Show simple item record

dc.contributor.advisorTester, Mark A.
dc.contributor.authorAl-Younis, Inas
dc.date.accessioned2018-05-17T10:58:44Z
dc.date.available2019-05-16T00:00:00Z
dc.date.issued2018-05
dc.identifier.citationAl-Younis, I. (2018). Identification and Characterization of Novel Plant Adenylate Cyclases – The Arabidopsis Thaliana Potassium Uptake Permeases. KAUST Research Repository. https://doi.org/10.25781/KAUST-33QGX
dc.identifier.doi10.25781/KAUST-33QGX
dc.identifier.urihttp://hdl.handle.net/10754/627913
dc.description.abstractAdenylyl Cyclases (ACs) catalyze the formation of the key universal second messenger adenosine 3’, 5’-cyclic monophosphate (cAMP) from adenosine 5’- triphosphate. Cyclic AMP participates in several signal transduction pathways and is present in bacteria and higher and lower eukaryotes including higher plants. Previous studies in plants have shown a role for cAMP in signal transduction during e.g. the cell cycle, elongation of the pollen tube and stimulation of protein kinase activity. More recently cAMP has been shown to play a role in stress responses. Interestingly, cAMP has also been shown to regulate ion transport in plant cells. Here we used a similar strategy that led to the discovery of the first guanylyl cyclase in plants that was based on the alignment of conserved and functionally assigned amino acids in the catalytic centre of annotated nucleotide cyclases from lower and higher eukaryotes, to identify a novel candidate ACs in Arabidopsis (Arabidopsis thaliana K+ Uptake 5 and 7). ATKUP5 and 7 are homologous to K+ uptake permeases (KUPs) from bacteria and high-affinity K+ transporters (HAKs) from fungi. The AC activity was investigated by recombinantly expressing the ATKUP5 and 7 AC domain in vitro and by complementation of an E. coli AC mutant (cyaA). Furthermore, ATKUP5 was tested for its ability to functionally complement a yeast mutant deficient in Trk1 and Trk2 high affinity potassium uptake transporters. Site-mutagenesis in the AC domain was used to test the effect of both functions in each other. Furthermore, ATKUP5 was characterized electrophysiologically in HEK-293 cells to characterize the nature of this transporter. The localization of the ATKUP5 in Arabidopsis was examined using a Green Fluorescent Protein (GFP) fusion with the ATKUP5 to determine whether ATKUP5 is expressed at the plasma or tonoplast membrane. Arabiodpsis thaliana of the wild type, overexpressing ATKUP5 and atkup5 mutant lines were used to examine phenotypic differences.
dc.language.isoen
dc.subjectAdenylyl Cyclase
dc.subjectArabidopsis Thaliana
dc.subjectATKUP5
dc.subjectpotassium transporter
dc.subjectsignal transduction
dc.subjectcAMP
dc.titleIdentification and Characterization of Novel Plant Adenylate Cyclases – The Arabidopsis Thaliana Potassium Uptake Permeases
dc.typeDissertation
dc.contributor.departmentBiological and Environmental Science and Engineering (BESE) Division
dc.rights.embargodate2019-05-16
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberGehring, Christoph A
dc.contributor.committeememberMagistretti, Pierre J.
dc.contributor.committeememberVoolstra, Christian R.
dc.contributor.committeememberIrving, Helen
thesis.degree.disciplineBioscience
thesis.degree.nameDoctor of Philosophy
dc.rights.accessrightsAt the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation became available to the public after the expiration of the embargo on 2019-05-16.
refterms.dateFOA2019-05-16T00:00:00Z


Files in this item

Thumbnail
Name:
INAS'S Dissertation_Final.pdf
Size:
85.87Mb
Format:
PDF
Description:
INAS'S Dissertation_Final

This item appears in the following Collection(s)

Show simple item record