Identification of a depupylation regulator for an essential enzyme in Mycobacterium tuberculosis

• 成果类型: Article
• 署名作者: Kahne, Shoshanna C.; Yoo, Jin Hee; Chen, James; Nakedi, Kehilwe; Iyer, Lakshminarayan M.; Putzel, Gregory; Samhadaneh, Nora M.; Pironti, Alejandro; Aravind, L.; Ekiert, Damian C.; Bhabha, Gira; Rhee, Kyu Y.; Darwin, K. Heran
• 署名单位: New York University; Cornell University; Weill Cornell Medicine; National Institutes of Health (NIH) - USA; NIH National Library of Medicine (NLM); Johns Hopkins University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10854
• DOI: 10.1073/pnas.2407239121
• 发表日期: 2024-12-03
• 关键词: iii pantothenate kinase; particle cryo-em; structural basis; coenzyme-a; crystal-structure; protein pup; proteasome; PATHWAY; dop; transporter

摘要

In Mycobacterium tuberculosis (Mtb), proteins that are posttranslationally modified with a prokaryotic ubiquitin-like protein (Pup) can be degraded by bacterial proteasomes. A single Pup-ligase and depupylase shape the pupylome, but the mechanisms regulating their substrate specificity are incompletely understood. Here, we identified a depupylation regulator, a protein called CoaX, through its copurification with the depupylase Dop. CoaX is a pseudopantothenate kinase that showed evidence of binding to pantothenate, an essential nutrient Mtb synthesizes, but not its phosphorylation. In a Delta coaX mutant, pantothenate synthesis enzymes including PanB, a substrate of the Pup- proteasome system (PPS), were more abundant than in the parental strain. In vitro, CoaX specifically accelerated depupylation of Pup similar to PanB, while addition of pantothenate inhibited this reaction. In culture, media supplementation with pantothenate decreased PanB levels, which required CoaX. Collectively, we propose CoaX regulates PanB abundance in response to pantothenate levels by modulating its vulnerability to proteolysis by Mtb proteasomes.