Protein Stability, Folding and Misfolding in Human PGK1 Deficiency

Abstract

Conformational diseases are often caused by mutations, altering protein folding and stability in vivo. We review here our recent work on the effects of mutations on the human phosphoglycerate kinase 1 (hPGK1), with a particular focus on thermodynamics and kinetics of protein folding and misfolding. Expression analyses and in vitro biophysical studies indicate that disease-causing mutations enhance protein aggregation propensity. We found a strong correlation among protein aggregation propensity, thermodynamic stability, cooperativity and dynamics. Comparison of folding and unfolding properties with previous reports in PGKs from other species suggests that hPGK1 is very sensitive to mutations leading to enhance protein aggregation through changes in protein folding cooperativity and the structure of the relevant denaturation transition state for aggregation. Overall, we provide a mechanistic framework for protein misfolding of hPGK1, which is insightful to develop new therapeutic strategies aimed to target native state stability and foldability in hPGK1 deficient patients.

Insights into human phosphoglycerate kinase 1 deficiency as a conformational disease from biochemical, biophysical, and in vitro expression analyses

“…Genotype-phenotype correlations in hPGK1 deficiency can be drawn quite univocally only for a few mutations, especially those causing heavily impaired protein stability but mildly affecting catalytic efficiency. This type of mutation in hPGK1 deficiency correlates with hemolytic anemia and neurological disorders but (in general) no myopathy Valentini et al 2013). Interestingly, we show here that mutants in this group (p.I47N, p.L89P, p.C316R, p.S320N, and p.A354P; (Maeda and Yoshida 1991;Maeda et al 1992;M o r i m o t oe ta l .2003;N o e le ta l .2006) display the highest sensitivity toward aggregation (in vitro and inside cells) and proteolysis, indicating that reduced nativestate stability and altered protein dynamics may be resposible for hPGK1 loss of function in vivo for carriers of mutations belonging to this group.…”

“…PGK exists in humans as two isoforms (hPGK1 and hPGK2), which are functionally and structurally similar monomeric proteins (Willard et al 1985;McCarrey and Thomas 1987;Cliff et al 2010). Human phosphoglycerate kinase 1 (hPGK1) deficiency (OMIM ID 311800) is a rare, inherited disease caused by mutations in the PGK1 gene, which is characterized by pleomorphic clinical presentation involving myopathy, neurological disfunctions, and nonspherocytic hemolytic anemia [see (Beutler 2007;Chiarelli et al 2012;Valentini et al 2013) for further details]. Only a few hPGK1deficient patients exhibit all three cardinal features of the disease, and several cases of hPGK-1 deficiency with myopathy in the absence of hemolytic anemia have been reported (Beutler 2007;Chiarelli et al 2012;Valentini et al 2013).…”

“…Human phosphoglycerate kinase 1 (hPGK1) deficiency (OMIM ID 311800) is a rare, inherited disease caused by mutations in the PGK1 gene, which is characterized by pleomorphic clinical presentation involving myopathy, neurological disfunctions, and nonspherocytic hemolytic anemia [see (Beutler 2007;Chiarelli et al 2012;Valentini et al 2013) for further details]. Only a few hPGK1deficient patients exhibit all three cardinal features of the disease, and several cases of hPGK-1 deficiency with myopathy in the absence of hemolytic anemia have been reported (Beutler 2007;Chiarelli et al 2012;Valentini et al 2013). hPGK1 is expressed in all somatic and premeiotic cells, with a primary sequence 417 amino acids long and a molecular weight of ∼45 kDa.…”

PGK1 Drives Hepatocellular Carcinoma Metastasis by Enhancing Metabolic Process

“…On the other side, the structure of human PGK1 (hPGK1) has been well understood. hPGK1, as long as 417 amino acids, is a typical hinge-bending enzyme with two similar sized Rossmann fold domains [ 17 ]. When the two substrates are bonded, the hinge flexion moves the enzyme into a closed form to allow the substrate to contact [ 17 ].…”

Analysis of interactions between potent inhibitors of ATP sulfurylase via molecular dynamics

“…The enzyme can adopt different conformational states and transition between these states can be triggered by ligand binding. [22] After 7.8 ns, it undergoes other transitions and it becomes stable around 20 ns (0.38 nm). These data indicate that the system passes through several different unfolding and folding states.…”