Stem Cell Factor (SCF) Human Active Protein

This gene encodes the ligand of the tyrosine-kinase receptor encoded by the KIT locus. This ligand is a pleiotropic factor that acts in utero in germ cell and neural cell development, and hematopoiesis, all believed to reflect a role in cell migration. In adults, it functions pleiotropically, while mostly noted for its continued requirement in hematopoiesis. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

SCF: Ligand for the receptor-type protein-tyrosine kinase KIT. Plays an essential role in the regulation of cell survival and proliferation, hematopoiesis, stem cell maintenance, gametogenesis, mast cell development, migration and function, and in melanogenesis. KITLG/SCF binding can activate several signaling pathways. Promotes phosphorylation of PIK3R1, the regulatory subunit of phosphatidylinositol 3-kinase, and subsequent activation of the kinase AKT1. KITLG/SCF and KIT also transmit signals via GRB2 and activation of RAS, RAF1 and the MAP kinases MAPK1/ERK2 and/or MAPK3/ERK1. KITLG/SCF and KIT promote activation of STAT family members STAT1, STAT3 and STAT5. KITLG/SCF and KIT promote activation of PLCG1, leading to the production of the cellular signaling molecules diacylglycerol and inositol 1,4,5- trisphosphate. KITLG/SCF acts synergistically with other cytokines, probably interleukins. Homodimer, non-covalently linked (Probable). Heterotetramer with KIT, binding two KIT molecules; thereby mediates KIT dimerization and subsequent activation by autophosphorylation. Belongs to the SCF family. 3 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral

Chromosomal Location of Human Ortholog: 12q22

Cellular Component: extracellular space; cytoskeleton; cytoplasm; integral to membrane; extracellular region; plasma membrane

Molecular Function: protein binding; growth factor activity; cytokine activity; stem cell factor receptor binding

Biological Process: epidermal growth factor receptor signaling pathway; phosphoinositide-mediated signaling; fibroblast growth factor receptor signaling pathway; nerve growth factor receptor signaling pathway; embryonic hemopoiesis; germ cell programmed cell death; male gonad development; signal transduction; positive regulation of MAP kinase activity; cell proliferation; positive regulation of peptidyl-tyrosine phosphorylation; positive regulation of melanocyte differentiation; negative regulation of mast cell apoptosis; innate immune response; positive regulation of myeloid leukocyte differentiation; positive regulation of Ras protein signal transduction; cell adhesion; neural crest cell migration; positive regulation of DNA replication

Disease: Hyperpigmentation, Familial Progressive, 2; Skin/hair/eye Pigmentation, Variation In, 7