Introduction
The fibroblast growth factor (FGF) family consists of at least 18 structurally related proteins with diverse roles in physiological and pathological processes, including cell growth, differentiation, angiogenesis, wound healing, and tumor development. These proteins exert their biological effects by binding to and activating a family of type I transmembrane tyrosine kinase receptors known as FGF receptors (FGFRs). Upon ligand binding, FGFRs dimerize and undergo autophosphorylation, initiating downstream signaling cascades. Currently, four distinct genes encoding highly similar FGFRs (FGFR1-4) have been identified. All four FGFR genes encode proteins with a conserved structure, comprising an N-terminal signal peptide, three immunoglobulin (Ig)-like domains, an acidic region located between IgI and IgII domains, a transmembrane domain, and a split tyrosine kinase domain. Alternative splicing of FGFR1-3 mRNAs results in the generation of multiple receptor isoforms. Notably, a common splicing event affects both FGFR1 and FGFR2, producing two major isoforms: the 'a' isoform containing all three Ig domains, and the 'b' isoform lacking the IgI domain. In contrast, only the 'a' isoform has been reported for FGFR3 and FGFR4. Further splicing events observed in FGFR1-3 involve the C-terminal half of the IgIII domain, which is encoded by two mutually exclusive exons, resulting in receptors with variant IgIII domains (IIIb and IIIc). Moreover, a secreted FGFR1 isoform, designated IIIa, has been described, containing only the N-terminal half of the IgIII domain and some intronic sequences; this isoform acts as an FGF-binding protein. Mutations in FGFR1-3 have been linked to craniosynostosis, a group of birth defects characterized by premature skull suture fusion. Research continues to unravel the intricate expression patterns of these receptors and the specificity of their interactions with different FGF ligands.
Description
Recombinant Human Fibroblast Growth Factor Receptor-4, expressed in Sf9 Baculovirus cells, is a single glycosylated polypeptide chain with a molecular weight of 39.5 kDa (containing 356 amino acids, spanning residues 22-369a.a.). However, it appears as a band with an apparent molecular weight of 40-57 kDa on SDS-PAGE. This discrepancy can be attributed to glycosylation. This protein is fused with an 8 amino acid His tag at the C-terminus and purified using proprietary chromatographic techniques.
Physical Appearance
A clear, colorless solution that has been sterilized by filtration.
Formulation
The FGFR4 protein solution is provided at a concentration of 0.25 mg/ml in a buffer consisting of Phosphate Buffered Saline (pH 7.4) and 10% glycerol.
Stability
For short-term storage (up to 2-4 weeks), the protein should be stored at 4°C. For extended storage, it is recommended to freeze the protein at -20°C. To ensure long-term stability during frozen storage, it is advisable to add a carrier protein such as HSA or BSA to a final concentration of 0.1%. Repeated freezing and thawing of the protein should be avoided.
Purity
The purity of the protein is greater than 90.0% as determined by SDS-PAGE analysis.
Synonyms
Fibroblast Growth Factor Receptor 4, EC 2.7.10.1, JTK2, TKF, Tyrosine Kinase Related To Fibroblast Growth Factor Receptor, Hydroxyaryl-Protein Kinase, Protein-Tyrosine Kinase, Tyrosylprotein Kinase, CD334 Antigen, EC 2.7.10, FGFR-4, CD334, FGFR4.
Source
Sf9,
Baculovirus cells.
Amino Acid Sequence
LEASEEVELE PCLAPSLEQQ EQELTVALGQ PVRLCCGRAE RGGHWYKEGS RLAPAGRVRG WRGRLEIASF LPEDAGRYLC LARGSMIVLQ NLTLITGDSL TSSNDDEDPK SHRDPSNRHS YPQQAPYWTH PQRMEKKLHA VPAGNTVKFR CPAAGNPTPT IRWLKDGQAF HGENRIGGIR LRHQHWSLVM ESVVPSDRGT YTCLVENAVG SIRYNYLLDV LERSPHRPIL QAGLPANTTA VVGSDVELLC KVYSDAQPHI QWLKHIVING SSFGADGFPY VQVLKTADIN SSEVEVLYLR NVSAEDAGEY TCLAGNSIGL SYQSAWLTVL PEEDPTWTAA APEARYTDLE HHHHHH.
