Predicted to enable MIT domain binding activity and identical protein binding activity. Acts upstream of or within positive regulation of collateral sprouting. Predicted to be located in several cellular components, including Flemming body; endoplasmic reticulum-Golgi intermediate compartment; and extracellular exosome. Predicted to colocalize with chromatin. Is expressed in nervous system; sensory organ; submandibular gland primordium; tooth; and vibrissa. Orthologous to human IST1 (IST1 factor associated with ESCRT-III). [provided by Alliance of Genome Resources, Apr 2022]