6WP3

Pyruvate Kinase M2 Mutant-K433Q

6WP3 の概要

• エントリーDOI: 10.2210/pdb6wp3/pdb
• 分子名称: Pyruvate kinase PKM, GLYCEROL, OXALATE ION, ... (8 entities in total)
• 機能のキーワード: glycolysis, gene regulation, phosphotransferase, transferase
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 121165.96

構造登録者

Nandi, S.,Razzaghi, M.,Srivastava, D.,Dey, M. (登録日: 2020-04-26, 公開日: 2020-10-07, 最終更新日: 2023-10-18)

主引用文献

Nandi, S.,Razzaghi, M.,Srivastava, D.,Dey, M.
Structural basis for allosteric regulation of pyruvate kinase M2 by phosphorylation and acetylation.
J.Biol.Chem., 295:17425-17440, 2020

PubMed Abstract: Pyruvate kinase muscle isoform 2 (PKM2) is a key glycolytic enzyme and transcriptional coactivator and is critical for tumor metabolism. In cancer cells, native tetrameric PKM2 is phosphorylated or acetylated, which initiates a switch to a dimeric/monomeric form that translocates into the nucleus, causing oncogene transcription. However, it is not known how these post-translational modifications (PTMs) disrupt the oligomeric state of PKM2. We explored this question via crystallographic and biophysical analyses of PKM2 mutants containing residues that mimic phosphorylation and acetylation. We find that the PTMs elicit major structural reorganization of the fructose 1,6-bisphosphate (FBP), an allosteric activator, binding site, impacting the interaction with FBP and causing a disruption in oligomerization. To gain insight into how these modifications might cause unique outcomes in cancer cells, we examined the impact of increasing the intracellular pH (pH) from ∼7.1 (in normal cells) to ∼7.5 (in cancer cells). Biochemical studies of WT PKM2 (wtPKM2) and the two mimetic variants demonstrated that the activity decreases as the pH is increased from 7.0 to 8.0, and wtPKM2 is optimally active and amenable to FBP-mediated allosteric regulation at pH 7.5. However, the PTM mimetics exist as a mixture of tetramer and dimer, indicating that physiologically dimeric fraction is important and might be necessary for the modified PKM2 to translocate into the nucleus. Thus, our findings provide insight into how PTMs and pH regulate PKM2 and offer a broader understanding of its intricate allosteric regulation mechanism by phosphorylation or acetylation.

PubMed: 33453989
DOI: 10.1074/jbc.RA120.015800

実験手法

X-RAY DIFFRACTION (1.84 Å)