stamcellfaktor

Stamcellfaktor, also known as stem cell factor (SCF) or KIT ligand (KITLG), is a cytokine that binds to the KIT receptor (CD117). The KITLG gene encodes the protein in humans. SCF exists in both membrane-bound and soluble forms, produced by stromal and support cells in various tissues.

SCF acts on cells expressing KIT, including hematopoietic stem and progenitor cells, mast cells, melanocytes, and germ cells. Binding to KIT activates its tyrosine kinase activity, triggering signaling pathways such as PI3K-Akt, Ras-MAPK, and JAK-STAT that promote survival, proliferation, differentiation, and migration. The balance of SCF forms and signaling modulates cell fate and niche interactions.

Biological roles: in the bone marrow microenvironment, SCF supports hematopoiesis and stem cell maintenance; in embryos it contributes to germ cell development and melanocyte function; in adult tissues it influences mast cell maturation and skin pigmentation. The molecule participates in development and tissue homeostasis and can interact with other cytokines.

Clinical and research relevance: SCF is used in research to expand hematopoietic progenitors and to mobilize stem cells for transplantation, often in combination with other growth factors. Dysregulation of KIT signaling, including KITLG variations or KIT mutations, is linked to mast cell disorders, pigmentary conditions, and certain leukemias. Deficiency in model organisms causes anemia, infertility, and pigmentation defects.