FGF domain, beta-trefoil fold, found in acidic and basic fibroblast growth factor (FGF) superfamily; The FGF superfamily includes FGF1-23 and similar proteins. FGFs are mitogens, which stimulate growth or differentiation of cells of mesodermal or neuroectodermal origin. They play essential roles in patterning and differentiation during vertebrate embryogenesis and have neurotrophic activities. FGFs have a high affinity for heparan sulfate proteoglycans and require heparan sulfate to activate one of four cell surface FGF receptors. Upon binding to FGF, the receptors dimerize, and their intracellular tyrosine kinase domains become active. The structure of FGFs is typical of the beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTEKTGREWYVALNKRGKAKRGCSPRVKPQHISTHFLPRF 76
Cdd:cd23317   58 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASATHRNHRTGREWYVALNKRGKAKRGCSPRVKPQHISTHFLPRF 133

FGF domain, beta-trefoil fold, found in fibroblast growth factor 5 (FGF5) and similar proteins; FGF5, also called heparin-binding growth factor 5 (HBGF5), or Smag-82, plays an important role in the regulation of cell proliferation and cell differentiation. It is required for normal regulation of the hair growth cycle. It functions as an inhibitor of hair elongation by promoting progression from anagen, the growth phase of the hair follicle, into catagen the apoptosis-induced regression phase. FGF5 interacts with fibroblast growth factor receptors, FGFR1 and FGFR2. Affinity between FGFs and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF-5 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTEKTGREWYVALNKRGKAKRGCSPRVKPQHISTHFLPRF 76
Cdd:cd23317   58 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASATHRNHRTGREWYVALNKRGKAKRGCSPRVKPQHISTHFLPRF 133

Fibroblast growth factor; Fibroblast growth factors are a family of proteins involved in growth and differentiation in a wide range of contexts. They are found in a wide range of organizms, from nematodes to humans. Most share an internal core region of high similarity, conserved residues in which are involved in binding with their receptors. On binding, they cause dimerization of their tyrosine kinase receptors leading to intracellular signalling. There are currently four known tyrosine kinase receptors for fibroblast growth factors. These receptors can each bind several different members of this family. Members of this family have a beta trefoil structure. Most have N-terminal signal peptides and are secreted. A few lack signal sequences but are secreted anyway; still others also lack the signal peptide but are found on the cell surface and within the extracellular matrix. A third group remain intracellular. They have central roles in development, regulating cell proliferation, migration and differentiation. On the other hand, they are important in tissue repair following injury in adult organizms.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 620597367    1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRtektGREWYVALNKRGKAKRGcsPRVKPQHISTHFL 73
Cdd:pfam00167  58 MNKKGRLYGSKNFTDECVFKERLLENNYNTYASAKYS----GRGWYVGLNKKGRPKRG--SKTKPGQKAAHFL 124

FGF domain, beta-trefoil fold, found in fibroblast growth factor 5 (FGF5) and similar proteins; FGF5, also called heparin-binding growth factor 5 (HBGF5), or Smag-82, plays an important role in the regulation of cell proliferation and cell differentiation. It is required for normal regulation of the hair growth cycle. It functions as an inhibitor of hair elongation by promoting progression from anagen, the growth phase of the hair follicle, into catagen the apoptosis-induced regression phase. FGF5 interacts with fibroblast growth factor receptors, FGFR1 and FGFR2. Affinity between FGFs and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF-5 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTEKTGREWYVALNKRGKAKRGCSPRVKPQHISTHFLPRF 76
Cdd:cd23317   58 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASATHRNHRTGREWYVALNKRGKAKRGCSPRVKPQHISTHFLPRF 133

Acidic and basic fibroblast growth factor family; Mitogens that stimulate growth or differentiation of cells of mesodermal or neuroectodermal origin. The family play essential roles in patterning and differentiation during vertebrate embryogenesis, and have neurotrophic activities.

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 620597367     1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTektgrEWYVALNKRGKAKRGcsPRVKPQHISTHFLPR 75
Cdd:smart00442  59 MNKCGKLYGSKNFTEDCVFREEMEENGYNTYASAKYRK-----RWYVALNKKGRPRRG--QKTKPLQKASHFLPR 126

