Slingshot Homolog 1 (SSH1)

The ADF (actin-depolymerizing factor)/cofilin family is composed of stimulus-responsive mediators of actin dynamics. ADF/cofilin proteins are inactivated by kinases such as LIM domain kinase-1 (LIMK1). The SSH family appears to play a role in actin dynamics by reactivating ADF/cofilin proteins in vivo. Transcript analysis suggested that at least 6 polypeptides would be produced from these genes. SSH1 encodes 3 isoforms, SSH1L (1,049 amino acids), SSH1S (692 amino acids), and SSH1B (148 amino acids), and SSH2 encodes 2 isoforms, SSH2 (449 amino acids) and SSH2B (195 amino acids). The SSH3 protein has 471 amino acids. Besides the catalytic domain, 2 other domains are conserved between Drosophila ssh and the human SSHs and are unique to the SSH family.