Poster abstracts
Poster number 32 submitted by Lily Schumacher
Characterizing structural differences between plant KASH proteins and determining their functional contributions
Lily Schumacher (Biophysics Program, The Ohio State University), Norman R. Groves (Department of Molecular Genetics, The Ohio State University), Iris Meier (Department of Molecular Genetics, The Ohio State University)
Abstract:
Nuclear movement and positioning are commonly associated with cellular development and environmental responses in animals, fungi, and plants. The ability of these organisms to move their nuclei is force dependent and mediated by a protein complex that spans the nuclear envelope, known as the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex. The LINC complex is made up of inner nuclear membrane Sad1/UNC-84 (SUN) proteins and outer nuclear membrane Klarsicht/ANC-1/Syne Homology (KASH) proteins. KASH proteins interact with SUN proteins via a 9-30 amino acid C-terminal KASH domain. Animal KASH domains have specific structural requirements to enable different cellular functions and force transfer, whereas the different structural requirements of plant KASH (pKASH) domains have not been investigated. KASH protein structure differs across plant species, yet the species-specific requirements of plant KASH proteins have not been determined. Investigating the importance of specific domains involved in force transfer, as well as differences in LINC complexes across plant species, can elucidate how the structure of the LINC complex imparts function.
Here, I utilize two known plant KASH proteins (SINE1 and WIP1) and their associated mutant phenotypes in root nuclear shape, pollen tube migration order, and stomatal closure to characterize the structural importance of different pKASH domains and proteins. First, I am testing whether chimeric Arabidopsis KASH proteins with swapped pKASH domains can restore wildtype KASH protein function. Second, I have generated Arabidopsis transgenic lines that replace Arabidopsis KASH proteins with homologous Medicago truncatula KASH proteins and will assess their ability to function in this heterologous context. Together, these data will address functional diversification of the plant-specific KASH-SUN interaction within and between higher plant species.
Keywords: LINC Complex, Nucleus, Nuclear Envelope