Role of Heterotrimeric G Proteins in Cilia Assembly and Pathogenesis of Neurodevelopmental Disorders
Neurodevelopmental
disorders (NDDs) in children comprise a range of conditions that include autism
spectrum disorders, developmental delay, intellectual disability, and
attention-deficit/hyperactivity disorder (ADHD). Our project is focused on the
gene called GNAI1. Mutations in this gene cause a severe NDD associated
with developmental delay, seizures, and autistic features. At this time, it
remains unknown why or how GNAI1 mutations disrupt normal
neurodevelopmental processes resulting in disease. Therefore, there is an
urgent need to define the role of GNAI1 in development of the nervous
system and determine how patient mutations interfere with this gene’s normal
cellular functions leading to NDD. Without this knowledge, discovery of
therapeutic interventions to improve NDD patients’ quality of life would be
hindered.
We
have discovered that the GNAI1 gene is critical for building primary
cilia – sensory structures that are present on the surface of all nerve cells
and that function akin to cellular antennae detecting and transmitting signals
from cells’ environment. The proper function of these structures is absolutely
essential for normal development of the nervous system, and when disrupted,
leads to genetic disorders with neurodevelopmental features. Using cutting-edge
genome engineering and microscopy tools in a genetically tractable experimental
model, we seek to determine how GNAI1 regulates assembly of primary
cilia and to build a genetic pipeline for rapid functional classification of a
growing number of GNAI1 variants from NDD patients. This work is
relevant to child health because it will foster a better understanding of the GNAI1
NDD etiology and facilitate the search for effective therapeutic targets to
manage NDD symptoms and thereby improve well-being of individuals living with
these conditions.