F-actin cross-linking protein which is thought to anchor actin to a variety of intracellular structures. This is a bundling protein (Probable). Probably involved in vesicular trafficking via its association with the CART complex. The CART complex is necessary for efficient transferrin receptor recycling but not for EGFR degradation (PubMed:15772161). Involved in tight junction assembly in epithelial cells probably through interaction with MICALL2. Links MICALL2 to the actin cytoskeleton and recruits it to the tight junctions (By similarity). May also function as a transcriptional coactivator, stimulating transcription mediated by the nuclear hormone receptors PPARG and RARA (PubMed:22351778). Homodimer; antiparallel. Binds TRIM3 at the N-terminus (PubMed:15772161). Interacts with MICALL2 (preferentially in opened conformation); stimulated by RAB13 activation (By similarity). Identified in a complex with CASK, IQGAP1, MAGI2, NPHS1, SPTAN1 and SPTBN1 (By similarity). Identified in a IGF2BP1-dependent mRNP granule complex containing untranslated mRNAs (PubMed:17289661). Component of the CART complex, at least composed of ACTN4, HGS/HRS, MYO5B and TRIM3 (PubMed:15772161). Interacts with MAGI1 (PubMed:12042308). Interacts with PDLIM2 (By similarity). Interacts with PPARG and RARA (PubMed:22351778). Binds to VCL; this interaction triggers VCL conformational changes (PubMed:15988023). Interacts with SEPTIN14 (PubMed:33228246). Localized in cytoplasmic mRNP granules containing untranslated mRNAs. Expressed in the perinuclear rim and manchette structure in early elongating spermatids during spermiogenesis (By similarity). Nuclear translocation can be induced by the PI3 kinase inhibitor wortmannin or by cytochalasin D. Exclusively localized in the nucleus in a limited number of cell lines (breast cancer cell line MCF-7, oral floor cancer IMC-2, and bladder cancer KU-7). Widely expressed. Contains one Leu-Xaa-Xaa-Leu-Leu (LXXLL) motif that mediates interaction with nuclear receptors. The disease is caused by variants affecting the gene represented in this entry. Does not colocalize with actin cytoskeleton structures. Belongs to the alpha-actinin family. Truncated N-terminus.