Characterization of Proteins Interacting with the Alpha Subunit of Actin Capping Protein
Location
CSU North Ballroom
Start Date
24-4-2006 1:30 PM
End Date
24-4-2006 3:30 PM
Student's Major
Biological Sciences
Student's College
Science, Engineering and Technology
Mentor's Name
Marilyn Hart
Mentor's Department
Biological Sciences
Mentor's College
Science, Engineering and Technology
Description
Actin, a filamentous component of all cells, contributes to cell shape, cell motility and force transmission. Actin assembly and dynamics are regulated by a diverse array of regulatory proteins, including actin capping protein (CP). CP is a heterodimeric protein composed of two subunits, alpha (a) and beta (P). Three isoforms of each subunit exist in eukaryotes. The p isoforms have been shown to have distinct functions in vivo. The functions of the specific a isoforms have yet to be determined. Overall, the amino acid sequence of the a isoforms are highly conserved, sharing approximately 90% sequence identity. The region of divergence is also highly conserved among higher organisms, suggesting that the alpha isoforms have distinct functions in vivo. We hypothesize that the alpha isoforms perform different functions in cells/tissues. The purpose of this research is to investigate the function of the alpha proteins of CP by identifying proteins that interact with the al and a2 subunits. In a previous yeast two hybrid genetic screen, potential interacting proteins were identified. Our goal is to characterize these proteins via plasmid sizing and sequence analysis. We have purified the plasmid DNA, transformed into competent E. coli, and plated onto selective media to isolate the plasmid of interest. The plasmid was purified and the insert amplified using Polymerase Chain Reaction (PCR). Duplicates were identified and the unique DNA fragments will be sent to the University of Minnesota Sequencing Center for subsequent analysis. THE EFFECTS OF TEMPERATURE ON THE COMPETITIVE INTERACTIONS OF Bromus inermis AND Andropogon gerardii Christopher D. Kniffen (Biological Sciences) Christopher T Ruhland, Faculty Mentor (Biological Sciences) Invasive species are widely recognized globally for reducing biological diversity and threatening endangered and rare species. Bromus inermis (Smooth Brome) was introduced into the United States in the late 1800s to help alleviate erosion. In the past several years B. inermis has expanded its range creating monocultures that reduce overall diversity in the remaining tall grass prairie. In this study, we focused on physiological mechanisms responsible for competitive interactions between the invasive B. inermis and Andropogon gerardii (Big Bluestem; a native grass) under two different temperature regimes. Plants were grown intra- and interspecifically at 20 and 25" C for ten weeks in pots placed in environmental chambers. We examined leaf photosynthesis, transpiration, stomatal conductance and internal CO2 concentrations using an infrared gas analyzer. We also measured xylem water potential using a Scholander pressure bomb. Interspecific competition resulted in large reductions in the biomass of B. inermis than when grown intraspecifically at both 20 and 25° C. Transpiration rates of B. inermis were 42 and 24% higher than those of A. gerardii at 20 and 25° C, respectively. In addition, leaf water potential of B. inermis was 49% more negative than A. gerardii. We suspect that the increased competitive ability of A. gerardii results from a greater water use efficiency than B. inermis (based upon transpiration, photosynthesis and stomatal conductance measurements). Our results suggest that future increases in air temperature may alter the competitive balance between these two species, however uncertainties regarding future changes in precipitation may overshadow these temperature effects.
Characterization of Proteins Interacting with the Alpha Subunit of Actin Capping Protein
CSU North Ballroom
Actin, a filamentous component of all cells, contributes to cell shape, cell motility and force transmission. Actin assembly and dynamics are regulated by a diverse array of regulatory proteins, including actin capping protein (CP). CP is a heterodimeric protein composed of two subunits, alpha (a) and beta (P). Three isoforms of each subunit exist in eukaryotes. The p isoforms have been shown to have distinct functions in vivo. The functions of the specific a isoforms have yet to be determined. Overall, the amino acid sequence of the a isoforms are highly conserved, sharing approximately 90% sequence identity. The region of divergence is also highly conserved among higher organisms, suggesting that the alpha isoforms have distinct functions in vivo. We hypothesize that the alpha isoforms perform different functions in cells/tissues. The purpose of this research is to investigate the function of the alpha proteins of CP by identifying proteins that interact with the al and a2 subunits. In a previous yeast two hybrid genetic screen, potential interacting proteins were identified. Our goal is to characterize these proteins via plasmid sizing and sequence analysis. We have purified the plasmid DNA, transformed into competent E. coli, and plated onto selective media to isolate the plasmid of interest. The plasmid was purified and the insert amplified using Polymerase Chain Reaction (PCR). Duplicates were identified and the unique DNA fragments will be sent to the University of Minnesota Sequencing Center for subsequent analysis. THE EFFECTS OF TEMPERATURE ON THE COMPETITIVE INTERACTIONS OF Bromus inermis AND Andropogon gerardii Christopher D. Kniffen (Biological Sciences) Christopher T Ruhland, Faculty Mentor (Biological Sciences) Invasive species are widely recognized globally for reducing biological diversity and threatening endangered and rare species. Bromus inermis (Smooth Brome) was introduced into the United States in the late 1800s to help alleviate erosion. In the past several years B. inermis has expanded its range creating monocultures that reduce overall diversity in the remaining tall grass prairie. In this study, we focused on physiological mechanisms responsible for competitive interactions between the invasive B. inermis and Andropogon gerardii (Big Bluestem; a native grass) under two different temperature regimes. Plants were grown intra- and interspecifically at 20 and 25" C for ten weeks in pots placed in environmental chambers. We examined leaf photosynthesis, transpiration, stomatal conductance and internal CO2 concentrations using an infrared gas analyzer. We also measured xylem water potential using a Scholander pressure bomb. Interspecific competition resulted in large reductions in the biomass of B. inermis than when grown intraspecifically at both 20 and 25° C. Transpiration rates of B. inermis were 42 and 24% higher than those of A. gerardii at 20 and 25° C, respectively. In addition, leaf water potential of B. inermis was 49% more negative than A. gerardii. We suspect that the increased competitive ability of A. gerardii results from a greater water use efficiency than B. inermis (based upon transpiration, photosynthesis and stomatal conductance measurements). Our results suggest that future increases in air temperature may alter the competitive balance between these two species, however uncertainties regarding future changes in precipitation may overshadow these temperature effects.
Recommended Citation
DuCharme, Angelique and Charity Zabel. "Characterization of Proteins Interacting with the Alpha Subunit of Actin Capping Protein." Undergraduate Research Symposium, Mankato, MN, April 24, 2006.
https://cornerstone.lib.mnsu.edu/urs/2006/poster-session-B/1
