Inactive tyrosine-protein phosphatase STYX (STYX)

Inactive tyrosine-protein phosphatase STYX (STYX) is a catalytically inactive member of the dual-specificity phosphatase family structurally similar to protein tyrosine phosphatases but lacking a critical active-site cysteine, rendering it enzymatically inactive[1][2][4]. Instead of dephosphorylation, STYX functions mainly by binding to phosphorylated proteins—serving as a nuclear anchor for ERK1/2 and regulating the duration and localization of ERK signaling[1]. This role modulates processes such as Golgi polarization, cell migration, and differentiation, with implications for the invasive and metastatic potential of cancer cells[1][2]. In various cell types, including cancer cells, STYX is involved in stress response modulation by inhibiting the assembly of stress granules through protein–protein interactions rather than direct enzymatic action[3]. STYX is upregulated in several cancers and acts as a potential oncogene, indicating promise as a diagnostic or prognostic biomarker and a candidate therapeutic target[2].

Other names

Serine/threonine/tyrosine-interacting proteinphosphoserine/threonine/tyrosine interaction proteinprotein tyrosine phosphatase-like proteinMK-STYXpseudophosphatase STYX