Contributes to guanyl-nucleotide exchange factor activity. Involved in several processes, including nervous system development; response to glucose; and response to heat. Located in axon. Part of eukaryotic translation initiation factor 2B complex. Human ortholog(s) of this gene implicated in leukoencephalopathy with vanishing white matter. Orthologous to human EIF2B2 (eukaryotic translation initiation factor 2B subunit beta). [provided by Alliance of Genome Resources, Apr 2022]