SRF is a transcription factor that binds to the serum response element (SRE), a short sequence of dyad symmetry located 300 bp to the 5' of the site of transcription initiation of some genes (such as FOS) (PubMed:24732378). Together with MRTFA transcription coactivator, controls expression of genes regulating the cytoskeleton during development, morphogenesis and cell migration (PubMed:12732141, PubMed:19350017, PubMed:24732378). The SRF-MRTFA complex activity responds to Rho GTPase-induced changes in cellular globular actin (G-actin) concentration, thereby coupling cytoskeletal gene expression to cytoskeletal dynamics (PubMed:24732378). Required for cardiac differentiation and maturation (PubMed:15169892). Binds DNA as a multimer, probably a dimer (PubMed:15492011, PubMed:16782067). Interacts with MRTFA, forming the SRF-MRTFA nuclear complex which binds the 5'-CArG-3' consensus motif (CArG box) on DNA via SRF (PubMed:12732141, PubMed:19350017). Forms a nuclear ternary complex with MRTFA and SCAI (PubMed:19350017). Interacts with MRTFB (By similarity). Interacts with MLLT7/FOXO4, NKX3A and SSRP1 (By similarity). Interacts with ARID2 (PubMed:16782067). Interacts with SRFBP1 (PubMed:15492011). Interacts with FOXK1 (By similarity). Interacts with LPXN (By similarity). Interacts with OLFM2; the interaction promotes dissociation of SRF from the transcriptional repressor HEY2, facilitates binding of SRF to target genes and promotes smooth muscle differentiation (By similarity). Interacts with NKX3-1 (PubMed:16814806). Interacts with KAT5 (PubMed:16597624). Phosphorylated by PRKDC. Mice lacking Srf in cardiac tissue display lethal cardiac defects between 10.5 and 13.5 dpc, characterized by abnormally thin myocardium, dilated cardiac chambers, poor trabeculation and a disorganised interventricular septum.