Protein Domain : Tumour necrosis factor receptor 5, N-terminal IPR034021

Type	Domain
Description	Tumor necrosis factor receptor superfamily member 5 (TNFRSF5), commonly known as CD40 and also as CDW40, p50 or Bp50, is widely expressed in diverse cell types including B lymphocytes, dendritic cells, platelets, monocytes, endothelial cells, and fibroblasts [ ]. It is essential in mediating a wide variety of immune and inflammatory responses, including T cell-dependent immunoglobulin class switching, memory B cell development, and germinal centre formation [, , , ]. Its natural immunomodulating ligand is CD40L, and a primary defect in the CD40/CD40L system is associated with X-linked hyper-IgM (XHIM) syndrome []. It is also involved in tumorigenesis; CD40 expression is significantly higher in gastric carcinomas and it is associated with the lymphatic metastasis of cancer cells and their tumor node metastasis (TNM) classification []. Upregulated levels of CD40/CD40L on B cells and T cells may play an important role in the immune pathogenesis of breast cancer []. Consequently, the CD40/CD40L system serves as a link between tumorigenesis, atherosclerosis, and the immune system, and offers a potential target for drug therapy for related diseases, such as cancer, atherosclerosis, diabetes mellitus, and immunological rejection [].This entry represents the N-terminal domain of TNFRSF5. TNF-receptors are modular proteins. The N-terminal extracellular part contains a cysteine-rich region responsible for ligand-binding. This region is composed of small modules of about 40 residues containing 6 conserved cysteines; the number and type of modules can vary in different members of the family [ , , ].
Short Name	TNFRSF5_N