STAU1 (E5Z1N) Rabbit mAb #89056

Staufen is a multifunctional double-stranded RNA (dsRNA)-binding protein that was first described as a key regulator of development in early Drosophila oocytes (1). Two Staufen orthologues are expressed in mammals, Staufen1 (STAU1) and Staufen2 (STAU2). Although both proteins share some sequence similarity, they have largely distinct spatiotemporal expression patterns and cellular functions (2). 

STAU1 is encoded by the STAU1 gene and is ubiquitously expressed in most cell and tissue types. Multiple isoforms of STAU1 have been identified due to alternative splicing, with the two predominant isoforms being STAU1⁵⁵ and STAU1⁶³ (3,4). STAU1 plays a key role in multiple RNA processes, including splicing, translation, targeted mRNA decay (referred to as Staufen-mediated mRNA decay or SMD), and the transport of mRNA to subcellular regions during embryonic development and differentiation (1,5-10). STAU1 also transports mRNA along neuronal dendrites, contributing to localized protein synthesis and synaptic plasticity (11,12). Indeed, STAU1-deficient mice display reduced dendritic protrusions and impaired dendritic outgrowth, resulting in fewer synapses (13). STAU1 can undergo liquid-liquid phase separation and is frequently recruited to cytoplasmic foci known as stress granules (SGs), which are ribonucleoprotein (RNP) granules formed at sites of stalled mRNA translation (14,15). STAU1 has also been found to interact with ataxin-2, another SG-associated protein that is the primary cause of spinocerebellar ataxia type 2 (SCA2) when mutated (16). Cells derived from SCA2 patients display elevated levels of STAU1 protein and colocalization between STAU1 and ataxin-2 in SG-like aggregates (16). Recruitment of STAU1 to pathological protein aggregates has also been observed in other neurological disorders, such as amyotrophic lateral sclerosis (ALS) (17). STAU1 function has additionally been implicated in several types of cancer, including prostate, colorectal, and glioma (18-20).