Andrew D. L. Nelson - Postdoctoral Research Associate
I received my Ph.D. in the lab of Dorothy Shippen in the Biochemistry and Biophysics department at Texas A&M University.
I am interested in the evolution of the telomerase RNA in plants, and particularly the family Brassicaceae, which harbors the model plant, Arabidopsis thaliana. The recent identification of the telomerase RNA subunit, TER, in Arabidopsis led to the search for TERs in other closely related Brassicaceae members. Surprisingly, many Arabidopsis relatives, including A. lyrata, do not encode a canonical TER at the same locus as the AtTER1 (Beilstein et al, 2012). This is particularly interesting, because other RNA-binding telomerase components, such as TERT and POT1a, do not exhibit such dramatic variation. What are the other telomerase RNAs in Brassicaceae, and how are they structurally adapting to the binding requirements of the telomerase components?
I am also interested in the presence of non-coding RNAs (ncRNAs) in integral pathways such as DNA damage and telomerase regulation. Contrary to the central dogma, a large percentage of eukaryotic genomes are transcribed, but these RNAs do not encode for proteins. Instead, they regulate almost every molecular pathway in the cell. While the importance of small RNAs is well-established, the functional significance of larger ncRNAs is not quite as clear. A perfect example of a large ncRNA is TER. TER functions as a template for the reverse transcriptase, TERT, to add telomeres to the chromosome end. TER also serves as a scaffold for multiple accessory proteins to bind and affect how the telomerase holoenzyme mediates its functions. In Arabidopsis, and potentially other plant species, there are multiple TERs, and only one (AtTER1) is the canonical TER (Cifuentes-Rojas et al, 2011). AtTER2 binds to a completely different set of accessory proteins and acts to inhibit telomerase activity during DNA damage events (and potentially at other points in the cell cycle; Cifuentes-Rojas et al, 2012). One interesting accessory protein of the TER2 complex is the heterodimer Ku, which is also important for double strand DNA repair and telomere protection. I would like to determine if Ku associates with telomerase RNAs (both canonical and non-canonical) in other plant species. A Ku-TER connection is found in both yeast and vertebrates, suggesting this interaction may be broadly conserved. I would like to understand the functional significance of this interaction.
For a list of my recent publications, click here.
You can contact me at [email protected]
Outside of science, my wife and I particularly like bicycling and hiking with in the Tucson area. Mount Lemmon serves as a beautiful backdrop for both of these activities. On a bike, Mount Lemmon climbs ~6500 feet over the course of ~27 (well-paved) miles, making it an excellent challenge for someone completely new to mountain climbing. There are numerous trails to hike and beautiful vistas to view the surrounding area from. Tucson also has a large variety of really good places to eat (and hence my other favorite thing to do here).
I am interested in the evolution of the telomerase RNA in plants, and particularly the family Brassicaceae, which harbors the model plant, Arabidopsis thaliana. The recent identification of the telomerase RNA subunit, TER, in Arabidopsis led to the search for TERs in other closely related Brassicaceae members. Surprisingly, many Arabidopsis relatives, including A. lyrata, do not encode a canonical TER at the same locus as the AtTER1 (Beilstein et al, 2012). This is particularly interesting, because other RNA-binding telomerase components, such as TERT and POT1a, do not exhibit such dramatic variation. What are the other telomerase RNAs in Brassicaceae, and how are they structurally adapting to the binding requirements of the telomerase components?
I am also interested in the presence of non-coding RNAs (ncRNAs) in integral pathways such as DNA damage and telomerase regulation. Contrary to the central dogma, a large percentage of eukaryotic genomes are transcribed, but these RNAs do not encode for proteins. Instead, they regulate almost every molecular pathway in the cell. While the importance of small RNAs is well-established, the functional significance of larger ncRNAs is not quite as clear. A perfect example of a large ncRNA is TER. TER functions as a template for the reverse transcriptase, TERT, to add telomeres to the chromosome end. TER also serves as a scaffold for multiple accessory proteins to bind and affect how the telomerase holoenzyme mediates its functions. In Arabidopsis, and potentially other plant species, there are multiple TERs, and only one (AtTER1) is the canonical TER (Cifuentes-Rojas et al, 2011). AtTER2 binds to a completely different set of accessory proteins and acts to inhibit telomerase activity during DNA damage events (and potentially at other points in the cell cycle; Cifuentes-Rojas et al, 2012). One interesting accessory protein of the TER2 complex is the heterodimer Ku, which is also important for double strand DNA repair and telomere protection. I would like to determine if Ku associates with telomerase RNAs (both canonical and non-canonical) in other plant species. A Ku-TER connection is found in both yeast and vertebrates, suggesting this interaction may be broadly conserved. I would like to understand the functional significance of this interaction.
For a list of my recent publications, click here.
You can contact me at [email protected]
Outside of science, my wife and I particularly like bicycling and hiking with in the Tucson area. Mount Lemmon serves as a beautiful backdrop for both of these activities. On a bike, Mount Lemmon climbs ~6500 feet over the course of ~27 (well-paved) miles, making it an excellent challenge for someone completely new to mountain climbing. There are numerous trails to hike and beautiful vistas to view the surrounding area from. Tucson also has a large variety of really good places to eat (and hence my other favorite thing to do here).