Staufen1

Staufen1, encoded by the STAU1 gene, is a vertebrate member of the Staufen family of double-stranded RNA-binding proteins. It participates in mRNA localization, transport, and translation regulation, and is conserved from invertebrates to humans. In humans, STAU1 is broadly expressed, with notable levels in the brain and other tissues.

Structure and localization: The protein contains multiple double-stranded RNA–binding domains that enable binding to structured RNA motifs. It forms cytoplasmic ribonucleoprotein particles and associates with RNA granules, including processing bodies and stress granules, where it coordinates RNA metabolism and signaling.

Functions: STAU1 mediates localization of specific mRNAs to subcellular compartments such as dendrites and synapses, supporting local translation essential for neuronal function and development. It also participates in STAU1-mediated mRNA decay (SMD), a pathway in which STAU1 recruits UPF1 to target transcripts to promote degradation independent of canonical nonsense-mediated decay.

Regulation and interactions: STAU1 interacts with components of the cytoskeleton and translation machinery to regulate mRNA transport and translation. Through its involvement in RNA granules and decay pathways, it integrates signals related to cellular stress, development, and synaptic activity.

Clinical relevance: Alterations in STAU1 expression or function have been reported in various diseases, including neurodegenerative disorders and cancer, though the precise roles are the subject of ongoing research. STAU1 continues to be studied as a key regulator of post-transcriptional gene expression.