| First Author | Broudy VC | Year | 2001 |
| Journal | Cytokine | Volume | 15 |
| Issue | 4 | Pages | 188-95 |
| PubMed ID | 11563879 | Mgi Jnum | J:146728 |
| Mgi Id | MGI:3838294 | Doi | 10.1006/cyto.2001.0907 |
| Citation | Broudy VC, et al. (2001) The fifth immunoglobulin-like domain of the Kit receptor is required for proteolytic cleavage from the cell surface. Cytokine 15(4):188-95 |
| abstractText | Stem cell factor (SCF) initiates its biological effects by binding to its receptor Kit. Cell surface Kit is proteolytically cleaved to generate soluble Kit. Structure-function analysis of the extracellular region of Kit has implicated the first three immunoglobulin-like domains in SCF binding, and the fourth immunoglobulin-like domain in receptor dimerization. However, the role of the fifth immunoglobulin-like domain is unknown. To test the hypothesis that the fifth immunoglobulin-like domain is important for proteolytic cleavage of Kit from the cell surface, we constructed a mutant form of Kit in which the first four immunoglobulin-like domains are linked to the transmembrane and cytoplasmic domains (designated Kit-Del5). Kit-wild type (Kit-WT) and Kit-Del5 were expressed in the murine mast cell line IC2. Flow cytometry demonstrated that both Kit-WT and Kit-Del5 are displayed on the IC2 cell surface, and immunoblotting confirmed the presence of Kit proteins of the expected molecular weights, 154 kDa and 134 kDa, respectively. Although IC2-Kit-WT cells proteolytically cleave cell surface Kit, generating a 98 kDa soluble form of Kit, IC2-Kit-Del5 cells do not. These findings demonstrate that the fifth immunoglobulin-like domain of Kit is required for proteolytic cleavage of Kit from the cell surface. |
