BSG

BSG Full Name

basigin

BSG Introduction

Basigin (BSG), also called CD147 or EMMPRIN (extracellular matrix metalloproteinase inducer), is a widely expressed transmembrane glycoprotein belonging to the immunoglobulin superfamily. Unlike proteins with highly restricted tissue distribution, BSG is found on the surface of many cell types including epithelial cells, fibroblasts, leukocytes, and tumor cells, where its extracellular immunoglobulin-like domains engage in diverse molecular interactions. BSG does not function as a classical enzyme or receptor in a narrow pathway; instead, it serves as a multifunctional cell surface organizer that modulates the cellular microenvironment through binding partners such as monocarboxylate transporters (MCTs), integrins, cyclophilins, and matrix metalloproteinases. This "hub" role places BSG at the crossroads of intercellular communication and membrane protein trafficking, making it a compelling focus in studies of cell adhesion, extracellular matrix regulation, and metabolic adaptation.

Figure 1. Surfaceome tagging allows surveillance of Basigin (Bsg)-mediated monocarboxylate transporter (MCT) trafficking. (Sources: Vilen Z, et al.; 2023)

Functionally, the influence of BSG extends well beyond a single signaling axis. One of its most studied activities is the induction of matrix metalloproteinases (MMPs) in adjacent stromal and tumor cells, which facilitates extracellular matrix remodeling and can promote cell migration and invasion. In immune contexts, BSG participates in lymphocyte activation and cytokine responses, and its interaction with cyclophilin A has been linked to leukocyte recruitment and inflammatory amplification. BSG also acts as a chaperone for MCT1 and MCT4, assisting their expression at the plasma membrane and thereby supporting lactate transport and metabolic flexibility—a feature particularly pronounced in highly glycolytic cells such as activated immune cells and cancer cells. Through these mechanisms, BSG integrates structural, metabolic, and signaling cues that underpin complex biological processes.

Altered BSG expression or function has been linked to a variety of pathological states, positioning it as both a biomarker and potential therapeutic target in multiple fields. In oncology, elevated BSG levels are commonly observed across many solid tumors and hematologic malignancies, correlating with enhanced tumor invasiveness, metastasis, and poor prognosis—a reflection of its role in MMP induction and metabolic adaptation. BSG also contributes to inflammatory diseases, including rheumatoid arthritis and atherosclerosis, through modulation of leukocyte activity and matrix degradation. More recently, BSG has been implicated in viral entry mechanisms, such as serving as an attachment factor for certain viral pathogens in host cells, further widening its relevance in infectious disease research. Because of its broad involvement in disease-related biology, a range of research tools—anti-BSG antibodies for flow cytometry, IHC, and Western blot, recombinant BSG protein, and functional blocking reagents—are used to dissect its roles and to support translational efforts aimed at targeting BSG-mediated pathways.

Alternate Names for BSG

BSG; basigin; HT-7; CD147; EMMPRIN; AI115436; AI325119; gp 42; HT7 antigen; neurothelin; 5A11/Basigin; membrane glycoprotein gp42; basic immunoglobulin superfamily;

• 1. Vilen Z, et al.; Surfaceome Profiling Identifies Basigin-Chaperoned Protein Clients. Chembiochem. 2023, 24(14):e202300073.