Enables GTPase activating protein binding activity and protein N-terminus binding activity. Involved in several processes, including cellular response to oxygen-glucose deprivation; negative regulation of GTPase activity; and regulation of macroautophagy. Located in several cellular components, including cytosol; growth cone; and perinuclear region of cytoplasm. Part of protein-containing complex. Used to study obesity. Human ortholog(s) of this gene implicated in intellectual disability; lymphangioleiomyomatosis; tuberous sclerosis; and tuberous sclerosis 1. Orthologous to human TSC1 (TSC complex subunit 1). [provided by Alliance of Genome Resources, Apr 2022]