There are several isomers of fibroblast growth factor (FGF). The main role in arteriosclerosis is bFGF (basic fibroblast growth factor). BFGF can be secreted by endothelial cells, smooth muscle cells and macrophages. . Its role is to promote the migration of endothelial cells and the proliferation of smooth muscle cells, but not to allow smooth muscle cells to migrate. Can promote the formation of new blood vessels and repair damaged endothelial cells. FGF is considered to be a factor for promoting formation of lesions, but it also has a positive side from a repair perspective.
Fibroblast growth factor receptor (FGFR) is a receptor-type protein tyrosine kinase. Currently known FGFR mainly includes 4 types, namely FGFR1, FGFR2, FGFR3 and FGFR4. It has been clinically found that FGFR overexpression and activation of tumor tissues in a variety of cancers can promote tumor angiogenesis and tumor cell division and proliferation. Therefore, fibroblast growth factor receptors are widely regarded as an important class of anti-tumor drug targets, and have attracted widespread attention from pharmacists in various countries. In previous research, a "binding gap" in the ATP-binding domain of the FGFR1 protein was discovered, and a novel FGFR1 inhibitor design idea was proposed for the spatial structure of the "gap".
Fibroblast Growth Factor (FGF) Proteins
FGF1 is a growth factor and signaling protein encoded by the FGF1 gene. It is synthesized into a 155 amino acid peptide, FGF-1 has no definite signal sequence, so it is not secreted through the classical pathway, but it does form a disulfide-linked dimer inside the cell. It binds to protein complexes on the cell membrane (including S100A13 and Syt1), helping to flip it through the membrane to the outside of the cell. Once in the reduced state of surrounding tissues, the dimer is broken down into monomeric FGF1, which can enter the systemic circulation or be isolated in tissues that bind to the extracellular matrix heparan sulfate proteoglycan. FGF1 can then bind and exert its function through a specific fibroblast growth factor receptor (FGFR) protein, which itself constitutes a closely related family of molecules. In addition to its extracellular activity, FGF1 can also function within cells. The protein has a nuclear localization sequence (NLS), but the way FGF1 reaches the nucleus is not clear. It seems that some cell surface receptor binding is necessary, and then its internalization and translocation to the nucleus, then it can interact with FGFRs Nuclear isomers. This is different from FGF2, which can also activate nuclear FGFR, but has splice variants whose proteins never leave the cell and enter the nucleus directly.
Figure 1. Structure of the FGF1 protein.
FGF2, also known as basic fibroblast growth factor (bFGF) and FGF-β, is a growth factor and signaling protein encoded by the FGF2 gene. It is mainly synthesized as a 155 amino acid peptide, producing an 18 kDa protein. Generally, the 155 aa/18 kDa low molecular weight (LMW) form is considered cytoplasmic and can be secreted from cells, while the high molecular weight (HMW) form is directed against the nucleus. Fibroblast growth factor protein was first purified in 1975, but shortly thereafter, others isolated basic FGF, heparin-binding growth factor 2 and endothelial cell growth factor 2 under different conditions. Gene sequencing showed that the group was actually the same FGF2 protein and was a member of the FGF protein family. FGF2 binds and functions through specific fibroblast growth factor receptor (FGFR) proteins, which itself constitute a closely related family of molecules.
Figure 2. Structure of FGF2 protein.
Fibroblast growth factor 10 is a protein encoded by the FGF10 gene in humans. The protein encoded by this gene is a member of the fibroblast growth factor (FGF) family. FGF family members have extensive mitogenic and cell survival activities and are involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. Fibroblast growth factor 10 is a paracrine signaling molecule that first appears in the development of limb buds and organs. FGF10 begins the development of the limbs and participates in the morphogenetic branches of multiple organs such as the lungs, skin, ears, and salivary glands.
Figure 3. Structure of FGF10 protein.
Fibroblast growth factor 12 is a protein encoded by the FGF12 gene in humans. FGF family members have extensive mitogenic and cell survival activities and are involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. This growth factor lacks the N-terminal signal sequence found in most FGF family members, but it contains a cluster of basic residues that have been shown to serve as nuclear localization signals. When transfected into mammalian cells, the protein accumulated in the nucleus but was not secreted. The specific function of the gene has not been determined. Two alternative splicing transcription variants encoding different isoforms have been reported.
Figure 4. Structure of FGF12 protein.
1. Olsen SK.; et al. Fibroblast growth factor (FGF) homologous factors share structural but not functional homology with FGFs. The Journal of Biological Chemistry. 2003, 278 (36): 34226–36.