<p>Mutations in the gene SHANK2, which encodes a synaptic scaffolding protein, have been shown to cause a spectrum of neuropsychiatric disorders including: intellectual disability, autism spectrum disorders (ASDs), bipolar disorder (BD), and schizophrenia. However, many aspects of SHANK2 including the array of isoforms expressed, the expression pattern of the protein, biochemical and regulatory mechanisms, and in vivo protein function remain elusive. This body of work aims to uncover the function of the SHANK2 gene and its role in neuropsychiatric disorders using in vitro and in vivo experimental systems.</p> <p>Using a molecular genetics approach, I revealed the transcript architecture of the mouse Shank2 gene including characterization of promoters, isoforms and protein domains. I then outlined the temporal and spatial pattern of the Shank2 isoform expression throughout development. To further explore the protein’s function, we sought to identify novel SHANK2 interacting proteins using a yeast-2-hybrid screen and characterized the interacting proteins. Lastly, in order to understand how Shank2 deficiencies alter brain function we generated and characterized both Shank2 conventional (∆e24) and conditional mutant mice (e24floxed) by deleting or floxing exon 24 that encodes the Homer binding site and has nonsense mutations in human patients with neuropsychiatric disorders.</p> <p>Collectively, these studies 1) provide insight into the transcriptional regulation of Shank2 during brain development; 2) support the value of using Shank2 to further dissect the pathophysiology and circuitry mechanism underlying manic and autism like behaviors; 3) offers a novel mechanistic link between ubiquitination-mediated protein modification and SHANK2 function that may elucidate the molecular basis underlying SHANK2-related neuropsychiatric disorders. Ultimately, these findings may lead to the development of new therapeutic interventions for SHANK2-related neuropsychiatric disorders.</p> / Dissertation