The function of SYNPO2 (synaptopodin 2, ENSG00000172403) is as follows. Has an actin-binding and actin-bundling activity. Can induce the formation of F-actin networks in an isoform-specific manner (PubMed:23225103, PubMed:24005909). At the sarcomeric Z lines is proposed to act as adapter protein that links nascent myofibers to the sarcolemma via ZYX and may play a role in early assembly and stabilization of the Z lines. Involved in autophagosome formation. May play a role in chaperone-assisted selective autophagy (CASA) involved in Z lines maintenance in striated muscle under mechanical tension; may link the client-processing CASA chaperone machinery to a membrane- tethering and fusion complex providing autophagosome membranes (By similarity). Involved in regulation of cell migration (PubMed:22915763, PubMed:25883213). May be a tumor suppressor (PubMed:16885336). {ECO:0000250|UniProtKB:D4A702, ECO:0000250|UniProtKB:Q91YE8, ECO:0000269|PubMed:22915763, ECO:0000269|PubMed:23225103, ECO:0000269|PubMed:24005909, ECO:0000269|PubMed:25883213, ECO:0000305|PubMed:16885336, ECO:0000305|PubMed:20554076}. [Isoform 1]: Involved in regulation of cell migration. Can induce formation of thick, irregular actin bundles in the cell body. . [Isoform 2]: Involved in regulation of cell migration. Can induce long, well-organized actin bundles frequently orientated in parallel along the long axis of the cell showing characteristics of contractile ventral stress fibers. {ECO:0000269|PubMed:22915763, ECO:0000269|PubMed:24005909}. [Isoform 3]: Involved in regulation of cell migration. Can induce an amorphous actin meshwork throughout the cell body containing a mixture of long and short, randomly organized thick and thin actin bundles. . [Isoform 4]: Can induce long, well-organized actin bundles frequently orientated in parallel along the long axis of the cell showing characteristics of contractile ventral stress fibers. . [Isoform 5]: Involved in regulation of cell migration in part dependent on the Rho-ROCK cascade; can promote formation of nascent focal adhesions, actin bundles at the leading cell edge and lamellipodia (PubMed:22915763, PubMed:25883213). Can induce formation of thick, irregular actin bundles in the cell body; the induced actin network is associated with enhanced cell migration in vitro. {ECO:0000269|PubMed:22915763, ECO:0000269|PubMed:24005909, ECO:0000269|PubMed:25883213}.