The hematopoietic growth factor KL is encoded by the Sl locus and is the ligand of the c-kit receptor, the gene product of the W locus.
Mutations at the steel locus (Sl) of the mouse affect the same cellular targets as mutations at the white spotting locus (W), which is allelic with the c-kit proto-oncogene. We show that KL, a hematopoietic growth factor obtained from conditioned medium of BALB/c 3T3 fibroblasts that stimulates the proliferation of mast cells and early erythroid progenitors, specifically binds to the c-kit receptor. The predicted amino acid sequence of isolated KL-specific cDNA clones suggests that KL is synthesized as an integral transmembrane protein. Linkage analysis maps the KL gene to the Sl locus on mouse chromosome 10, and KL sequences are deleted in the genome of the Sl mouse. These results indicate that the Sl locus encodes the ligand of the c-kit receptor, KL.
Molecular Biology Program, Sloan Kettering Institute, New York, New York.
E
E
Huang
K
K
Nocka
D R
DR
Beier
T Y
TY
Chu
J
J
Buck
H W
HW
Lahm
D
D
Wellner
P
P
Leder
P
P
Besmer
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D005796:Genes; D016298:Hematopoietic Cell Growth Factors / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019009:Proto-Oncogene Proteins c-kit; D014158:Transcription, Genetic
D016298:Hematopoietic Cell Growth Factors; D008024:Ligands; D011518:Proto-Oncogene Proteins; D004247:DNA; D011505:Protein-Tyrosine Kinases; D019009:Proto-Oncogene Proteins c-kit