ESAT-6 undergoes self-association at phagosomal pH and an ESAT-6 specific nanobody restricts M. tuberculosis growth in macrophages.

Autor:	Bates TA; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Trank-Greene M; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Nguyenla X; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Anastas A; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Gurmessa SK; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Merutka IR; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Dixon SD; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Shumate A; Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon, United States., Groncki AR; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Parson MA; Department of Biochemistry and Microbiology, University of Victoria, Victoria, Canada., Ingram JR; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States., Barklis E; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States., Burke JE; Department of Biochemistry and Microbiology, University of Victoria, Victoria, Canada.; Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, Canada., Shinde U; Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon, United States., Ploegh HL; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States., Tafesse FG; Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, Portland, Oregon, United States.
Jazyk:	angličtina
Zdroj:	BioRxiv : the preprint server for biology [bioRxiv] 2024 Mar 19. Date of Electronic Publication: 2024 Mar 19.
DOI:	10.1101/2023.08.16.553641
Abstrakt:	Mycobacterium tuberculosis (Mtb) is known to survive within macrophages by compromising the integrity of the phagosomal compartment in which it resides. This activity primarily relies on the ESX-1 secretion system, predominantly involving the protein duo ESAT-6 and CFP-10. CFP-10 likely acts as a chaperone, while ESAT-6 likely disrupts phagosomal membrane stability via a largely unknown mechanism. we employ a series of biochemical analyses, protein modeling techniques, and a novel ESAT-6-specific nanobody to gain insight into the ESAT-6's mode of action. First, we measure the binding kinetics of the tight 1:1 complex formed by ESAT-6 and CFP-10 at neutral pH. Subsequently, we demonstrate a rapid self-association of ESAT-6 into large complexes under acidic conditions, leading to the identification of a stable tetrameric ESAT-6 species. Using molecular dynamics simulations, we pinpoint the most probable interaction interface. Furthermore, we show that cytoplasmic expression of an anti-ESAT-6 nanobody blocks Mtb replication, thereby underlining the pivotal role of ESAT-6 in intracellular survival. Together, these data suggest that ESAT-6 acts by a pH dependent mechanism to establish two-way communication between the cytoplasm and the Mtb-containing phagosome. Competing Interests: Competing interests HLP serves as an advisor to and owns stock in Cerberus Therapeutics. HLP serves as a consultant to Johnson and Johnson, Immatics Therapeutics, Cue Biopharma, Revela Therapeutics, and Tiba Bio. JEB reports personal fees from Scorpion Therapeutics, Reactive therapeutics and Olema Oncology; and research grants from Novartis. All other authors declare that they have no competing interests.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu