Aug 2026· Proceedings of the National Academy of Sciences of the United States of America· Vol 123 34, pp.
e2533429123
· 0 citations· 40 references
Medicine
TL;DR
A metazoan-conserved dual degradation inhibition cascade whereby energy stress coordinates acetylation-phosphorylation crosstalk that simultaneously enhances glycolytic output and suppresses two protein degradation systems is reported.
Abstract
Cells reprogram glycolysis pathway to cope with energy deficiency, in which the catalytic activity, stability, and noncanonical functions of glycolytic enzymes are finely regulated by posttranslational modifications (PTMs). Here, we report a metazoan-conserved dual degradation inhibition cascade whereby energy stress coordinates acetylation-phosphorylation crosstalk that simultaneously enhances glycolytic output and suppresses two protein degradation systems. Specifically, KAT2 (KAT2A)/HDACIIa (HDAC5)-mediated acetylation of PGK at K73 (PGK1; K75) antagonizes its ubiquitin-proteasomal degradation while strengthening its interaction with ALDO (ALDOA). Then, PGK exerts noncanonical kinase activity to phosphorylate ALDO at S272, thereby enhancing ALDO's substrate affinity and suppressing its chaperone-mediated autophagic-lysosomal degradation by inhibiting the interaction with HSC70 to simultaneously stabilize and activate ALDO to amplify glycolytic flux. This ancient survival axis underlies thermotolerance divergence in oysters and is hijacked in human lung adenocarcinoma to drive malignant proliferation. Our study integrates environmental adaptation and tumorigenesis through a unified metabolic signaling axis, broadening our understanding of PTM crosstalk in evolution and disease.
This work integrates thermal proteome profiling with co-aggregation analysis to monitor protein thermal stability and complex assembly dynamics in response to two canonical inducers: Torin 1, which activates autophagy via mTOR inhibition, and CCCP, a mitochondrial uncoupler that triggers mitophagy.
Shuang Zhang, Ya Zeng, Feng-Ming Li et al.· Cell Communication and Signa...· 0 citations
Upon exposure to stress, cells activate a variety of stress-response and quality-control mechanisms to maintain homeostasis. Dysregulation of these processes is implicated in numerous diseases, including cancer, liver disorders, and neurodegenerative diseases. p62/Sequestosome 1 (SQSTM1) is a multifunctional protein that plays a central role in protein homeostasis and stress responses by regulating autophagy and signal transduction pathways. Through its multiple protein-interacting domains, p62 functions both as a scaffold for selective autophagic degradation and as a signaling hub. Since our previous review of p62 a decade ago, substantial progress has been made in elucidating its molecular functions and physiological roles. Notably, p62 undergoes liquid-liquid phase separation with ubiquitinated proteins to form membraneless condensates, termed p62 bodies, when cells are exposed to proteotoxic stress. By sequestering specific proteins, p62 bodies act as platforms for autophagy-dependent degradation and stress signaling. These findings have substantially revised our view of p62 function, which was previously considered primarily as a receptor simply linking ubiquitinated substrates to autophagic membranes and connecting signaling molecules. This conceptual shift from one-to-one molecular interactions to multivalent, multimolecular, higher-order assemblies has fundamentally redefined the functional landscape of p62. In this review, we highlight how p62 bodies integrate selective autophagy and stress signaling, with a particular emphasis on their emerging roles in disease pathogenesis and their potential as therapeutic targets.
Jun-ichi Sakamaki, Masaaki Komatsu· The FEBS Journal· 0 citations
Clear cell renal cell carcinoma (ccRCC) is characterized by profound metabolic dysregulation, with both prolyl hydroxylase domain protein 3 (PHD3) and pyruvate carboxylase (PC) independently implicated in disease progression. Although each influences patient outcomes, a direct mechanistic interplay between these two regulators has remained elusive. Here, we uncover a novel regulatory axis involving PHD3 and PC by identifying an unexpected subcellular behavior of PHD3, namely, its dual localization to the cytosol and the mitochondrial matrix. We show that mitochondrial import of PHD3 is associated with its intracellular clustering, a process modulated by PHD3 hydroxylase activity and oxygen levels. Once in the matrix, PHD3 directly hydroxylates PC, suppressing its enzymatic activity. In ccRCC with elevated PHD3 expression, this modification restricts anaplerotic flux into the tricarboxylic acid cycle, leading to impaired proliferation, reduced metastasis, and enhanced apoptosis. Together, our findings provide a new framework for targeting cancer metabolism by establishing a previously unrecognized mechanistic link between PHD3-mediated oxygen sensing within the tumor microenvironment and the regulation of ccRCC mitochondrial metabolism through the subcellular re-localization of PHD3.
Jaelim Sim, Soyeon Lim, Chang-Jun Lee et al.· Experimental and Molecular M...· 0 citations
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