Other search tools

About this data

The publication data currently available has been vetted by Vanderbilt faculty, staff, administrators and trainees. The data itself is retrieved directly from NCBI's PubMed and is automatically updated on a weekly basis to ensure accuracy and completeness.

If you have any questions or comments, please contact us.

Results: 1 to 10 of 262

Publication Record

Connections

Disrupted structure and aberrant function of CHIP mediates the loss of motor and cognitive function in preclinical models of SCAR16.
Shi CH, Rubel C, Soss SE, Sanchez-Hodge R, Zhang S, Madrigal SC, Ravi S, McDonough H, Page RC, Chazin WJ, Patterson C, Mao CY, Willis MS, Luo HY, Li YS, Stevens DA, Tang MB, Du P, Wang YH, Hu ZW, Xu YM, Schisler JC
(2018) PLoS Genet 14: e1007664
MeSH Terms: Animals, Behavior, Animal, CRISPR-Cas Systems, Cognition, Disease Models, Animal, Female, Humans, Male, Mice, Mice, Inbred C57BL, Models, Molecular, Motor Activity, Mutagenesis, Site-Directed, Phenotype, Point Mutation, Protein Domains, Protein Multimerization, Rats, Rats, Sprague-Dawley, Spinocerebellar Ataxias, Ubiquitin-Protein Ligases
Show Abstract · Added March 26, 2019
CHIP (carboxyl terminus of heat shock 70-interacting protein) has long been recognized as an active member of the cellular protein quality control system given the ability of CHIP to function as both a co-chaperone and ubiquitin ligase. We discovered a genetic disease, now known as spinocerebellar autosomal recessive 16 (SCAR16), resulting from a coding mutation that caused a loss of CHIP ubiquitin ligase function. The initial mutation describing SCAR16 was a missense mutation in the ubiquitin ligase domain of CHIP (p.T246M). Using multiple biophysical and cellular approaches, we demonstrated that T246M mutation results in structural disorganization and misfolding of the CHIP U-box domain, promoting oligomerization, and increased proteasome-dependent turnover. CHIP-T246M has no ligase activity, but maintains interactions with chaperones and chaperone-related functions. To establish preclinical models of SCAR16, we engineered T246M at the endogenous locus in both mice and rats. Animals homozygous for T246M had both cognitive and motor cerebellar dysfunction distinct from those observed in the CHIP null animal model, as well as deficits in learning and memory, reflective of the cognitive deficits reported in SCAR16 patients. We conclude that the T246M mutation is not equivalent to the total loss of CHIP, supporting the concept that disease-causing CHIP mutations have different biophysical and functional repercussions on CHIP function that may directly correlate to the spectrum of clinical phenotypes observed in SCAR16 patients. Our findings both further expand our basic understanding of CHIP biology and provide meaningful mechanistic insight underlying the molecular drivers of SCAR16 disease pathology, which may be used to inform the development of novel therapeutics for this devastating disease.
0 Communities
1 Members
0 Resources
MeSH Terms
Helicobacter pylori pathogen regulates p14ARF tumor suppressor and autophagy in gastric epithelial cells.