FGF domain, beta-trefoil fold, found in the fibroblast growth factor 9 (FGF9)-like family; The FGF9-like family includes FGF9, FGF16, and FGF20. FGF9, also called glia-activating factor (GAF), or heparin-binding growth factor 9 (HBGF-9), plays an important role in the regulation of embryonic development, cell proliferation, cell differentiation, and cell migration. It acts as a heparin-binding glia-activating factor that may have a role in glial cell growth and differentiation during development, gliosis during repair and regeneration of brain tissue after damage, differentiation and survival of neuronal cells, and growth stimulation of glial tumors. FGF9 interacts with fibroblast growth factor receptors, FGFR1, FGFR2, FGFR3, and FGFR4. FGF16 plays an important role in the regulation of embryonic development, cell proliferation and cell differentiation. It is required for normal cardiomyocyte proliferation and heart development. FGF16 interacts with FGFR1 and FGFR2. FGF20 acts as a neurotrophic factor that regulates central nervous development and function. It interacts with FGFR2 and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. Members in this family contain a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTEKTGREWYVALNKRGKAKRGCspRVKPQHISTHFLPR 75
Cdd:cd23308   57 MNEKGELYGSEKLTRECVFREQFEENWYNTYSSNLYKHADTGRRYYVALNKDGTPREGC--RTKRHQKFTHFLPR 129

FGF domain, beta-trefoil fold, found in fibroblast growth factor 20 (FGF20) and similar proteins; FGF20 acts as a neurotrophic factor that regulates central nervous development and function. It interacts with fibroblast growth factor receptors, FGFR2 and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF20 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTEKTGREWYVALNKRGKAKRGCspRVKPQHISTHFLPRFKQSE 80
Cdd:cd23327   66 MNDKGELYGSEKLTAECIFREQFEENWYNTYSSNLYKHGDTGRRYFVALNKDGTPRDGT--RSKRHQKFTHFLPRPVDPE 143

                 ....*
gi 620597367  81 Q-PEL 84
Cdd:cd23327  144 KvPEL 148

FGF domain, beta-trefoil fold, found in the fibroblast growth factor 7 (FGF7)-like family; The FGF7-like family includes FGF7, FGF10 and FGF22. FGF7, also called heparin-binding growth factor 7 (HBGF7), or keratinocyte growth factor (KGF), and FGF10 play important roles in the regulation of embryonic development, cell proliferation, and cell differentiation. They are required for normal branching morphogenesis. FGF7 is a growth factor active on keratinocytes. It may act as major paracrine effector of normal epithelial cell proliferation. FGF10 may play a role in wound healing. FGF22 plays a role in the fasting response, glucose homeostasis, lipolysis, and lipogenesis. It can stimulate cell proliferation (in vitro). It may be involved in hair development. FGF7 interacts with fibroblast growth factor receptor FGFR2 and fibroblast growth factor-binding protein 1 (FGFBP1). FGF10 and FGF22 interact with FGFR1, FGFR2 and FGFBP1. Members in this family contain a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAihRTEKTGREWYVALNKRGKAKRGcsPRVKPQHISTHFLPR 75
Cdd:cd23306   60 MNKKGKLYGKKDYNDDCRFKERIEENGYNTYASA--KWTHNGREMFVALSQKGRPLRG--KKTRRKNTAAHFLPM 130

FGF domain, beta-trefoil fold, found in fibroblast growth factor 16 (FGF16) and similar proteins; FGF16 plays an important role in the regulation of embryonic development, cell proliferation, and cell differentiation. It is required for normal cardiomyocyte proliferation and heart development. FGF16 interacts with fibroblast growth factor receptors, FGFR1 and FGFR2. FGF16 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTEKTGREWYVALNKRGKAKRGCspRVKPQHISTHFLPR 75
Cdd:cd23326   63 MNERGELYGSKKLTRECVFREQFEENWYNTYASTLYKHADSGRQYYVALNKDGSPREGY--RTKRHQKFTHFLPR 135

FGF domain, beta-trefoil fold, found in the fibroblast growth factor 11 (FGF11)-like family; The FGF11-like family includes FGF11-14. FGF11, also called fibroblast growth factor homologous factor 3 (FHF3), may be involved in nervous system development and function. It plays roles in angiogenesis, tumorigenesis, adipogenesis, or liver regeneration. FGF12, also called fibroblast growth factor homologous factor 1 (FHF1), or myocyte-activating factor, is involved in nervous system development and function. It plays a role in the positive regulation of voltage-gated sodium channel activity. It promotes neuronal excitability by elevating the voltage dependence of neuronal sodium channel SCN8A fast inactivation. FGF12 interacts with the C-terminal region of SCN9A. FGF13, also called Fibroblast growth factor homologous factor 2 (FHF2), is a microtubule-binding protein which directly binds tubulin and is involved in both polymerization and stabilization of microtubules. Through its action on microtubules, it may participate in the refinement of axons by negatively regulating axonal and leading processes branching. FGF13 plays a crucial role in neuron polarization and migration in the cerebral cortex and the hippocampus. It may regulate voltage-gated sodium channels transport and function. It may also play a role in MAPK signaling. It is required for the development of axonal initial segment-targeting inhibitory GABAergic synapses made by chandelier neurons. FGF13 interacts with SCN1A, SCN5A, and SCN8A. It may also interact with SCN2A and SCN11A. FGF14, also called fibroblast growth factor homologous factor 4 (FH-4), may be involved in nervous system development and function. It interacts with SCN8A. Members in this family contain a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTEKTGREWYVALNKRGKAKRGcsPRVKPQHISTHFLPR 75
Cdd:cd23309   58 MNSEGYLYTSEHFTPECKFKESVFENYYVIYSSMLYRQQQSGRAWYLGLNKEGQIMKG--NRVKKTKPAAHFLPK 130

