Structural highlights
Disease
PYC_HUMAN Defects in PC are the cause of pyruvate carboxylase deficiency (PC deficiency) [MIM:266150. PC deficiency leads to lactic acidosis, mental retardation and death. It occurs in three forms: mild or type A, severe neonatal or type B, and a very mild lacticacidemia.
Function
PYC_HUMAN Pyruvate carboxylase catalyzes a 2-step reaction, involving the ATP-dependent carboxylation of the covalently attached biotin in the first step and the transfer of the carboxyl group to pyruvate in the second. Catalyzes in a tissue specific manner, the initial reactions of glucose (liver, kidney) and lipid (adipose tissue, liver, brain) synthesis from pyruvate.
Publication Abstract from PubMed
Pyruvate carboxylase (PC) catalyzes the two-step carboxylation of pyruvate to produce oxaloacetate, playing a key role in the maintenance of metabolic homeostasis in cells. Given its involvement in multiple diseases, PC has been regarded as a potential therapeutic target for obesity, diabetes, and cancer. Albeit acetyl-CoA has been recognized as the allosteric regulator of PC for over 60 years, the underlying mechanism of how acetyl-CoA induces PC activation remains enigmatic. Herein, by using time-resolved cryo-electron microscopy, we have captured the snapshots of PC transitional states during its catalytic cycle. These structures and the biochemical studies reveal that acetyl-CoA stabilizes PC in a catalytically competent conformation, which triggers a cascade of events, including ATP hydrolysis and the long-distance communication between the two reactive centers. These findings provide an integrated picture for PC catalysis and unveil the unique allosteric mechanism of acetyl-CoA in an essential biochemical reaction in all kingdoms of life.
Mechanistic insight into allosteric activation of human pyruvate carboxylase by acetyl-CoA.,Chai P, Lan P, Li S, Yao D, Chang C, Cao M, Shen Y, Ge S, Wu J, Lei M, Fan X Mol Cell. 2022 Nov 3;82(21):4116-4130.e6. doi: 10.1016/j.molcel.2022.09.033. Epub, 2022 Oct 24. PMID:36283412[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Chai P, Lan P, Li S, Yao D, Chang C, Cao M, Shen Y, Ge S, Wu J, Lei M, Fan X. Mechanistic insight into allosteric activation of human pyruvate carboxylase by acetyl-CoA. Mol Cell. 2022 Nov 3;82(21):4116-4130.e6. doi: 10.1016/j.molcel.2022.09.033. Epub, 2022 Oct 24. PMID:36283412 doi:http://dx.doi.org/10.1016/j.molcel.2022.09.033