Horvat A, Noto JM, Ramatchandirin B, Zaika E, Palrasu M, Wei J, Schneider BG, El-Rifai W, Peek RM, Zaika AI
(2018) Oncogene 37: 5054-5065
MeSH Terms: Antigens, Bacterial, Autophagy, Bacterial Proteins, Cell Line, Tumor, Down-Regulation, Epithelial Cells, Gastric Mucosa, HCT116 Cells, Helicobacter Infections, Helicobacter pylori, Humans, Signal Transduction, Stomach, Stomach Neoplasms, Tumor Suppressor Protein p14ARF, Tumor Suppressor Protein p53, Ubiquitin-Protein Ligases, Up-Regulation, Virulence Factors
Show Abstract · Added September 25, 2018
Infection with Helicobacter pylori is one of the strongest risk factors for development of gastric cancer. Although these bacteria infect approximately half of the world's population, only a small fraction of infected individuals develops gastric malignancies. Interactions between host and bacterial virulence factors are complex and interrelated, making it difficult to elucidate specific processes associated with H. pylori-induced tumorigenesis. In this study, we found that H. pylori inhibits p14ARF tumor suppressor by inducing its degradation. This effect was found to be strain-specific. Downregulation of p14ARF induced by H. pylori leads to inhibition of autophagy in a p53-independent manner in infected cells. We identified TRIP12 protein as E3 ubiquitin ligase that is upregulated by H. pylori, inducing ubiquitination and subsequent degradation of p14ARF protein. Using isogenic H. pylori mutants, we found that induction of TRIP12 is mediated by bacterial virulence factor CagA. Increased expression of TRIP12 protein was found in infected gastric epithelial cells in vitro and human gastric mucosa of H. pylori-infected individuals. In conclusion, our data demonstrate a new mechanism of ARF inhibition that may affect host-bacteria interactions and facilitate tumorigenic transformation in the stomach.
0 Communities
1 Members
0 Resources
19 MeSH Terms
Enhanced Ion Transmission Efficiency up to m/ z 24 000 for MALDI Protein Imaging Mass Spectrometry.
Prentice BM, Ryan DJ, Van de Plas R, Caprioli RM, Spraggins JM
(2018) Anal Chem 90: 5090-5099
MeSH Terms: Animals, Apoproteins, Brain, Ions, Kidney, Molecular Weight, Myoglobin, Proteins, Rats, Signal-To-Noise Ratio, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Ubiquitin
Show Abstract · Added March 22, 2018
The molecular identification of species of interest is an important part of an imaging mass spectrometry (IMS) experiment. The high resolution accurate mass capabilities of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) have recently been shown to facilitate the identification of proteins in matrix-assisted laser desorption/ionization (MALDI) IMS. However, these experiments are typically limited to proteins giving rise to ions of relatively low m/ z due to difficulties transmitting and measuring large molecular weight ions of low charge states. Herein we have modified the source gas manifold of a commercial MALDI FT-ICR MS to regulate the gas flow and pressure to maximize the transmission of large m/ z protein ions through the ion funnel region of the instrument. By minimizing the contribution of off-axis gas disruption to ion focusing and maximizing the effective potential wall confining the ions through pressure optimization, the signal-to-noise ratios (S/N) of most protein species were improved by roughly 1 order of magnitude compared to normal source conditions. These modifications enabled the detection of protein standards up to m/ z 24 000 and the detection of proteins from tissue up to m/ z 22 000 with good S/N, roughly doubling the mass range for which high quality protein ion images from rat brain and kidney tissue could be produced. Due to the long time-domain transients (>4 s) required to isotopically resolve high m/ z proteins, we have used these data as part of an FT-ICR IMS-microscopy data-driven image fusion workflow to produce estimated protein images with both high mass and high spatial resolutions.
0 Communities
3 Members
0 Resources
12 MeSH Terms
Identification of a ubiquitin-binding interface using Rosetta and DEER.
