FGFR-4, a novel acidic fibroblast growth factor receptor with a distinct expression pattern

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• Two novel fibroblast growth factor receptor (FGFR) family members were previously identified in K562 erythroleukemia cells.
• Fibroblast growth factor receptors play crucial roles in cell signaling and development.

Purpose of the Study:

• To report the cDNA cloning and characterization of one novel FGFR member, designated FGFR-4.
• To investigate the structural, functional, and expression characteristics of FGFR-4.

Main Methods:

• cDNA cloning and sequence analysis of FGFR-4.
• Antibody-based detection of FGFR-4 protein in transfected COS cells.
• Ligand binding assays using acidic and basic FGF.
• mRNA expression analysis in human fetal tissues.

Main Results:

• FGFR-4 shares 55% amino acid identity with known FGFRs (flg, bek) and possesses characteristic FGFR structural domains.
• FGFR-4 protein (95 and 110 kd glycoproteins) was detected in transfected COS cells and binds acidic FGF with high affinity.
• FGFR-4 mRNA (3.0 kb) is expressed in various human fetal tissues, with a distinct pattern compared to other FGFRs.
• FGFR-4 does not bind basic FGF.

Conclusions:

• FGFR-4 is a novel member of the FGFR gene family with unique binding properties and tissue-specific expression.
• The distinct expression pattern suggests FGFR-4 plays specific cell lineage and tissue-dependent roles.
• FGFR-4 contributes to the diverse functions of fibroblast growth factor receptors in biological processes.