Neuroligins are members of a family of proteins known as cholinesterase-like adhesion molecules due to their structure similarity to an enzyme found in the nervous system, acetylcholinesterase. While Dr. Powell's lab will be examining the functional and biochemical consequences of mutations of this protein, the Sussman lab will use state of the art molecular biology techniques to determine if similar proteins such as gliotactin and neurotactin interacts with neuroligin, and what effects mutations of gliotactin and neurotactin produces on neuroligin expression. By studying proteins which interact with neuroligin, additional proteins whose mutation might be involved in autism or other neurodevelopmental diseases may be discovered. Significance: The protein neuroligin has been shown to be directly involved in synapse assembly in the central nervous system. The finding that mutations in this protein are associated with familial autism, Asperger syndrome and mental retardation supports the notion that development of the disease is associated with defective formation of neuronal connections or circuits. By examining the biophysical, biochemical and structural characterization the interaction of neuroligin with other proteins, these results may assist in the development of treatment approaches to autism by identifying possible molecular targets for therapeutics.