Tessmer MH, Anderson DM, Pickrum AM, Riegert MO, Moretti R, Meiler J, Feix JB, Frank DW
(2018) Proc Natl Acad Sci U S A 115: 525-530
MeSH Terms: Bacterial Proteins, Crystallography, X-Ray, Electron Spin Resonance Spectroscopy, Models, Molecular, Protein Binding, Protein Domains, Pseudomonas aeruginosa, Ubiquitin
Show Abstract · Added March 17, 2018
ExoU is a type III-secreted cytotoxin expressing A phospholipase activity when injected into eukaryotic target cells by the bacterium The enzymatic activity of ExoU is undetectable in vitro unless ubiquitin, a required cofactor, is added to the reaction. The role of ubiquitin in facilitating ExoU enzymatic activity is poorly understood but of significance for designing inhibitors to prevent tissue injury during infections with strains of producing this toxin. Most ubiquitin-binding proteins, including ExoU, demonstrate a low (micromolar) affinity for monoubiquitin (monoUb). Additionally, ExoU is a large and dynamic protein, limiting the applicability of traditional structural techniques such as NMR and X-ray crystallography to define this protein-protein interaction. Recent advancements in computational methods, however, have allowed high-resolution protein modeling using sparse data. In this study, we combine double electron-electron resonance (DEER) spectroscopy and Rosetta modeling to identify potential binding interfaces of ExoU and monoUb. The lowest-energy scoring model was tested using biochemical, biophysical, and biological techniques. To verify the binding interface, Rosetta was used to design a panel of mutations to modulate binding, including one variant with enhanced binding affinity. Our analyses show the utility of computational modeling when combined with sensitive biological assays and biophysical approaches that are exquisitely suited for large dynamic proteins.
0 Communities
1 Members
0 Resources
8 MeSH Terms
Systemic inflammation is associated with exaggerated skeletal muscle protein catabolism in maintenance hemodialysis patients.
Deger SM, Hung AM, Gamboa JL, Siew ED, Ellis CD, Booker C, Sha F, Li H, Bian A, Stewart TG, Zent R, Mitch WE, Abumrad NN, Ikizler TA
(2017) JCI Insight 2:
MeSH Terms: Adult, Animals, Biomarkers, C-Reactive Protein, Cytokines, Disease Models, Animal, Female, Homeostasis, Humans, Inflammation, Integrin beta1, Kinetics, Male, Mice, Mice, Knockout, Middle Aged, Multivariate Analysis, Muscle Proteins, Muscle, Skeletal, Regression Analysis, Renal Dialysis, Renal Insufficiency, Chronic, SKP Cullin F-Box Protein Ligases, Tripartite Motif Proteins, Ubiquitin-Protein Ligases
Show Abstract · Added March 14, 2018
BACKGROUND - Systemic inflammation and muscle wasting are highly prevalent and coexist in patients on maintenance hemodialysis (MHD). We aimed to determine the effects of systemic inflammation on skeletal muscle protein metabolism in MHD patients.
METHODS - Whole body and skeletal muscle protein turnover were assessed by stable isotope kinetic studies. We incorporated expressions of E1, E214K, E3αI, E3αII, MuRF-1, and atrogin-1 in skeletal muscle tissue from integrin β1 gene KO CKD mice models.
RESULTS - Among 129 patients with mean (± SD) age 47 ± 12 years, 74% were African American, 73% were male, and 22% had diabetes mellitus. Median high-sensitivity C-reactive protein (hs-CRP) concentration was 13 (interquartile range 0.8, 33) mg/l. There were statistically significant associations between hs-CRP and forearm skeletal muscle protein synthesis, degradation, and net forearm skeletal muscle protein balance (P < 0.001 for all). The associations remained statistically significant after adjustment for clinical and demographic confounders, as well as in sensitivity analysis, excluding patients with diabetes mellitus. In attempting to identify potential mechanisms involved in this correlation, we show increased expressions of E1, E214K, E3αI, E3αII, MuRF-1, and atrogin-1 in skeletal muscle tissue obtained from an animal model of chronic kidney disease.
CONCLUSION - These data suggest that systemic inflammation is a strong and independent determinant of skeletal muscle protein homeostasis in MHD patients, providing rationale for further studies using anticytokine therapies in patients with underlying systemic inflammation.
FUNDING - This study was in part supported by NIH grants R01 DK45604 and 1K24 DK62849, the Clinical Translational Science Award UL1-TR000445 from the National Center for Advancing Translational Sciences, the Veterans Administration Merit Award I01 CX000414, the SatelliteHealth Normon Coplon Extramural Grant Program, and the FDA grant 000943.
