SUMOylation disassembles the tetrameric pyruvate kinase M2 to block myeloid differentiation of leukemia cells

Li Xia,Xue-Hong Zhang,Ying Lu,Yue Jiang,Kang Qin,Ran Wei,Xin-Ran Wang

doi:10.1038/s41419-021-03400-9

Abstract

Leukemia arises from blockage of the differentiation/maturation of hematopoietic progenitor cells at different stages with uncontrolled proliferation of leukemic cells. However, the signal pathways that block cell differentiation remain unclear. Herein we found that SUMOylation of the M2 isoform of pyruvate kinase (PKM2), a rate-limiting glycolytic enzyme catalyzing the dephosphorylation of phosphoenolpyruvate to pyruvate, is prevalent in a variety of leukemic cell lines as well as primary samples from patients with leukemia through multiple-reaction monitoring based targeted mass spectrometry analysis. SUMOylation of PKM2 lysine 270 (K270) triggered conformation change from tetrameric to dimeric of PKM2, reduced PK activity, and led to nuclear translocation of PKM2. SUMO1 modification of PKM2 recruits and promotes degradation of RUNX1 via a SUMO-interacting motif, resulting in blockage of myeloid differentiation of NB4 and U937 leukemia cells. Replacement of wild type PKM2 with a SUMOylation-deficient mutant (K270R) abrogated the interaction with RUNX1, and the blockage of myeloid differentiation in vitro and in xenograft model. Our results establish PKM2 as an essential modulator of leukemia cell differentiation and a potential therapeutic target, which may offer synergistic effect with differentiation therapy in the treatment of leukemia.

Highlights

The pyruvate kinase (PK) is a rate-limiting glycolytic enzyme catalyzing the dephosphorylation of phosphoenolpyruvate to pyruvate, yielding one molecule of ATP
The result showed that antiFlag antibody greatly enriched a band with a size of Mr ~95 kDa, which could be strongly detected by anti-SUMO1 antibody (Fig. 1A)
Endogenous SUMOylated-PKM2 could be detected in a number of leukemia cell lines (Fig. 1D) as well as primary bone marrow mononuclear cells (BMMC) samples from acute myeloid leukemia (AML) or chronic myeloid leukemia (CML) patients (Fig. 1E) but not adherent cell lines (Fig. 1F)

Summary

Introduction

The pyruvate kinase (PK) is a rate-limiting glycolytic enzyme catalyzing the dephosphorylation of phosphoenolpyruvate to pyruvate, yielding one molecule of ATP. PKM1 is expressed in normal adult tissues that require high levels of energy, such as the heart, brain, and skeletal muscle and constitutively forms stable tetramers (the active form of PK). PKM2, the dominant form of PK in tumors, exists in either tetramers. PKM2 endows tumor cells with growth advantage, and genomic instability through interacting with P53 and functioning as a protein kinase of histone H2AX10–12. Multiple post-translational modifications including acylation, phosphorylation, methylation, oxidation, and OGlcNAcylation of PKM2 have been identified to powerfully modulate its activity[13,14,15,16,17,18,19,20,21], which occur in response to various stimuli during tumor initiation or maintenance[13,17,20,22].

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