POU domain class 2-associating factor 1; Transcriptional coactivator that specifically associates with either OCT1 or OCT2. It boosts the OCT1 mediated promoter activity and to a lesser extent, that of OCT2. It has no intrinsic DNA-binding activity. It recognizes the POU domains of OCT1 and OCT2. It is essential for the response of B-cells to antigens and required for the formation of germinal centers; Belongs to the POU2AF1 family.

Polymeric immunoglobulin receptor; This receptor binds polymeric IgA and IgM at the basolateral surface of epithelial cells. The complex is then transported across the cell to be secreted at the apical surface. During this process a cleavage occurs that separates the extracellular (known as the secretory component) from the transmembrane segment.

Tumor necrosis factor receptor superfamily member 17; Receptor for TNFSF13B/BLyS/BAFF and TNFSF13/APRIL. Promotes B-cell survival and plays a role in the regulation of humoral immunity. Activates NF-kappa-B and JNK.

B-lymphocyte antigen CD19; Functions as coreceptor for the B-cell antigen receptor complex (BCR) on B-lymphocytes. Decreases the threshold for activation of downstream signaling pathways and for triggering B-cell responses to antigens. Activates signaling pathways that lead to the activation of phosphatidylinositol 3-kinase and the mobilization of intracellular Ca(2+) stores. Is not required for early steps during B cell differentiation in the blood marrow. Required for normal differentiation of B-1 cells (By similarity). Required for normal B cell differentiation and proliferation in [...]

B-cell CLL/lymphoma 9 protein; Involved in signal transduction through the Wnt pathway. Promotes beta-catenin's transcriptional activity (By similarity). Belongs to the BCL9 family.

B-cell antigen receptor complex-associated protein alpha chain; Required in cooperation with CD79B for initiation of the signal transduction cascade activated by binding of antigen to the B- cell antigen receptor complex (BCR) which leads to internalization of the complex, trafficking to late endosomes and antigen presentation. Also required for BCR surface expression and for efficient differentiation of pro- and pre-B-cells. Stimulates SYK autophosphorylation and activation. Binds to BLNK, bringing BLNK into proximity with SYK and allowing SYK to phosphorylate BLNK. Also interacts wit [...]

B-lymphocyte antigen CD20; B-lymphocyte-specific membrane protein that plays a role in the regulation of cellular calcium influx necessary for the development, differentiation, and activation of B-lymphocytes. Functions as a store-operated calcium (SOC) channel component promoting calcium influx after activation by the B-cell receptor/BCR.

CD27 antigen; Receptor for CD70/CD27L. May play a role in survival of activated T-cells. May play a role in apoptosis through association with SIVA1.

Complement receptor type 2; Receptor for complement C3, for the Epstein-Barr virus on human B-cells and T-cells and for HNRNPU. Participates in B lymphocytes activation.