Cloning and characterization of cDNAs encoding two forms of avian stem cell factor

摘要

Stem cell factor (SCF), also known as Steel factor, is a transmembrane cytokine involved in several developmental processes and the ligand for the receptor lyrosine kinase c-kit. In several mammalian species, two isoforms of stem cell factor have been reported, a long form in which soluble SCI is released after proteolytic cleavage of the extracellular domain and a short membrane-anchored form in which a region containing a cleavage site is deleted. Currently, only the longer, soluble form has been identified in birds. Therefore, the cDNAs encoding two forms of quail stem cell factor (qSCF) were obtained using RT-PCR with nested primers. The deduced amino acid sequence of the long form of qSCF showed a high degree of homology with chicken (98%) and relatively low homology (~ 53%) with various mammalian SCFs, Northern blot analysis with the qSCF cDNA revealed the expression of a 5.9 and a 2.7 kb transcript in several quail tissues.