Deletion mutagenesis of stem cell factor defines the C-terminal sequences essential for its biological activity.
We constructed a series of murine stem cell factor (mSCF) cDNAs which were sequentially truncated at the 3' termini. The resultant six mutant cDNA encode N-terminal 183, 179, 162, 149, 142 and 133 amino acid residues of the mature mSCF protein fused to the heterogeneous C-terminal peptides derived from the linker sequences. Each mutant cDNA was transiently expressed in COS cells, and the cultured supernatant was assayed for its ability to support the growth of a human factor-dependent cell line, TF-1 and to enhance colony formation by murine hematopoietic progenitor cells. The results showed that as few as N-terminal 142 but not 133 amino acid residues of mSCF remained biologically active in vitro, suggesting that the region of 9 amino acids from Asp134 to Ser142 containing a Cys138-mediated disulfide bond may contribute to the C-terminal end of the active subdomain of mSCF.
Nishikawa
M
M
Department of Hematology and Oncology, University of Tokyo, Japan.
Tojo
A
A
Ikebuchi
K
K
Katayama
K
K
Fujii
N
N
Ozawa
K
K
Asano
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D016298:Hematopoietic Cell Growth Factors / Q000235:genetics* / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000494:pharmacology; D017384:Sequence Deletion; D019089:Stem Cell Factor; D014162:Transfection
D016298:Hematopoietic Cell Growth Factors; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D019089:Stem Cell Factor