Browsing by Author "Peck, Cameron"

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    Toward understanding the structure of Amot’s ACCH Domain
    (Office of the Vice Chancellor for Research, 2016-04-08) Peck, Cameron; Hurley, Thomas D.; Wells, Clark D.; Kimble-Hill, Ann C.
    Amots are a family of adaptor proteins widely involved in cell signaling and lipid binding. Amot80 has been linked to cellular proliferation in breast cancer via the VEGF and MAPK signaling pathways, while Amot130 and AmotL1 have been linked to cellular inhibition via the HIPPO signaling pathway. Amot family members also have a characteristic lipid-binding domain – named the ACCH Domain for its predicted coil-coil structure – that has the ability to selectively target phosphoinositols followed by deformation of the membrane. Understanding the structure-function relationship of this domain may provide options to modulate these signaling pathways, directly affecting cellular differentiation, proliferation, and migration. Extensive crystallization attempts for this domain have failed, leading to a bioinformatics and biophysics-combined approach. Using SAXS, data for the globular structure of Amot80 has been generated and analyzed. Additionally, the threading programs ITASSER and LOMETS were used to develop 20 computational theoretical models. By fitting the computational models to the SAXS data, potential ACCH domain models were generated, and then scored based on accuracy of fit via C-score, TMScore, and RMSD values. This 3D model can then be used to discover how Amot interacts with lipids and further the understanding of Amot’s role in the cancer-signaling cascade.
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    Using the Predicted Structure of the Amot Coiled Coil Homology Domain to Understand Lipid Binding
    (Indiana University, 2018) Peck, Cameron; Virtanen, Piia; Johnson, Derrick; Kimble-Hill, Ann C.; Biochemistry and Molecular Biology, School of Medicine
    Angiomotins (Amots) are a family of adapter proteins that modulate cellular polarity, differentiation, proliferation, and migration. Amot family members have a characteristic lipid-binding domain, the coiled coil homology (ACCH) domain that selectively targets the protein to membranes, which has been directly linked to its regulatory role in the cell. Several spot blot assays were used to validate the regions of the domain that participate in its membrane association, deformation, and vesicle fusion activity, which indicated the need for a structure to define the mechanism. Therefore, we sought to understand the structure-function relationship of this domain in order to find ways to modulate these signaling pathways. After many failed attempts to crystallize the ACCH domain of each Amot family member for structural analysis, we decided to pursue homologous models that could be refined using small angle x-ray scattering data. Theoretical models were produced using the homology software SWISS-MODEL and threading software I-TASSER and LOMETS, followed by comparison to SAXS data for model selection and refinement. We present a theoretical model of the domain that is driven by alpha helices and short random coil regions. These alpha helical regions form a classic dimer interface followed by two wide spread legs that we predict to be the lipid binding interface.