a member of the TNF-receptor superfamily. This receptor for CD40L mediates a broad variety of immune and inflammatory responses including T cell-dependent immunoglobulin class switching, memory B cell development, and germinal center formation. Defects in CD40 are the cause of hyper-IgM immunodeficiency type 3 (HIGM3). HIGM3 is an autosomal recessive disorder which includes an inability of B cells to undergo isotype switching, one of the final differentiation steps in the humoral immune system, an inability to mount an antibody-specific immune response, and a lack of germinal center formation. Two alternatively spliced isoforms have been reported. Isoform I is a type I membrane protein; isoform II is secreted. Note: This description may include information from UniProtKB.
Protein type: Membrane protein, integral; Receptor, cytokine
Cellular Component: cell soma; cell surface; cytoplasm; external side of plasma membrane; integral component of plasma membrane; intracellular membrane-bound organelle; plasma membrane
Molecular Function: antigen binding; enzyme binding; protein binding; protein domain specific binding; receptor activity; signal transducer activity; tumor necrosis factor-activated receptor activity; ubiquitin protein ligase binding
Biological Process: B cell proliferation; cellular calcium ion homeostasis; defense response to protozoan; defense response to virus; immune response; immune response-regulating cell surface receptor signaling pathway; inflammatory response; multicellular organism development; platelet activation; positive regulation of angiogenesis; positive regulation of B cell proliferation; positive regulation of blood vessel endothelial cell migration; positive regulation of GTPase activity; positive regulation of I-kappaB kinase/NF-kappaB signaling; positive regulation of interleukin-12 production; positive regulation of isotype switching to IgG isotypes; positive regulation of MAP kinase activity; positive regulation of NF-kappaB transcription factor activity; positive regulation of protein phosphorylation; positive regulation of transcription from RNA polymerase II promoter; positive regulation of tyrosine phosphorylation of STAT protein; protein complex assembly; protein kinase B signaling; regulation of cell proliferation; regulation of immune response; regulation of immunoglobulin secretion; response to cobalamin; response to lipopolysaccharide; tumor necrosis factor-mediated signaling pathway