Stress-inducible actin-binding protein that plays a role in synaptic and cognitive functions by modulating actin filamentous (F-actin) dynamics (PubMed:21969592). Mediates polymerization of globular actin to F-actin (PubMed:21969592). Also binds to, stabilizes and bundles F-actin (PubMed:21969592). Involved in synaptic function by regulating neurite outgrowth in an actin-dependent manner and for the acquisition of hippocampus-dependent cognitive function, such as learning and long-term memory (PubMed:21969592). Plays a role in the actin and microtubule cytoskeleton organization; negatively regulates focal adhesion (FA) assembly promoting malignant glial cell migration in an actin-, microtubule- and MAP1A-dependent manner. Also involved in neuroblastoma G1/S phase cell cycle progression and cell proliferation inhibition by stimulating ubiquitination of NF-kappa-B subunit RELA and NF-kappa-B degradation in a COMMD1- and actin-dependent manner. May play a role in tumor development (By similarity). Interacts with ACTB (PubMed:21969592). Interacts with F-actin (PubMed:21969592). Interacts with PRDX1 (PubMed:21969592). Interacts with COMMD1; this interaction stabilizes COMMD1 in the nucleus (By similarity). Interacts with MAP1A (By similarity). Colocalizes with F-actin (PubMed:21969592). Colocalizes with F-actin and COMMD1 in the nucleus. Colocalizes with MAP1A along actin stress fibers and membrane ruffles (By similarity). Expressed in septum, the neocortex, the CA3 region of the hippocampus and the cerebellum (at protein level). Up-regulated in the hypothalamic paraventricular nucleus (PVN) and the CA3 region of the hippocampus of the brain in response to postnatal maternal separation or food deprivation and glucocorticoids stimulation in adult animals (PubMed:21969592). Up-regulated in CA1, CA3 and dente gyrus regions of the hippocampus in response to acute social defeat stress or glucocorticoids stimulation (PubMed:25637808).