton, Tatiana Kent, Tomasz Skorski, Neil Johnson, Wayne Childers, Xiaojiang Chen, Richard Pomerantz Apr 2024

Discovery Of A Small-Molecule Inhibitor That Traps Polθ On Dna And Synergizes With Parp Inhibitors, William Fried, Mrityunjay Tyagi, Leonid Minakhin, Gurushankar Chandramouly, Taylor Tredinnick, Mercy Ramanjulu, William Auerbacher, Marissa L Calbert, Timur Rusanov, Trung Hoang, Nikita Borisonnik, Robert Betsch, John Krais, Yifan Wang, Umeshkumar Vekariya, John Gordon, George Morton, Tatiana Kent, Tomasz Skorski, Neil Johnson, Wayne Childers, Xiaojiang Chen, Richard Pomerantz

Department of Biochemistry and Molecular Biology Faculty Papers

The DNA damage response (DDR) protein DNA Polymerase θ (Polθ) is synthetic lethal with homologous recombination (HR) factors and is therefore a promising drug target in BRCA1/2 mutant cancers. We discover an allosteric Polθ inhibitor (Polθi) class with 4-6 nM IC50 that selectively kills HR-deficient cells and acts synergistically with PARP inhibitors (PARPi) in multiple genetic backgrounds. X-ray crystallography and biochemistry reveal that Polθi selectively inhibits Polθ polymerase (Polθ-pol) in the closed conformation on B-form DNA/DNA via an induced fit mechanism. In contrast, Polθi fails to inhibit Polθ-pol catalytic activity on A-form DNA/RNA in which the enzyme binds in …


Biomarkers For Managing Neurodegenerative Diseases, Lara Cheslow, Adam E. Snook, Scott A. Waldman Mar 2024

Biomarkers For Managing Neurodegenerative Diseases, Lara Cheslow, Adam E. Snook, Scott A. Waldman

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Neurological disorders are the leading cause of cognitive and physical disability worldwide, affecting 15% of the global population. Due to the demographics of aging, the prevalence of neurological disorders, including neurodegenerative diseases, will double over the next two decades. Unfortunately, while available therapies provide symptomatic relief for cognitive and motor impairment, there is an urgent unmet need to develop disease-modifying therapies that slow the rate of pathological progression. In that context, biomarkers could identify at-risk and prodromal patients, monitor disease progression, track responses to therapy, and parse the causality of molecular events to identify novel targets for further clinical investigation. …


Structural Basis For Dna Proofreading, Gina Buchel, Ashok Nayak, Karl Herbine, Azadeh Sarfallah, Viktoriia Sokolova, Angelica Zamudio-Ochoa, Dmitry Temiakov Dec 2023

Structural Basis For Dna Proofreading, Gina Buchel, Ashok Nayak, Karl Herbine, Azadeh Sarfallah, Viktoriia Sokolova, Angelica Zamudio-Ochoa, Dmitry Temiakov

Department of Biochemistry and Molecular Biology Faculty Papers

DNA polymerase (DNAP) can correct errors in DNA during replication by proofreading, a process critical for cell viability. However, the mechanism by which an erroneously incorporated base translocates from the polymerase to the exonuclease site and the corrected DNA terminus returns has remained elusive. Here, we present an ensemble of nine high-resolution structures representing human mitochondrial DNA polymerase Gamma, Polγ, captured during consecutive proofreading steps. The structures reveal key events, including mismatched base recognition, its dissociation from the polymerase site, forward translocation of DNAP, alterations in DNA trajectory, repositioning and refolding of elements for primer separation, DNAP backtracking, and displacement …