Fibroblast growth factors (FGFs) are crucial for various cellular functions, including proliferation, differentiation, tissue repair, and immune responses. FGF10, part of the FGF7 subfamily, binds to the FGFR2b receptor via heparin sulfate. We determined the crystal structure of human FGF10 alone. In the FGFR2b-bound form, the N-terminal region of FGF10 formed an α1 helix. This α1 helix, however, exists as a flexible loop with dual conformations in the unbound structure. Deleting this conformationally dynamic α1 helix reduces cell proliferation activity in vitro. Receptor-binding-induced formation of the α1 helix in FGF10 creates a distinct protruded knob and concave pocket on the globular core of FGFs, increasing the FGFR2b-binding surface by 37%. Size-exclusion chromatography showed a concentration-dependent dimer-monomer shift in purified FGF10, with the hydrophobic dimer interface aligning with the FGFR2b D2-domain-binding surface. These findings suggest that the conformational change in the N-terminal region and the dimer-monomer shift are critical for FGF10's specific binding to FGFR2b, highlighting the functional significance of these structural adaptations.

A plant species has historically experienced repeated cycles of habitat connectivity and isolation, which have played a crucial role in increasing genetic diversity and promoting long-term survival. Therefore, understanding these dynamics is essential for developing effective conservation strategies. Thuja koraiensis is an endangered coniferous shrub inhabiting the mountain summits of the Baekdudaegan, a critical ecological axis in northeastern Asia. We used a genome dataset (242 SNPs) generated by the MIG-seq (Multiplexed ISSR Genotyping by Sequencing) method to evaluate the genetic diversity and structure of T. koraiensis populations across their entire distribution range. T. koraiensis exhibited a population history, with range expansion during glacial periods and contraction during interglacial periods. During the Last Glacial Maximum (LGM), genetic connectivity among populations was high, but post-LGM habitat fragmentation led to increasing isolation. This shift resulted in a rapid decline in effective population size and severe bottlenecks across all populations. Consequently, the genetic variation in current populations exhibits a geographically random pattern. Nevertheless, no signs of inbreeding or significant imbalances in genetic diversity were detected among populations. Therefore, we propose that conservation strategies should not solely focus on increasing genetic diversity or enhancing gene flow among populations but rather reflect the species’ historical demographic dynamics and aim to conserve the unique genetic characteristics of each population.