TY - JOUR

T1 - Characterizing glucokinase variant mechanisms using a multiplexed abundance assay

AU - Gersing, Sarah

AU - Schulze, Thea K.

AU - Cagiada, Matteo

AU - Stein, Amelie

AU - Roth, Frederick P.

AU - Lindorff-Larsen, Kresten

AU - Hartmann-Petersen, Rasmus

N1 - Publisher Copyright: © The Author(s) 2024.

PY - 2024

Y1 - 2024

N2 - Background: Amino acid substitutions can perturb protein activity in multiple ways. Understanding their mechanistic basis may pinpoint how residues contribute to protein function. Here, we characterize the mechanisms underlying variant effects in human glucokinase (GCK) variants, building on our previous comprehensive study on GCK variant activity. Results: Using a yeast growth-based assay, we score the abundance of 95% of GCK missense and nonsense variants. When combining the abundance scores with our previously determined activity scores, we find that 43% of hypoactive variants also decrease cellular protein abundance. The low-abundance variants are enriched in the large domain, while residues in the small domain are tolerant to mutations with respect to abundance. Instead, many variants in the small domain perturb GCK conformational dynamics which are essential for appropriate activity. Conclusions: In this study, we identify residues important for GCK metabolic stability and conformational dynamics. These residues could be targeted to modulate GCK activity, and thereby affect glucose homeostasis.

AB - Background: Amino acid substitutions can perturb protein activity in multiple ways. Understanding their mechanistic basis may pinpoint how residues contribute to protein function. Here, we characterize the mechanisms underlying variant effects in human glucokinase (GCK) variants, building on our previous comprehensive study on GCK variant activity. Results: Using a yeast growth-based assay, we score the abundance of 95% of GCK missense and nonsense variants. When combining the abundance scores with our previously determined activity scores, we find that 43% of hypoactive variants also decrease cellular protein abundance. The low-abundance variants are enriched in the large domain, while residues in the small domain are tolerant to mutations with respect to abundance. Instead, many variants in the small domain perturb GCK conformational dynamics which are essential for appropriate activity. Conclusions: In this study, we identify residues important for GCK metabolic stability and conformational dynamics. These residues could be targeted to modulate GCK activity, and thereby affect glucose homeostasis.

KW - DMS

KW - GCK

KW - MAVE

KW - Protein dynamics

KW - Protein stability

U2 - 10.1186/s13059-024-03238-2

DO - 10.1186/s13059-024-03238-2

M3 - Journal article

C2 - 38627865

AN - SCOPUS:85190668382

VL - 25

JO - Genome Biology (Online Edition)

JF - Genome Biology (Online Edition)

SN - 1474-7596

IS - 1

M1 - 98

ER -