Lupus La protein (SSB) (SSB)

The Lupus La protein (SSB) is a highly conserved RNA-binding protein that functions primarily as an RNA chaperone [UniProt P05455]. It binds to the 3' uridylate tail of all nascent RNA polymerase III transcripts, such as pre-tRNAs and 5S rRNAs, protecting them from digestion and assisting in their correct folding and maturation [PubMed: 16043498]. While predominantly nuclear, it can translocate to the cytoplasm to regulate the translation of specific mRNAs, including those with internal ribosome entry sites (IRES) [NCBI Gene: 6741]. Clinically, La/SSB is most recognized as a major autoantigen; autoantibodies against it are hallmark biomarkers for Sjögren's syndrome and systemic lupus erythematosus (SLE) [StatPearls: Sjögren Syndrome]. In oncology, La/SSB is frequently overexpressed and is associated with increased cell proliferation and migration by stabilizing oncogenic mRNAs, making it a potential therapeutic target for cancer [PubMed: 23812433]. Although no direct small-molecule inhibitors are currently FDA-approved, experimental strategies targeting its RNA-binding domain, such as with epigallocatechin gallate, are being explored to inhibit viral replication and tumor growth [Journal of Biological Chemistry].

Other names

Sjögren syndrome type B antigenLa autoantigenSS-BLa ribonucleoproteinLARP3

Inhibition of RNA-binding and chaperone activity