Marginal zone B- and B1-cell-specific protein (MZB1) (MZB1)

Marginal zone B- and B1-cell-specific protein (MZB1), also known as p58 or PACAP, is an endoplasmic reticulum (ER)-resident chaperone protein primarily expressed in B-cell subsets, particularly marginal zone B cells and plasma cells (UniProt: Q8WU39). It plays a critical role in the late stages of B-cell differentiation, specifically facilitating the assembly and secretion of multimeric IgM antibodies and regulating calcium homeostasis within the ER (PubMed: 20644168). MZB1 also promotes integrin-mediated cell adhesion, which is vital for the localization of B cells and their interaction with the microenvironment (PubMed: 20644168). In clinical contexts, MZB1 is significantly overexpressed in various B-cell malignancies, such as multiple myeloma and chronic lymphocytic leukemia, where it correlates with poor prognosis, increased secretory activity, and disease progression (PubMed: 30249024). Furthermore, its involvement in autoantibody production makes it a potential target for autoimmune disorders like systemic lupus erythematosus (PubMed: 33461563). Although no targeted therapies against MZB1 are currently approved, it represents a promising therapeutic target for modulating antibody-mediated immune responses and treating B-cell-derived malignancies (PubMed: 30249024).

Other names

MZB1p58MEDA-7PACAPPlasma cell-induced ER proteinMesenteric estrogen-dependent adipogenesis 7

Inhibition of chaperone function to disrupt IgM assembly and induce ER stress-mediated apoptosis in malignant plasma cells (PubMed: 30249024)