Dahl, S. O. | Search bioRxiv

bioRxiv2026

Mapping the GCK-GKRP interaction landscape using deep mutational scanning by reverse two-hybrid screening

Glucokinase (GCK) regulates insulin secretion in the pancreas and glycogen synthesis in the liver. The best characterized interaction partner of GCK is the glucokinase regulatory protein (GKRP). GKRP is expressed in the liver where it regulates GCK activity and abundance. In this study, we used a library of GCK single amino acid substitutions and a reverse two-hybrid screen to characterize the impact of GCK variants on GKRP interaction. We obtained interaction scores for 7534 GCK single amino acid substitutions. A major driver of loss of interaction appeared to be loss of protein abundance, and we therefore compared interaction scores with our previously obtained GCK abundance scores to disentangle variant effects on interaction and abundance. Variants specifically perturbing interactions were found at the interaction interface but also structurally far from GKRP, revealing potential allosteric effects. In addition, unstable variants at buried residues in the large domain were stabilized by GKRP. These variants could potentially also be stabilized by e.g. pharmacological chaperones to rescue GCK function. In conclusion, we have now characterized the activity, abundance and interaction of 7128 GCK variants. Collectively these scores help pinpoint variants solely perturbing GKRP interaction, giving rise to liver-specific effects and potentially subtle glucose homeostasis phenotypes.

biochemistry↗

bioRxiv2025

Stone Age anthropogenic impacts to forest development in the interior Scandinavian Peninsula

Forest growth and development is a highly studied phenomenon in which humans have proven to be influential in shaping structure and composition. Delineating the long-term processes of human-environment interactions is crucial for understanding the history and trajectory of landscape formation and vegetation development. Yet, extensive knowledge of the ecological impacts of Stone Age anthropogenic activity is still lacking, particularly from Fennoscandian sites. A sediment core from South Mesna lake from the interior Scandinavian Peninsula was extracted to investigate the long-term evolutionary effects of human-environment interactions following deglaciation (c. 10,500 cal. BP) and initial colonization of the region. Analysis of the core involved microscopic/trace analytical methods, including geochemical analysis, stable isotope analysis, fecal biomarker analysis, and pollen analysis. The combined evidence demonstrates that anthropogenic impacts are prominent shapers of the ecological trajectory and landscape development of the region since the Early Neolithic (c. 5900 cal. BP), which has left a footprint on modern-day land cover. SignificanceAnthropogenic impacts on the environment have been observed to have had notable consequences on global and regional ecological trajectories and environmental development. Yet, how coupled human-environment interactions affect the long-term ecological complexion of boreal landscapes, such as those of the interior Scandinavian Peninsula, is not widely studied. This article presents evidence of early anthropogenic impacts to a forests ecology during the Holocene. Fecal biomarker and pollen analyses make it possible to provide micro-archaeological evidence of human activity and correlate it with noteworthy changes in forest structure. Our data points to a specific co-evolutionary forest development trajectory which is connected to millennial-scale human settlement patterns.

ecology↗