Elizabeth Fidalgo da Silva

University of Windsor

Tuberin is a member of a large protein complex, Tuberous Sclerosis Complex (TSC), and acts as a sensor for nutrient status regulating protein synthesis and cell cycle progression. Mutations in the Tuberin gene, TSC2, permits the formation of tumors that can lead to developmental defects in many organ systems, including the central nervous system. T...

Tuberin is a major component of the protein regulatory complex known as the Tuberous Sclerosis Complex and plays a crucial role in cell cycle progression and protein synthesis. Mutations in the Tuberin gene, TSC2, lead to the formation of benign tumors in many organ systems and causes the Tuberous Sclerosis Complex disorder. Genotypes ranging from...

The ability of cells to sense diverse environmental signals, including nutrient availability and conditions of stress, is critical for both prokaryotes and eukaryotes to mount an appropriate physiological response. While there is a great deal known about the different biochemical pathways that can detect and relay information from the environment,...

Tuberin is a major component of the protein regulatory complex known as the Tuberous Sclerosis Complex and plays a crucial role in cell cycle progression and protein synthesis. Mutations in the Tuberin gene, TSC2, lead to the formation of benign tumors in many organ systems and causes the Tuberous Sclerosis Complex disorder. Genotypes ranging from...

Tuberin is a member of a large protein complex, Tuberous Sclerosis Complex, and acts as a sensor for nutrient status regulating protein synthesis and cell cycle progression. Mutations in the Tuberin gene, TSC2, lead to the formation of tumors and developmental defects in many organ systems, including the central nervous system. Tuberin is expressed...

Fully differentiated cells can be reprogrammed through ectopic expression of key transcription factors to create induced pluripotent stem cells. These cells share many characteristics of normal embryonic stem cells and have great promise in disease modelling and regenerative medicine. The process of remodelling has its limitations, including a very...

A great deal of ground breaking work has determined that the Tuberin and Hamartin Complex function as a negative regulator of protein synthesis and cell cycle progression through G1/S. This is largely attributed to the GTPase activity of Tuberin that indirectly inhibits the mammalian target of rapamycin (mTOR). During times of ample nutrition Tuber...

CycB1 is retained in the cytoplasm in an mTORC-independent manner during serum starvation. HEK293 cells transfected with CycB1-5xE-GFP were co-transfected with TSC2-WT or TSC2-SATA. 18 hrs following transfection, cells were washed with PBS and incubated for 2 hrs with 0.5% or 10% FBS, followed by the addition of either vehicle control or Rapamycin...

Morphological changes to SATA cells are not due cell death. HEK293 cells were transfected with Mock control, WT-TSC2 and TSC2-SATA. 18 hrs following transfection cell were washed with PBS, fresh medium with 10% FBS 1% P/S was added and cells were incubated at 37°C in 5% CO2 for 24 hrs. Cells were collected and the DNA was labelled with propidium io...

Ozone has been shown to be effective in the transformation of several chemicals of emerging concern that escape the wastewater treatment process, but there is concern whether toxic transformation products are formed. Two parallel biofilter columns with granular activated carbon (GAC) and filter sand following a pilot-scale ozone unit to treat secon...

Progression through G2 phase of the cell cycle is a technically difficult area of cell biology to study due to the lack of physical markers specific to this phase. The FUCCI system uses the biology of the cell cycle to drive fluorescence in select phases of the cell cycle. Similarly, a commercially available system has used a fluorescent analog of...

The heterogeneity of brain cancers, as most solid tumors, complicates diagnosis and treatment. Identifying and targeting populations of cells driving tumorigenesis is a top priority for the cancer biology field. This is not a trivial task; considerable variance exists in the driving mutations, identifying markers, and evolutionary pressures influen...

Tuberous sclerosis is a multi-organ disorder characterized by the formation of benign tumors, called hamartomas, which affects more than 1 million people worldwide. The syndrome is initiated by a mutation in one of two tumor suppressor genes, TSC1 or TSC2, that encode for the proteins hamartin and tuberin, respectively. Herein, we demonstrate that...

DNA polymerases achieve high-fidelity DNA replication in part by checking the accuracy of each nucleotide that is incorporated and, if a mistake is made, the incorrect nucleotide is removed before further primer extension takes place. In order to proofread, the primer-end must be separated from the template strand and transferred from the polymeras...

Proofreading DNA polymerases share common short peptide motifs that bind Mg(2+) in the exonuclease active center; however, hydrolysis rates are not the same for all of the enzymes, which indicates that there are functional and likely structural differences outside of the conserved residues. Since structural information is available for only a few p...

Calmodulin (CaM) and troponin C (TnC) are EF-hand proteins that play fundamentally different roles in animal physiology. TnC has a very low affinity for the plasma membrane Ca2+-ATPase and is a poor substitute for CaM in increasing the enzyme's affinity for Ca2+ and the rate of ATP hydrolysis. We use a series of recombinant TnC (rTnC)/CaM chimeras...

The ability of wild type and mutant T4 DNA polymerases to discriminate in the utilization of the base analog 2-aminopurine (2AP) and the fluorescence of 2AP were used to determine how DNA polymerases distinguish between correct and incorrect nucleotides. Because T4 DNA polymerase incorporates dTMP opposite 2AP under single-turnover conditions, it w...

Calmodulin (CaM) and troponin C (TnC) are the most similar members of EF-hand family and show few differences in the primary structure. Here, we use mutants of troponin that mimic calmodulin and changes in temperature to investigate the factors that determine their specificity as regulatory proteins. Using a double mutant of troponin that resembles...

The fluorescence of the base analogue 2-aminopurine (2AP) was used to detect physical changes in the template strand during nucleotide incorporation by the bacteriophage T4 DNA polymerase. Fluorescent enzyme-DNA complexes were formed with 2AP placed in the template strand opposite the primer terminus (the n position) and placed one template positio...

DNA replication normally occurs with high fidelity, but certain "slippery" regions of DNA with tracts of mono-, di-, and trinucleotide repeats are frequently mutation hot spots. We have developed an in vitro assay to study the mechanism of dinucleotide repeat expansion. The primer-template resembles a base excision repair substrate with a single nu...

To assess the structural and functional significance of the N helix (residues 3-13) of avian recombinant troponin C (rTnC), we have constructed NHdel, in which residues 1-11 have been deleted, both in rTnC and in the spectral probe mutant F29W (Pearlstone, J. R., Borgford, T., Chandra, M., Oikawa, K., Kay, C. M., Herzberg, O., Moult, J., Herklotz,...

Troponin C can replace calmodulin in the activation of the Ca(2+)-ATPase of pig erythrocytes provided that the reaction medium contains relatively high free Ca2+ concentrations (> 0.5 microM). In the presence of 10 microM free Ca2+, the troponin C-activated ATPase reaches a maximal velocity of approximately 70% of that attained with calmodulin. The...