Enables GDP-dissociation inhibitor binding activity. Involved in several processes, including positive regulation of smooth muscle cell migration; positive regulation of smooth muscle cell proliferation; and regulation of long-term neuronal synaptic plasticity. Located in several cellular components, including cytoplasmic vesicle; neuronal cell body; and perinuclear region of cytoplasm. Part of protein-containing complex. Is anchored component of synaptic vesicle membrane. Orthologous to human RAB5A (RAB5A, member RAS oncogene family). [provided by Alliance of Genome Resources, Apr 2022]