CD40 ligand (IPR003263)

Short name: CD40L

Overlapping homologous superfamilies

Family relationships



CD40 ligand (CD40L) is a transmembrane protein belonging to the Tumour Necrosis Factor (TNF) superfamily. It can be found on the surface of B lymphocytes, dendritic cells, follicular dendritic cells, hematopoietic progenitor cells, epithelial cells, and carcinomas [PMID: 7516669]. CD40L is importance for effective interaction with CD40 and the subsequent intracellular signalling [PMID: 25479079]. It is involved in B-cell proliferation and immunoglobulin class switching [PMID: 15193700].

Cytokines can be grouped into a family on the basis of sequence, functional and structural similarities [PMID: 8095800, PMID: 1377364, PMID: 15335677]. Tumor necrosis factor (TNF) (also known as TNF-alpha or cachectin) is a monocyte-derived cytotoxin that has been implicated in tumour regression, septic shock and cachexia [PMID: 2989794, PMID: 3349526]. The protein is synthesised as a prohormone with an unusually long and atypical signal sequence, which is absent from the mature secreted cytokine [PMID: 2268312]. A short hydrophobic stretch of amino acids serves to anchor the prohormone in lipid bilayers [PMID: 2777790]. Both the mature protein and a partially-processed form of the hormone are secreted after cleavage of the propeptide [PMID: 2777790].

There are a number of different families of TNF, but all these cytokines seem to form homotrimeric (or heterotrimeric in the case of LT-alpha/beta) complexes that are recognised by their specific receptors.

GO terms

Biological Process

GO:0006955 immune response

Molecular Function

GO:0005164 tumor necrosis factor receptor binding

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.