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- All Subjects: Calcium
- Creators: Gipson-Reichardt, Cassandra
- Creators: Marshall, Pamela
Description
Calcium is the only ion capable of triggering electrical and chemical reactions in cells which are part of essential biomolecular processes, such as gene transcription and ion flux. Calcium homeostasis, the control of concentration levels, is therefore crucial for the proper functioning of cells. For example, cardiomyocytes, the cells that form cardiac muscle, rely on calcium transfer process to produce muscle contraction.
The purpose of this work is to study aspects of calcium homeostasis in the model organism Saccharomyces cerevisiae, common yeast. Using luminometric techniques, the response of the yeast was monitored against a set of changes in the environment calcium abundance. The results indicate a complex response as both increase and decreases of external calcium induce elevations in cytosolic calcium concentrations.
Calcium is transferred across compartments by means of channels. In Saccharomyces cerevisiae, many of them have been identified; Cch1p-Mid1p, Vcx1p, Pmc1p, Pmr1p, and Yvc1p. Their participation in calcium homeostasis is well established. Observations of cytosolic calcium increase after a hypertonic shock are mainly associated with influx of ions from the environment though the Cch1p-Mid1p. This process is generally considered as driven by calcium concentration gradients. However, recent studies have suggested that the plasma membrane channel, Cch1p-Mid1p, may possess more sophisticated regulation and sensory mechanisms. The results of our experiments support these ideas.
We carried out experiments that subjected yeast to multiple shocks: a hypertonic shock followed by either a second hypertonic shock, a hypotonic shock, or a yeast dilution pulse where the solution volume increases by the calcium concentration has only a small change. The cytosolic calcium concentration of a yeast population was monitored via luminometry.
The main result of this study is the observation of an unexpected response to the combination of hypertonic and hypotonic shocks. In this case it was observed that the cytosolic calcium concentration increased after both shocks. This indicates that cytosolic calcium increases are not solely driven by the presence of concentration gradients. The response after the hypotonic pulse arises from more complex mechanisms that may include sensor activity at the membrane channels and the release of calcium from internal storages.
The purpose of this work is to study aspects of calcium homeostasis in the model organism Saccharomyces cerevisiae, common yeast. Using luminometric techniques, the response of the yeast was monitored against a set of changes in the environment calcium abundance. The results indicate a complex response as both increase and decreases of external calcium induce elevations in cytosolic calcium concentrations.
Calcium is transferred across compartments by means of channels. In Saccharomyces cerevisiae, many of them have been identified; Cch1p-Mid1p, Vcx1p, Pmc1p, Pmr1p, and Yvc1p. Their participation in calcium homeostasis is well established. Observations of cytosolic calcium increase after a hypertonic shock are mainly associated with influx of ions from the environment though the Cch1p-Mid1p. This process is generally considered as driven by calcium concentration gradients. However, recent studies have suggested that the plasma membrane channel, Cch1p-Mid1p, may possess more sophisticated regulation and sensory mechanisms. The results of our experiments support these ideas.
We carried out experiments that subjected yeast to multiple shocks: a hypertonic shock followed by either a second hypertonic shock, a hypotonic shock, or a yeast dilution pulse where the solution volume increases by the calcium concentration has only a small change. The cytosolic calcium concentration of a yeast population was monitored via luminometry.
The main result of this study is the observation of an unexpected response to the combination of hypertonic and hypotonic shocks. In this case it was observed that the cytosolic calcium concentration increased after both shocks. This indicates that cytosolic calcium increases are not solely driven by the presence of concentration gradients. The response after the hypotonic pulse arises from more complex mechanisms that may include sensor activity at the membrane channels and the release of calcium from internal storages.
ContributorsMintz, David Anthony (Co-author) / Parker, Augustus (Co-author) / Solis, Francisco (Thesis director) / Marshall, Pamela (Committee member) / School of Mathematical and Natural Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Adolescent mental health problems are predicative of future problems such as depression, anxiety, ADHD, compulsive disorder, and substance use. Previous studies show that in emerging adulthood, the high prevalence and associated burdens of psychopathology increase vulnerability to disorders. These diagnoses are less common but are more severe and chronic (Tanner et al., 2009). The causes of these disorders are still being explored with recent studies showing that these mental health problems are genetically influenced. This makes understanding which gene that corresponds to what biological system is important in determining mental health. From recent studies, genes that code for calcium channels are good candidates for mental health problems. These voltage-gated channels are important mediators for physiological functions in the central nervous system and their activation provides unique responses within the brain. In a previous study, it supports the association of polymorphisms in calcium and potassium channels with the genetic risk for bipolar disorders and other mental illness (Imbrici et al., 2013). The purpose of the study was to examine if calcium channel genes influence childhood psychiatric symptoms. The first goal of this study was to form a polygenic risk score representing genetic influence on calcium channels. The second goal was to use this risk score in genetic association analyses to understand genetic risk for childhood psychopathology. Overall, the study did accomplish the goal as a polygenic risk score was created and was used to examine genetic association with child psychopathology. Based on the results, the polygenic risk score was not correlated with either parent or child- reported symptoms; however, results did show that disorders were related to each other and differed by race.
ContributorsTang, Derek (Author) / Lemery, Kathryn (Thesis director) / Gipson-Reichardt, Cassandra (Committee member) / Elam, Kit (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05