Life Sciences Commons^™

Recombinant Netrin-4 Does Not Signal Through The Netrin-1 Or Netrin-3 Pathway In Tetrahymena Thermophila, Nicholas Bradley, Heather G. Kuruvilla

The Research and Scholarship Symposium (2013-2019)

Netrin 4 protein and its homologs are found throughout the animal kingdom. Netrin-4 is known to have a protective role against vascular damage. Previous studies have shown that human netrin-1 has a role in angiogenesis. This information about human netrin-1 and netrin-4 led us to research the pathway of netrin-4 in Tetrahymena thermophila. Our previous studies of the netrin proteins show that netrin-1 and netrin-3 are both repellents in Tetrahymena thermophila. The data in this study show that netrin-4 is also a repellent of Tetrahymena thermophila. These data suggest that netrin-4 could signal through the same pathway as netrin-1 and …

Tetrahymena Thermophila Lack A Homologue Of The Caenorhabditis Elegans Lin-4 Mirna, Bryce H. Childers, Sorrel Paris, Emma Wessels, Heather G. Kuruvilla

The Research and Scholarship Symposium (2013-2019)

The netrin family of proteins was first discovered because of their role in axonal guidance during development. Netrin homologues are important developmental signals in organisms ranging from vertebrates to the nematode, Caenorhabditis elegans, and netrin-like proteins have even been found in the ciliated protozoan, Tetrahymena thermophila. Since the lin-4 miRNA regulates netrin signaling in C. elegans, we hypothesized that a lin-4 homologue might exists in Tetrahymena thermophila. In order to test this hypothesis, we purified total miRNA from T. thermophila, used this miRNA to make cDNA, then used RT-PCR to quantitate the amount of lin-4 specific cDNA we obtained. Our …

Mapping Netrin Signaling In Tetrahymena Thermophila, Katelyn R. Malik, Bethany C. Khol, Stephanie J. Hermann, Kenneth W. Ward, Daniele T. Modderman, Heather G. Kuruvilla

The Research and Scholarship Symposium (2013-2019)

The netrin family of proteins, found throughout the animal kingdom, are well known for their roles in developmental signaling. Netrin-1, the best-studied member of this family, signals through four receptor types in vertebrates: the UNC-5 family, DCC, neogenin, and DSCAM. We have previously characterized a netrin-1-like protein in the ciliated protozoan, Tetrahymena thermophila. This protein is secreted from Tetrahymena, and functions as a chemorepellent. Since a netrin-like protein is produced by this organism, we hypothesized that some components of the vertebrate netrin signaling pathway might also be present in Tetrahymena. Through immunolocalization on the plasma membrane of the cell, we …

Netrin-3: Tracking The Elusive Antimitotic Signal On The Western Frontier, Michael David Jolley, Kirsten P. Kelley, Jared E. Matz, Natalie S. Phillips, Emma Wessels, Heather G. Kuruvilla

The Research and Scholarship Symposium (2013-2019)

Netrin-3 is a guidance protein expressed throughout the animal kingdom, and involved in the development of branched structures such as the nervous system, lung, and mammary gland. We have previously shown that peptides derived from this protein serve as chemorepellents and mitotic inhibitors in Tetrahymena thermophila. Our previous work shows that Tetrahymena synthesize and secrete a netrin-3-like protein, as detected by ELISA. In this study, we find that a netrin-3-like protein is present in whole cell extract and secreted protein, as detected by Western blotting. A protein of approximately 48 kD is consistently detected in our Western blots. In addition, …

Netrin-3 Signals Through Serine Phosphorylation In Tetrahymena Thermophila, Cayla C. Eckley, Rebecca N. Haught, Kyle J. Hooper, Jared E. Matz, Joshua L. Wilson, Bethany C. Khol, Katelyn R. Malik, Heather G. Kuruvilla

The Research and Scholarship Symposium (2013-2019)

The netrin family of proteins are structurally related to laminin and, while first discovered in the nematode Caenorhabditis elegans, are now known to be present in species throughout the animal kingdom, including humans. These proteins also have a wide variety of roles that include inhibition of apoptosis, chemorepulsion, and axonal guidance. Due to the results of previous studies involving netrin-1 in vertebrate systems, the current prevailing assumption is that netrins, when acting as chemorepellents, signal using tyrosine kinases. However, data that we gathered through phosphoserine-targeting ELISA assays and immunofluorescence microscopy demonstrates that the netrin-3 peptides signal Tetrahymena thermophila through serine …

Netrin-3 Peptide (C-19) Is A Chemorepellent And A Growth Inhibitor In Tetrahymena Thermophila, Jennifer N. Felzien, Brandon R. Kalb, Bethany C. Khol, Katelyn R. Malik, Matthew S. Merical, Lois Parks, David Paulding, Shannon Rappaport, Kenneth W. Ward, Heather G. Kuruvilla

The Research and Scholarship Symposium (2013-2019)

The netrins are a family of signaling proteins expressed throughout the animal kingdom. Netrins play important roles in developmental processes such as axonal guidance and angiogenesis. Netrin-1, for example, can act as either a chemoattractant or a chemorepellent for axonal growth cones depending upon the concentration of the protein as well as the cell type. Netrin-1 acts as a growth factor in some mammalian cell types and is also expressed by some tumor cells. Netrin-3 appears to share some signaling apparatus with netrin-1, but is less widely expressed, and its physiological roles are much less understood. Netrin-3 is also used …

Netrin-1 Signals Through Protein Kinases In Tetrahymena Thermophila, Bethany C. Khol, Katelyn R. Malik, Heather G. Kuruvilla

The Research and Scholarship Symposium (2013-2019)

Netrins are a family of signaling proteins involved in developmental processes such as neuronal guidance and angiogenesis. The best characterized netrin, netrin-1, signals through a number of different receptors. When acting as a chemoattractant, netrin-1 primarily signals through the DCC receptor and associated protein tyrosine kinase and MAP kinase signaling pathways. When acting as a chemorepellent, netrin-1 signals through the UNC5 receptor, which involves recruitment of the protein tyrosine phosphatase, SHP2.

While netrins are ubiquitously expressed throughout the animal kingdom, our laboratory was the first to describe a netrin-1 like protein in Tetrahymena. This netrin-1 like protein is secreted …

Netrin-3 Avoidance And Mitotic Inhibition In Tetrahymena Thermophila Involves Intracellular Calcium And Serine/Threonine Kinase Activity, Stephanie J. Hermann, Bailey L. Hixon, Bethany C. Khol, Ryan D. Kvarness, Jade Lee, Katelyn R. Malik, Gregg W. Mendel, Daniele T. Modderman, Lois Parks, David Paulding, Kenneth W. Ward, Matthew A. Sitler, Heather G. Kuruvilla

The Research and Scholarship Symposium (2013-2019)

Netrins are a family of signaling proteins ubiquitously expressed throughout the animal kingdom. While netrin-1 has been well characterized, other netrins, such as netrin-3, remain less well understood. In our current study, we characterize the behavior of two netrin-3 peptides, one derived from the N-terminal and one derived from the C-terminal of netrin-3. Both peptides cause avoidance behavior and mitotic inhibition in Tetrahymena thermophila at concentrations as low as 0.5 micrograms (μg) per milliliter. These effects can be reversed by addition of the calcium chelator, EGTA; the intracellular calcium chelator, BAPTA-AM, or the serine/threonine kinase inhibitor, apigenin. The broad spectrum …