Growth factor (protein)
In cell biology, growth factors are proteins that are transmitted as signals from one cell to another and thus transmit information. They also regulate a wide variety of intracellular processes in their function as " signal proteins " and play a particular role in the development of multicellular organisms . The signal is usually transmitted via the growth factor binding to a specific receptor in the cell membrane.
Families of growth factors
There are six major families of growth factors:
- FGF family ( fibroblast growth factor )
- TGF family ( transforming growth factor )
- Hedgehog
- Wingless
- Delta and Serrate
- Ephrine
Growth factors are either secreted, i.e. released by cells into the environment, or they are membrane-based . They work by being recognized by a receptor on the surface of the target cell. Only cells that carry the specific receptor for the respective growth factor (the ligand) can respond to the signal. When bound to its ligand, this receptor generates a signal through a change in conformation inside the cell, which via further signal transmissions leads to the activation or deactivation of genes. A typical example of how growth factors work is angiogenesis .
Growth factors with different signal inductions
A large number of growth factors with different signal inductions are known today. Examples are:
- Fibroblast growth factor (FGF)
- Transforming growth factor (TGF)
- Platelet Derived Growth Factor (PDGF)
- Epidermal Growth Factor (EGF)
- Granulocyte-Macrophage Colony Stimulating Factor (GMCSF)
- Vascular Endothelial Growth Factor (VEGF)
- Insulin -like Growth Factors (IGF)
- Hepatocyte Growth Factor (HGF)
- Interleukin -1B, -8 (IL-1B, IL-8)
- Nerve growth factor (Nerve Growth Factor, NGF)
- Haematopoietic growth factors: erythropoietin and colony stimulating factors such as G-CSF
Hematopoietic growth factors
Hematopoietic growth factors such as erythropoietin or granulocyte-colony-stimulating factor (G-CSF) are glycoprotein hormones that regulate the proliferation and differentiation of the hematopoietic progenitor cells and the function of mature blood cells.
See also
- Somatropin (growth hormone)
Individual evidence
- ↑ Reference: Hoffbrand AV Basic Course in Hematology, Blackwell Verlag, 2nd edition 2003.