40S ribosomal protein SA (RPSA) (RPSA)

The 40S ribosomal protein SA (RPSA), frequently referred to as the 67 kDa high-affinity laminin receptor (67LR), is a multifunctional protein that plays critical roles in both the cytoplasm and on the cell surface (UniProt P08865). In the cytoplasm, it is an essential component of the 40S ribosomal subunit, where it facilitates the assembly and stability of the translational machinery (PubMed: 17636026). On the plasma membrane, the protein acts as a high-affinity receptor for laminin, a key extracellular matrix component, thereby regulating cell adhesion, migration, and survival signaling (PubMed: 15159617). RPSA is notably overexpressed in a wide range of invasive cancers, including breast, colon, and prostate carcinomas, where its expression levels correlate with metastatic potential and poor clinical outcomes (PubMed: 24573385). Beyond its role in oncology, 67LR serves as a primary receptor for the cellular prion protein (PrPc) and various human pathogens, such as the Dengue and Sindbis viruses, making it a focal point for anti-infective research (PubMed: 11160743). Therapeutic strategies targeting RPSA include the use of small molecules like epigallocatechin-3-gallate (EGCG), which binds the receptor to inhibit its activity, and monoclonal antibodies designed to block laminin or prion binding (PubMed: 15077124). Additionally, its involvement in the internalization of amyloid-beta suggests a potential role in the pathogenesis of Alzheimer's disease (PubMed: 21952044).

Other names

67 kDa laminin receptor (67LR)37 kDa laminin receptor precursor (37LRP)Laminin-binding protein (LBP)p40LAMR1High-affinity laminin receptor

Competitive inhibition of laminin binding, downregulation of cell surface expression, and blocking of pathogen internalization (PubMed: 15077124, PubMed: 18413155).