Abcam's WISP-1 (CCN4) Human ELISA (Enzyme-Linked Immunosorbent Assay) kit is an in vitro enzyme-linked immunosorbent assay designed for the quantitative measurement of Human WISP-1 in serum, plasma (collect plasma using EDTA as an anticoagulant. Heparin and Citrate are not recommended as anticoagulants for use in this assay) and cell culture supernatants.
This assay employs an antibody specific for Human WISP-1coated on a 96-well plate. Standards and samples are pipetted into the wells and WISP-1 present in a sample is bound to the wells by the immobilized antibody. The wells are washed and biotinylated anti-Human WISP-1 antibody is added. After washing away unbound biotinylated antibody, HRP-conjugated streptavidin is pipetted to the wells. The wells are again washed, a TMB substrate solution is added to the wells and color develops in proportion to the amount of WISP-1 bound. The Stop Solution changes the color from blue to yellow, and the intensity of the color is measured at 450 nm.
The WISP-1/CCN4 gene encodes a member of the WNT1 inducible signaling pathway (WISP) protein subfamily, which belongs to the connective tissue growth factor (CTGF) family. WNT1 is a member of a family of cysteine-rich, glycosylated signaling proteins that mediate diverse developmental processes. The CTGF family members are characterized by four conserved cysteine-rich domains: von Willebrand factor type C module, thrombospondin domain, insulin-like growth factor-binding domain and C-terminal cystine knot-like domain. This gene may be downstream in the WNT1 signaling pathway that is relevant to malignant transformation. It is expressed at a high level in fibroblast cells, and overexpressed in colon tumors. The encoded protein binds to decorin and biglycan, two members of a family of small leucine-rich proteoglycans present in the extracellular matrix of connective tissue, and possibly prevents the inhibitory activity of decorin and biglycan in tumor cell proliferation. It also attenuates p53-mediated apoptosis in response to DNA damage through activation of the Akt kinase. It is 83% identical to the mouse protein at the amino acid level. Multiple alternatively spliced transcript variants have been identified.