Enables GPI anchor binding activity; GTPase activator activity; and protein kinase binding activity. Involved in several processes, including T cell receptor signaling pathway; focal adhesion assembly; and negative regulation of neuron projection development. Located in several cellular components, including growth cone; neuron projection membrane; and neuronal cell body membrane. Is anchored component of plasma membrane. Biomarker of retinal disease and retinal ischemia. Orthologous to human THY1 (Thy-1 cell surface antigen). [provided by Alliance of Genome Resources, Apr 2022]