Heterotrimeric G-proteins : new analytical tools and identification of novel signaling components
- Gookin, Tim
- [University Park, Pennsylvania] : Pennsylvania State University, 2015.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Assmann, Sarah M.
- etda.libraries.psu.edu , Connect to this object online.
- Restrictions on Access:
- Open Access.
- Heterotrimeric G-protein signaling is one of the most important mechanisms eukaryotic organisms use to sense their environment, and as such, it is one of the most studied molecular signaling systems in eukaryotic biology. In humans, the intracellular heterotrimeric G-protein complexes play critical roles in our sense of sight, taste, smell, emotion,and central physiology by receiving extracellular signals perceived and transduced by plasma-membrane localized seven transmembrane G-protein coupled receptors (GPCRs). These numerous and diverse physiological processes are facilitated by > 800 predicted and known GPCRs in humans which signal to a large number of G-protein compexes with a theoretical combinatorial complexity of over 900 configurations. Similar to metazoan organisms, plants also sense and respond to their environment and it is abundantly clear that plants propagate a numerous and diverse set of signals through the hetrotrimeric G-protein complex. But in plants the number of known G-protein complex subunits is greatly reduced. There are no confirmed GPCRs, and prior to finishing this dissertation, the number of Arabidopsis G-protein complex configurations was limited to three. The question remains as to how the relatively sparse repertoire of plant G-proteins can be responsible for the wide range of physiological processes affected by G-protein subunit mutation. In this work: 1) I detail the bioinformatic identification and empirical validation of new candidate GPCRs, 2) develop and improve the Bimolecular Fluorescence Complementation methodology for in-planta protein-protein interaction, 3) use this new methodology in conjunction with other experimental methods to show the actual number of plant G-protein subunits is greater than previously thought, and 4) characterize two homologous candidate GPCRs. While it appears certain the two proteins analyzed are not plant G[alpha]-coupling GPCRs, they do play critical role in maintaining metabolic homeostasis; double mutants exhibit developmental stage-specific catastrophic leaf death in response to short photoperiod.
- Other Subject(s):
- Dissertation Note:
- Ph.D. Pennsylvania State University, 2015.
- Reproduction Note:
- Microfilm (positive). 1 reel ; 35 mm. (University Microfilms 10-609570)
- Technical Details:
- The full text of the dissertation is available as an Adobe Acrobat .pdf file ; Adobe Acrobat Reader required to view the file.
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