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Phenotypic Selection with an Intrabody Library Reveals an Anti-apoptotic Function of PKM2 Requiring Mitofusin-1

Overview
Journal PLoS Biol
Specialty Biology
Date 2019 Jun 11
PMID 31181072
Citations 8
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Abstract

Bcl-2 family proteins control a decisive apoptotic event: mitochondrial outer membrane permeabilization (MOMP). To discover MOMP-regulating proteins, we expressed a library of intracellular single-chain variable fragments (scFvs) ("intrabodies") and selected for those rescuing cells from apoptosis induced by BimS (the short isoform of Bim). One anti-apoptotic intrabody, intrabody 5 (IB5), recognized pyruvate kinase M2 (PKM2), which is expressed in cancer cells. PKM2 deletion ablated this clonogenic rescue; thus, IB5 activated a latent cytoprotective function of PKM2. This resulted not from pyruvate kinase activity per se but rather from the formation of an active tetrameric conformation of PKM2. A stably tetrameric PKM2 mutant, K422R, promoted cell survival even in the absence of IB5, and IB5 further increased survival. Mitochondria isolated from IB5-expressing cells were relatively resistant to MOMP in vitro. In cells, IB5 expression up-regulated Mitofusin-1 (Mfn1) and increased mitochondrial length. Importantly, Mfn1 deficiency abrogated IB5's cytoprotective effect. PKM2's anti-apoptotic function could help explain its preferential expression in human cancer.

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References
1.
Bollenbach T, Mesecar A, Nowak T . Role of lysine 240 in the mechanism of yeast pyruvate kinase catalysis. Biochemistry. 1999; 38(28):9137-45. DOI: 10.1021/bi990690n. View

2.
Choudhary V, Kaddour-Djebbar I, Alaisami R, Kumar M, Bollag W . Mitofusin 1 degradation is induced by a disruptor of mitochondrial calcium homeostasis, CGP37157: a role in apoptosis in prostate cancer cells. Int J Oncol. 2014; 44(5):1767-73. DOI: 10.3892/ijo.2014.2343. View

3.
Gillies L, Du H, Peters B, Knudson C, Newmeyer D, Kuwana T . Visual and functional demonstration of growing Bax-induced pores in mitochondrial outer membranes. Mol Biol Cell. 2014; 26(2):339-49. PMC: 4294680. DOI: 10.1091/mbc.E13-11-0638. View

4.
Kwon O, Kang T, Kim J, Kim M, Noh S, Song K . Pyruvate kinase M2 promotes the growth of gastric cancer cells via regulation of Bcl-xL expression at transcriptional level. Biochem Biophys Res Commun. 2012; 423(1):38-44. DOI: 10.1016/j.bbrc.2012.05.063. View

5.
Chen L, Willis S, Wei A, Smith B, Fletcher J, Hinds M . Differential targeting of prosurvival Bcl-2 proteins by their BH3-only ligands allows complementary apoptotic function. Mol Cell. 2005; 17(3):393-403. DOI: 10.1016/j.molcel.2004.12.030. View