Date Thesis Awarded
Honors Thesis -- Open Access
Bachelors of Science (BS)
Shantá D. Hinton
The pseudophosphatase MK-STYX [MAPK (mitogen-activated protein kinase) phosphoserine/threonine/tyrosine binding protein] is a member of the MAP kinase phosphatase (MKP) family. Pseudophosphatases maintain their structure to bind phosphorylated residues, but cannot hydrolyze them; MK-STYX lacks the cysteine and histidine in what would be its catalytic signature motif (HCX5R). Despite the lack of catalytic activity, MK-STYX plays a role in many cellular signaling pathways such as stress response, apoptosis and neuronal development.
Therefore, we wanted to investigate MK-STYX in PC12 neuronal model and primary hippocampal neurons. We hypothesized that MK-STYX overexpression would alter dopamine localization, cytoskeletal protein localization, neuronal extensions and the morphology of primary neurons. The overexpression of MK-STYX increases neurite extension and branching in PC12 neuron-like cells in the presence of nerve growth factor (NGF).
Along with neurite extension and branching, MK-STYX also induces growth cones or actin projections in PC-12 at neurite terminals in the presence of NGF. MK-STYX overexpression also results a similar effect in hippocampal neurons. In our preliminary studies, MK-STYX seems to cause morphological changes when transfected into primary rat neurons. Future studies will focus on exploring the mechanisms behind these morphological changes in neurons. We will also investigate how MK-STYX affects a downstream effector of RhoA, cofilin. Overall, our data provides evidence that MK-STYX causes cytoskeleton rearrangements and validates that pseudophosphatases are important molecules in signal transduction.
Dahal, Arya, "Regulation of Neurite Outgrowths by the Pseudophosphatase MK-STYX in PC12 cells and Primary Neurons" (2017). Undergraduate Honors Theses. William & Mary. Paper 1041.