Stress-inducible actin-binding protein that plays a role in synaptic and cognitive functions by modulating actin filamentous (F-actin) dynamics. Mediates polymerization of globular actin to F-actin. Also binds to, stabilizes and bundles F-actin. 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 (By similarity). 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 (PubMed:20543869). 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 (PubMed:10564580, PubMed:28604741). May play a role in tumor development (PubMed:10564580). Interacts with ACTB (PubMed:21969592, PubMed:28604741). Interacts with COMMD1; this interaction stabilizes COMMD1 in the nucleus (PubMed:28604741). Interacts with MAP1A (PubMed:20543869). Interacts with PRDX1 (PubMed:21969592). Interacts with F-actin (By similarity). Colocalizes with F-actin and COMMD1 in the nucleus (PubMed:28604741). Colocalizes with MAP1A along actin stress fibers and membrane ruffles (PubMed:20543869). Widely expressed (PubMed:10564580). Expressed in neurons (PubMed:20543869). Expressed in malignant glial tumors (PubMed:20543869). Expression is reduced or absent in a number of cancer cell lines (PubMed:10564580). May be due to an intron retention. Belongs to the FAM107 family.