0 Communities
2 Members
0 Resources
25 MeSH Terms
Ubiquitin turnover and endocytic trafficking in yeast are regulated by Ser57 phosphorylation of ubiquitin.
Lee S, Tumolo JM, Ehlinger AC, Jernigan KK, Qualls-Histed SJ, Hsu PC, McDonald WH, Chazin WJ, MacGurn JA
(2017) Elife 6:
MeSH Terms: Endocytosis, Homeostasis, Phosphoprotein Phosphatases, Phosphorylation, Protein Processing, Post-Translational, Saccharomyces cerevisiae Proteins, Ubiquitin, Yeasts
Show Abstract · Added March 24, 2018
Despite its central role in protein degradation little is known about the molecular mechanisms that sense, maintain, and regulate steady state concentration of ubiquitin in the cell. Here, we describe a novel mechanism for regulation of ubiquitin homeostasis that is mediated by phosphorylation of ubiquitin at the Ser57 position. We find that loss of Ppz phosphatase activity leads to defects in ubiquitin homeostasis that are at least partially attributable to elevated levels of Ser57 phosphorylated ubiquitin. Phosphomimetic mutation at the Ser57 position of ubiquitin conferred increased rates of endocytic trafficking and ubiquitin turnover. These phenotypes are associated with bypass of recognition by endosome-localized deubiquitylases - including Doa4 which is critical for regulation of ubiquitin recycling. Thus, ubiquitin homeostasis is significantly impacted by the rate of ubiquitin flux through the endocytic pathway and by signaling pathways that converge on ubiquitin itself to determine whether it is recycled or degraded in the vacuole.
0 Communities
1 Members
0 Resources
8 MeSH Terms
COPI mediates recycling of an exocytic SNARE by recognition of a ubiquitin sorting signal.
Xu P, Hankins HM, MacDonald C, Erlinger SJ, Frazier MN, Diab NS, Piper RC, Jackson LP, MacGurn JA, Graham TR
(2017) Elife 6:
MeSH Terms: Coat Protein Complex I, Exosomes, Protein Transport, R-SNARE Proteins, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Ubiquitin
Show Abstract · Added March 14, 2018
The COPI coat forms transport vesicles from the Golgi complex and plays a poorly defined role in endocytic trafficking. Here we show that COPI binds K63-linked polyubiquitin and this interaction is crucial for trafficking of a ubiquitinated yeast SNARE (Snc1). Snc1 is a v-SNARE that drives fusion of exocytic vesicles with the plasma membrane, and then recycles through the endocytic pathway to the Golgi for reuse in exocytosis. Removal of ubiquitin from Snc1, or deletion of a β'-COP subunit propeller domain that binds K63-linked polyubiquitin, disrupts Snc1 recycling causing aberrant accumulation in internal compartments. Moreover, replacement of the β'-COP propeller domain with unrelated ubiquitin-binding domains restores Snc1 recycling. These results indicate that ubiquitination, a modification well known to target membrane proteins to the lysosome or vacuole for degradation, can also function as recycling signal to sort a SNARE into COPI vesicles in a non-degradative pathway.
0 Communities
1 Members
0 Resources
7 MeSH Terms
Suppressed ubiquitination of Nrf2 by p47 contributes to Nrf2 activation.
