S100A13-C2A binary complex structure-a key component in the acidic fibroblast growth factor for the non-classical...

Area of Science:

• Molecular Biology
• Biochemistry
• Cell Biology

Background:

• Fibroblast growth factors (FGFs) regulate critical cellular processes including proliferation, differentiation, and angiogenesis.
• FGFs signal through fibroblast growth factor receptors (FGFRs) and require extracellular release, typically via classical secretion pathways.
• FGF-1 lacks a signal peptide, necessitating a non-classical export mechanism.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying the non-classical release of FGF-1.
• To characterize the structure and function of the multiprotein complex involved in FGF-1 release.
• To investigate the role of S100A13 and synaptotagmin 1 in FGF-1 export.

Main Methods:

• Nuclear Magnetic Resonance (NMR) spectroscopy, including (1)H-(15)N HSQC titration and 3D-filtered NOESY experiments.
• Characterization of the binary complex structure of S100A13 and the C2A domain of synaptotagmin 1 (Syt1).
• Analysis of protein-protein interactions within the FGF-1 release complex.

Main Results:

• The binary complex structure of S100A13-C2A was determined using multi-dimensional NMR.
• This S100A13-C2A complex serves as a template for FGF-1 dimerization.
• The complex facilitates the formation of a larger multiprotein complex essential for FGF-1 release.

Conclusions:

• FGF-1 release occurs through a non-classical pathway mediated by a multiprotein complex.
• The S100A13-C2A complex is a key structural component that enables FGF-1 release.
• Understanding this pathway provides insights into FGF-1 regulation in development and disease.