描述:
CD40 Ligand (CD40L), now renamed TNFSF5 but also known as CD154, TRAP and gp39,
is a 34-39 kDa type II transmembrane glycoprotein that belongs to the TNF
superfamily . Human CD40L is 261 amino acids (aa) in length and consists of a 22 aa
cytoplasmic domain, a 24 aa transmembrane segment, and a 215 aa extracellular region
that consists of multiple β-strands and one N-linked glycosylation site. Although carbohydrates
are present, they are not necessary for activity. As with other TNF superfamily members,
CD40L will exist as a trimer, both as a membrane bound and soluble form. The soluble form
is 18 kDa in size and about 150 aa in length, and arises from intracellular proteolytic processing.
As a trimer, the soluble form is bioactive.Multiple mutations and alternate splice forms of
CD40L exist, often associated with pathology and leading to truncated or nontrimerizable
forms of CD40L. While CD40L is a ligand for CD40, the ligation of CD40L by CD40 initiates
bidirectional signaling in both CD40 and CD40L expressing cells. The extracellular region of
human CD40L is 99%, 88%, 86%, 82%, 75% and 75% aa identical to the extracellular regions
of CD40L in rhesus monkey, bovine, porcine, canine, mouse and rat, respectively. CD40L
binds to both CD40 and to integrin αIIbβ3 (CD41). In the cell membrane, it also associates
with a unique splice variant of CD28 (CD28i) that may facilitate CD40L signal transduction.
CD40L is expressed by monocytes, NK cells, mast cells, basophils, smooth muscle cells,
endothelial cells, dendritic cells, activated and resting B cells, plus activated platelets and
CD4+ T cells. CD40L ligation of CD40 on dendritic cells (DC) initiates DC maturation and
differentiation. CD40L signaling into naïve B cells promotes germinal center formation and
isotope switching. With IL21, CD40L generates IgA plus IgG3; with IL-4, CD40L generates
IgG1 secretion.
原厂资料:
CD40 Ligand (CD40L), now renamed TNFSF5 but also known as CD154, TRAP and gp39,
is a 34-39 kDa type II transmembrane glycoprotein that belongs to the TNF
superfamily . Human CD40L is 261 amino acids (aa) in length and consists of a 22 aa
cytoplasmic domain, a 24 aa transmembrane segment, and a 215 aa extracellular region
that consists of multiple β-strands and one N-linked glycosylation site. Although carbohydrates
are present, they are not necessary for activity. As with other TNF superfamily members,
CD40L will exist as a trimer, both as a membrane bound and soluble form. The soluble form
is 18 kDa in size and about 150 aa in length, and arises from intracellular proteolytic processing.
As a trimer, the soluble form is bioactive.Multiple mutations and alternate splice forms of
CD40L exist, often associated with pathology and leading to truncated or nontrimerizable
forms of CD40L. While CD40L is a ligand for CD40, the ligation of CD40L by CD40 initiates
bidirectional signaling in both CD40 and CD40L expressing cells. The extracellular region of
human CD40L is 99%, 88%, 86%, 82%, 75% and 75% aa identical to the extracellular regions
of CD40L in rhesus monkey, bovine, porcine, canine, mouse and rat, respectively. CD40L
binds to both CD40 and to integrin αIIbβ3 (CD41). In the cell membrane, it also associates
with a unique splice variant of CD28 (CD28i) that may facilitate CD40L signal transduction.
CD40L is expressed by monocytes, NK cells, mast cells, basophils, smooth muscle cells,
endothelial cells, dendritic cells, activated and resting B cells, plus activated platelets and
CD4+ T cells. CD40L ligation of CD40 on dendritic cells (DC) initiates DC maturation and
differentiation. CD40L signaling into naïve B cells promotes germinal center formation and
isotope switching. With IL21, CD40L generates IgA plus IgG3; with IL-4, CD40L generates
IgG1 secretion.