Open AccessDistinct Mycobacterium marinum phosphatases determine pathogen vacuole phosphoinositide pattern, phagosome maturation, and escape to the cytosol
Author(s) -
KoliwerBrandl Hendrik,
Knobloch Paulina,
Barisch Caroline,
Welin Amanda,
Hanbil,
Soldati Thierry,
Hilbi Hubert
Publication year - 2019
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/cmi.13008
Subject(s) - mycobacterium marinum , biology , vacuole , phagosome , phosphatase , microbiology and biotechnology , mycobacterium , cytoplasm , bacteria , phagocytosis , genetics , phosphorylation
The causative agent of tuberculosis, Mycobacterium tuberculosis , and its close relative Mycobacterium marinum manipulate phagocytic host cells, thereby creating a replication‐permissive compartment termed the Mycobacterium ‐containing vacuole (MCV). The phosphoinositide (PI) lipid pattern is a crucial determinant of MCV formation and is targeted by mycobacterial PI phosphatases. In this study, we establish an efficient phage transduction protocol to construct defined M . marinum deletion mutants lacking one or three phosphatases, PtpA, PtpB, and/or SapM. These strains were defective for intracellular replication in macrophages and amoebae, and the growth defect was complemented by the corresponding plasmid‐borne genes. Fluorescence microscopy of M . marinum ‐infected Dictyostelium discoideum revealed that MCVs harbouring mycobacteria lacking PtpA, SapM, or all three phosphatases accumulate significantly more phosphatidylinositol‐3‐phosphate (PtdIns3 P ) compared with MCVs containing the parental strain. Moreover, PtpA reduced MCV acidification by blocking the recruitment of the V‐ATPase, and all three phosphatases promoted bacterial escape from the pathogen vacuole to the cytoplasm. In summary, the secreted M . marinum phosphatases PtpA, PtpB, and SapM determine the MCV PI pattern, compartment acidification, and phagosomal escape.