FGF domain, beta-trefoil fold, found in the fibroblast growth factor 1 (FGF1)-like family; The FGF1-like family includes FGF1 and FGF2. FGF1, also called acidic fibroblast growth factor (aFGF), or endothelial cell growth factor (ECGF), or heparin-binding growth factor 1 (HBGF-1), plays an important role in the regulation of cell survival, cell division, angiogenesis, cell differentiation, and cell migration. It functions as a potent mitogen in vitro. FGF1 acts as a ligand for fibroblast growth factor receptor 1 (FGFR1) and integrin. It interacts with FGFR1, FGFR2, FGFR3, and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF1 also interacts with fibroblast growth factor-binding protein 1 (FGFBP1), FGF1, and FGF2. FGF2, also called basic fibroblast growth factor (bFGF), or heparin-binding growth factor 2 (HBGF2), acts as a ligand for FGFR1, FGFR2, FGFR3, and FGFR4. It also acts as an integrin ligand which is required for FGF2 signaling. FGF2 plays an important role in the regulation of cell survival, cell division, cell differentiation and cell migration. Both FGF1 and FGF2 contain a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHrtekTGREWYVALNKRGKAKRGcsPRVKPQHISTHFLPR 75
Cdd:cd23304   58 MNEDGRLYGSQTVNDECLFLERLEENHYNTYRSQKY----AEKNWYVGLKKNGRCKLG--PRTHYGQKAILFLPR 126

FGF domain, beta-trefoil fold, found in fibroblast growth factor 7 (FGF7) and similar proteins; FGF7, also called heparin-binding growth factor 7 (HBGF7), or keratinocyte growth factor (KGF), plays an important role in the regulation of embryonic development, cell proliferation, and cell differentiation. It is required for normal branching morphogenesis. It is a growth factor active on keratinocytes. It may act as major paracrine effector of normal epithelial cell proliferation. FGF7 interacts with fibroblast growth factor receptor FGFR2 and fibroblast growth factor-binding protein 1 (FGFBP1). Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF7 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHrTEKtGREWYVALNKRGKAKRGcsPRVKPQHISTHFLP 74
Cdd:cd23319   65 MNKEGKLYGKKVCNEDCNFKELIEENHYNTYASAKW-THK-GKEMFVALNQKGKPMKG--KKTKKEHKTSHFLP 134

FGF domain, beta-trefoil fold, found in fibroblast growth factor 4 (FGF4) and similar proteins; FGF4, also called heparin secretory-transforming protein 1 (HST-1), or HSTF-1, or heparin-binding growth factor 4 (HBGF4), or transforming protein KS3, plays an important role in the regulation of embryonic development, cell proliferation, and cell differentiation. It is required for normal limb and cardiac valve development during embryogenesis. It interacts with fibroblast growth factor receptors, FGFR1, FGFR2, FGFR3, and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF4 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTektgreWYVALNKRGKAKRGcsPRVKPQHISTHFLPR 75
Cdd:cd23316   58 MNSKGKLYGSPFFNDECKFKEILLPNNYNAYESRKYPG------MYIALSKNGKTKKG--NRVSPTMTVTHFLPR 124

FGF domain, beta-trefoil fold, found in fibroblast growth factor 3 (FGF3) and similar proteins; FGF3, also called heparin-binding growth factor 3 (HBGF3), or proto-oncogene Int-2, plays an important role in the regulation of embryonic development, cell proliferation, and cell differentiation. It is required for normal ear development. FGF3 interacts with fibroblast growth factor receptors, FGFR1 and FGFR2. Affinity between FGFs and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF3 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASAIHRTEKTG----------REWYVALNKRGKAKRGCSPRVKPQhiST 70
Cdd:cd23315   57 MNKRGRLYASEVYNAECEFVERIHELGYNTYASRLYRTVPSGagtkrkasaeRLWYVSINGKGRPRRGFKTRRTQK--SS 134

