Copy number variants (CNVs) and de novo mutations represent significant risk factors for Autism SpectrumDisorders (ASD). One of the most frequent CNVs involved in ASD is a deletion or duplication of the16p11.2CNV locus, spanning 29 protein-coding genes. Despite the progress in linking 16p11.2 genetic changes withthe phenotypic (macrocephaly and microcephaly) abnormalities in the patients and model organisms, thespecific molecular pathways impacted by this CNV remain unknown. In our recent study we demonstrated thatKCTD13, a gene within the 16p11.2 locus, is co-expressed and physically interacts with Cul3 ubiquitin ligaseprimarily during late mid-fetal cortical brain development. This interaction may be crucial for regulating thelevels of a small GTPase RhoA, a major regulator of actin cytoskeleton and cell migration. Based on theseresults, we propose the hypothesis that functional impact of the 16p11.2 CNV is manifested throughdysregulation of the RhoA and downstream signaling pathways including neuronal migration, cytoskeletaldynamics, proliferation and apoptosis. We will test this hypothesis using existing 16p11.2 (Horev, 2011;Portmann, 2014) and developing new KCTD13 and Cul3 mouse models with CRISPR/Cas9 technology. Toinvestigate cellular and molecular pathways impacted by the 16p11.2 CNV, we will apply integrative functionalgenomics approaches including genome-wide transcriptomic and proteomic profiling of the embryonic andearly postnatal brain tissues. The goal of this project is to develop better understanding of the relationshipsbetween brain size and the 16p11.2 deletion/duplication genotypes, and to determine the detailed cellular andmolecular mechanisms responsible for brain size differences. We will achieve this goal through the followingSpecific Aims: (1) Generate KCTD13 and CUL3 mouse models using CRISPR/Cas9 system and characterizecellular phenotypes in the developing brain; (2) Investigate molecular impact of the 16p11.2 CNV, KCTD13 andCUL3 mutations to identify dysregulated pathways; (3) Characterize behavioral phenotypes of the developedmouse models and test pharmacological inhibitors for phenotype reversal. This project will address animportant but yet unresolved question regarding cellular and molecular pathways disrupted by the mostfrequent CNV implicated in multiple neurodevelopmental disorders. These pathways may represent highpriority targets for future therapeutic interventions in ASD.
Interagency Autism Coordinating Committee (IACC)
Autism Research Database (AFD)
