Protein phosphatase Slingshot homolog 3 (SSH3)

Protein phosphatase Slingshot homolog 3 (SSH3) is a member of the Slingshot family of dual-specificity phosphatases that serves as a key regulator of actin filament dynamics. Its primary biological role is the dephosphorylation and subsequent activation of cofilin, an actin-binding protein that severs actin filaments to facilitate rapid cytoskeleton remodeling (UniProt Q8TE77). By modulating the activation state of cofilin, SSH3 plays an essential role in cellular processes such as chemotaxis, cell migration, and cytokinesis (PubMed: 12134152). In clinical contexts, SSH3 is frequently implicated in the progression of various malignancies, where its overexpression correlates with increased tumor cell invasion and metastatic potential, particularly in gastric and breast cancers (PubMed: 25605116). Although SSH3 is recognized as a promising therapeutic target for preventing cancer metastasis, there are currently no FDA-approved drugs or clinical-stage candidates specifically targeting this enzyme. Development of SSH3 inhibitors faces significant hurdles, including the need for high isoform selectivity and the risk of systemic toxicity due to the fundamental role of actin regulation in normal physiological functions.

Other names

Slingshot-3SSH-3LSlingshot homolog 3hSSH3LSSH3-like protein

SSH3 specifically dephosphorylates and activates cofilin at its Ser-3 residue. Once activated, cofilin severs actin filaments and promotes the turnover of the actin cytoskeleton, which is a prerequisite for cell motility and morphological changes (UniProt Q8TE77).