                 ....*
gi 620597367  71 HFLPR 75
Cdd:cd23315  135 LFLPR 139

FGF domain, beta-trefoil fold, found in fibroblast growth factor 2 (FGF2) and similar proteins; FGF2, also called basic fibroblast growth factor (bFGF), or heparin-binding growth factor 2 (HBGF2), acts as a ligand for fibroblast growth factor receptors, FGFR1, FGFR2, FGFR3, and FGFR4. It also acts as an integrin ligand which is required for FGF2 signaling. FGF2 plays an important role in the regulation of cell survival, cell division, cell differentiation, and cell migration. It functions as a potent mitogen in vitro. It can induce angiogenesis. FGF2 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 620597367   1 MSKKGKLHASAKFTDDCKFRERFQENSYNTYASaihrteKTGREWYVALNKRGKAKRGcsPRVKPQHISTHFLP 74
Cdd:cd23314   58 MKEDGRLLASKSVTDECFFFERLESNNYNTYRS------RKYTSWYVALKRTGQYKLG--SKTGPGQKAILFLP 123

FGF domain, beta-trefoil fold, found in the fibroblast growth factor 8 (FGF8)-like family; The FGF8-like family includes FGF8, FGF17 and FGF18. FGF8, also called androgen-induced growth factor (AIGF), or heparin-binding growth factor 8 (HBGF8), plays an important role in the regulation of embryonic development, cell proliferation, cell differentiation, and cell migration. It is required for normal brain, eye, ear,, and limb development during embryogenesis. It is also required for normal development of the gonadotropin-releasing hormone (GnRH) neuronal system. It plays a role in neurite outgrowth in hippocampal cells. FGF8 interacts with fibroblast growth factor receptors, FGFR1, FGFR2, FGFR3, and FGFR4. FGF17 plays an important role in the regulation of embryonic development and as signaling molecule in the induction and patterning of the embryonic brain. It is required for normal brain development. FGF17 interacts with FGFR3 and FGFR4. FGF18, also called zFGF5, plays an important role in the regulation of cell proliferation, cell differentiation, and cell migration. It is required for normal ossification and bone development. It stimulates hepatic and intestinal proliferation. FGF18 interacts FGFR3 and FGFR4. Members in this family contain a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 620597367   1 MSKKGKLHASAKFTDD--CKFRERFQENSYNTYASAIHRTektgreWYVALNKRGKAKRGcSPRVKPQHISTHFLPR 75
Cdd:cd23307   58 FNKKGKLVAKKNGKKDkrCVFEEELTDGYYTRYRSVKNPS------WYLGFNRNGRPLKG-SKTRKKKQKCFHFLKR 127

FGF domain, beta-trefoil fold, found in fibroblast growth factor 19 (FGF19) and similar proteins; FGF19 is involved in the suppression of bile acid biosynthesis through down-regulation of CYP7A1 expression, following positive regulation of the JNK and ERK1/2 cascades. It stimulates glucose uptake in adipocytes. Its activity requires the presence of beta-Klotho (KLB) and FGFR4. FGF-19 interacts with fibroblast growth factor receptors, FGFR1, FGFR2, FGFR3, and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by alpha-Klotho (KL), KLB and heparan sulfate glycosaminoglycans that function as coreceptors. FGF19 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 620597367   1 MSKKGKLHASAKFT-DDCKFRERFQENSYNTYASAIHRTektgrewYVALNkRGKAKRGCSPRVKPQHisTHFLPRF 76
Cdd:cd23331   62 MEADGKLYGSLSYSeEDCSFEEEILPDGYNVYRSKKHGL-------PVSLS-SAKQRQQYKDKGFLPL--SQFLPMI 128

FGF domain, beta-trefoil fold, found in fibroblast growth factor 8 (FGF8) and similar proteins; FGF8, also called androgen-induced growth factor (AIGF), or heparin-binding growth factor 8 (HBGF8), plays an important role in the regulation of embryonic development, cell proliferation, cell differentiation, and cell migration. It is required for normal brain, eye, ear, and limb development during embryogenesis. It is also required for normal development of the gonadotropin-releasing hormone (GnRH) neuronal system. It plays a role in neurite outgrowth in hippocampal cells. FGF8 interacts with fibroblast growth factor receptors, FGFR1, FGFR2, FGFR3, and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF8 contains a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 620597367   1 MSKKGKLHASAK-FTDDCKFRERFQENSYntyaSAIHRTEKTGreWYVALNKRGKAKRGCSPRVKPQHIstHFLPRF 76
Cdd:cd23322   79 MNKKGKLIGKSNgKGKDCVFTEIVLENNY----TALQNAKYEG--WYMAFTRKGRPRKGSKTRQHQREV--HFMKRL 147