This gene encodes a protein belonging to the guanine nucleotide exchange factor family, and which regulates the configuration of cell junctions. It contains multiple binding sites for dynamin and thus links dynamin to actin regulatory proteins. Polymorphisms in this gene have been linked to Alzheimer's disease in some populations, though there are conflicting reports of such linkages in other populations. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2015].