Ha Kim K, Sadikot RT, Yeon Lee J, Jeong HS, Oh YK, Blackwell TS, Joo M
(2017) Free Radic Biol Med 113: 48-58
MeSH Terms: Animals, Disease Models, Animal, HEK293 Cells, Humans, Kelch-Like ECH-Associated Protein 1, Lipopolysaccharides, Mice, NADPH Oxidases, NF-E2-Related Factor 2, Pneumonia, RAW 264.7 Cells, Reactive Oxygen Species, Signal Transduction, Ubiquitination
Show Abstract · Added March 21, 2018
Although critical in phagocytosis in innate immunity, reactive oxygen species (ROS) collaterally inflict damage to host phagocytes because they indiscriminate targets. Since Nrf2 increases the expression of anti-oxidant enzymes that nullifies ROS, ROS activating Nrf2 is a critical negative regulatory step for countering the deleterious effects of ROS. Here, we postulate whether, along with ROS activating Nrf2, NADPH oxidase components also participate in direct activation of Nrf2, contributing to protection from ROS. Our results show that the p47 of the NADPH oxidase, but not p65 or p40, physically binds to Nrf2, activating the Nrf2 function. p47 binding to Nrf2/Keap1 complex suppresses the ubiquitination of Nrf2, while p47 becomes ubiquitinated by Keap1. p47 increases the nuclear translocation of Nrf2 and the expression of Nrf2-dependent genes, whereas genetic ablation of p47 decreases the expression of those genes. In a lipopolysaccharide-induced acute lung inflammation mouse model, selective expression of p47 in mouse lungs induces the expression of Nrf2-dependent genes and is sufficient to suppress neutrophilic lung inflammation. Therefore, our findings suggest that p47 is a novel regulator of Nrf2 function.
Copyright © 2017 Elsevier Inc. All rights reserved.
0 Communities
1 Members
0 Resources
14 MeSH Terms
Chronicle of a Neuronal Death Foretold: Preventing Aging by Keeping MGRN1 at the Nucleus.
Ortolano NA, Gama V
(2017) Mol Cell 66: 301-303
MeSH Terms: Ubiquitin-Protein Ligases
Show Abstract · Added July 10, 2017
In this issue of Molecular Cell, Benvegnù et al. (2017) report an unexpected phenomenon by which the E3 ligase mahogunin ring finger-1 (MGRN1) translocates to the nucleus in an age-dependent manner, revealing an intriguing mechanism that allows for an adaptive neuronal response to proteotoxic stress, often seen with aging.
Copyright © 2017 Elsevier Inc. All rights reserved.
0 Communities
1 Members
0 Resources
1 MeSH Terms
Camptothecin resistance is determined by the regulation of topoisomerase I degradation mediated by ubiquitin proteasome pathway.
Ando K, Shah AK, Sachdev V, Kleinstiver BP, Taylor-Parker J, Welch MM, Hu Y, Salgia R, White FM, Parvin JD, Ozonoff A, Rameh LE, Joung JK, Bharti AK
(2017) Oncotarget 8: 43733-43751
MeSH Terms: BRCA1 Protein, Camptothecin, Cell Line, Tumor, DNA Topoisomerases, Type I, DNA-Binding Proteins, Drug Resistance, Neoplasm, Gene Editing, Humans, Ku Autoantigen, Multiprotein Complexes, PTEN Phosphohydrolase, Phosphorylation, Proteasome Endopeptidase Complex, Protein Binding, Protein Kinase C, Proteolysis, RNA Interference, Topoisomerase I Inhibitors, Ubiquitin
Show Abstract · Added November 26, 2018
Proteasomal degradation of topoisomerase I (topoI) is one of the most remarkable cellular phenomena observed in response to camptothecin (CPT). Importantly, the rate of topoI degradation is linked to CPT resistance. Formation of the topoI-DNA-CPT cleavable complex inhibits DNA re-ligation resulting in DNA-double strand break (DSB). The degradation of topoI marks the first step in the ubiquitin proteasome pathway (UPP) dependent DNA damage response (DDR). Here, we show that the Ku70/Ku80 heterodimer binds with topoI, and that the DNA-dependent protein kinase (DNA-PKcs) phosphorylates topoI on serine 10 (topoI-pS10), which is subsequently ubiquitinated by BRCA1. A higher basal level of topoI-pS10 ensures rapid topoI degradation leading to CPT resistance. Importantly, PTEN regulates DNA-PKcs kinase activity in this pathway and PTEN deletion ensures DNA-PKcs dependent higher topoI-pS10, rapid topoI degradation and CPT resistance.
0 Communities
1 Members
0 Resources
MeSH Terms