The c-kit receptor transduces the stem cell factor-triggered growth signal in murine interleukin-3-dependent cell...

The stem cell factor is a glycoprotein hormone which regulates the proliferation and differentiation of primitive hematopoietic cells through its interaction with a tyrosine kinase transmembrane receptor which is encoded by the c-kit proto-oncogene. To examine whether a murine c-kit receptor can be functional in murine interleukin-3 (mIL-3)-dependent hematopoietic cell line, we introduced the murine c-kit cDNA into mIL-3-dependent pro-B cell line Ba/F3. One of the resulting clones, Ba/F3 clone BF-K96, expressed the 140 kDa protein recognized by anti-c-kit monoclonal antibody and the expressed c-kit receptor protein on the cell surface bound to a radiolabeled soluble form of murine stem cell factor (mSCF) with high affinity. BF-K96 clone expressing the c-kit receptor could proliferate in response to mSCF in the absence of mIL-3. The cell clone could also grow in co-culture with mouse 3T3 cells which are endogeneously expressing a membrane-associated type of mSCF on their cell surfaces. These findings demonstrate that the c-kit receptor expressed on mIL-3-dependent hematopoietic cell line Ba/F3 transduce the mSCF-dependent growth signal, indicating that established cell clone will provide a unique cellular system for the study of SCF/c-kit signal transduction mechanism.