PMID- 31543504 OWN - NLM STAT- MEDLINE DCOM- 20200608 LR - 20210205 IS - 1083-351X (Electronic) IS - 0021-9258 (Print) IS - 0021-9258 (Linking) VI - 294 IP - 45 DP - 2019 Nov 8 TI - The myotubularin MTMR4 regulates phagosomal phosphatidylinositol 3-phosphate turnover and phagocytosis. PG - 16684-16697 LID - 10.1074/jbc.RA119.009133 [doi] AB - Macrophage phagocytosis is required for effective clearance of invading bacteria and other microbes. Coordinated phosphoinositide signaling is critical both for phagocytic particle engulfment and subsequent phagosomal maturation to a degradative organelle. Phosphatidylinositol 3-phosphate (PtdIns(3)P) is a phosphoinositide that is rapidly synthesized and degraded on phagosomal membranes, where it recruits FYVE domain- and PX motif-containing proteins that promote phagosomal maturation. However, the molecular mechanisms that regulate PtdIns(3)P removal from the phagosome have remained unclear. We report here that a myotubularin PtdIns(3)P 3-phosphatase, myotubularin-related protein-4 (MTMR4), regulates macrophage phagocytosis. MTMR4 overexpression reduced and siRNA-mediated Mtmr4 silencing increased levels of cell-surface immunoglobulin receptors (i.e. Fcgamma receptors (FcgammaRs)) on RAW 264.7 macrophages, associated with altered pseudopodal F-actin. Furthermore, MTMR4 negatively regulated the phagocytosis of IgG-opsonized particles, indicating that MTMR4 inhibits FcgammaR-mediated phagocytosis, and was dynamically recruited to phagosomes of macrophages during phagocytosis. MTMR4 overexpression decreased and Mtmr4-specific siRNA expression increased the duration of PtdIns(3)P on phagosomal membranes. Macrophages treated with Mtmr4-specific siRNA were more resistant to Mycobacterium marinum-induced phagosome arrest, associated with increased maturation of mycobacterial phagosomes, indicating that extended PtdIns(3)P signaling on phagosomes in the Mtmr4-knockdown cells permitted trafficking of phagosomes to acidic late endosomal and lysosomal compartments. In conclusion, our findings indicate that MTMR4 regulates PtdIns(3)P degradation in macrophages and thereby controls phagocytosis and phagosomal maturation. CI - (c) 2019 Sheffield et al. FAU - Sheffield, David A AU - Sheffield DA AD - Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. AD - Department of Microbiology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. FAU - Jepsen, Malene R AU - Jepsen MR AD - Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. FAU - Feeney, Sandra J AU - Feeney SJ AD - Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. FAU - Bertucci, Micka C AU - Bertucci MC AD - Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. FAU - Sriratana, Absorn AU - Sriratana A AD - Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. FAU - Naughtin, Monica J AU - Naughtin MJ AD - Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. FAU - Dyson, Jennifer M AU - Dyson JM AD - Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. FAU - Coppel, Ross L AU - Coppel RL AD - Department of Microbiology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. FAU - Mitchell, Christina A AU - Mitchell CA AD - Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia Christina.mitchell@monash.edu. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20190922 PL - United States TA - J Biol Chem JT - The Journal of biological chemistry JID - 2985121R RN - 0 (Actins) RN - 0 (Immunoglobulin G) RN - 0 (Phosphatidylinositol Phosphates) RN - 0 (RNA, Small Interfering) RN - 0 (Receptors, IgG) RN - 0 (phosphatidylinositol 3-phosphate) RN - EC 3.1.3.48 (Mtmr4 protein, mouse) RN - EC 3.1.3.48 (Protein Tyrosine Phosphatases, Non-Receptor) SB - IM MH - Actins/metabolism MH - Animals MH - Endosomes/metabolism MH - Humans MH - Immunoglobulin G/immunology MH - Lysosomes/metabolism MH - Macrophages/cytology/metabolism MH - Mice MH - Mycobacterium marinum/pathogenicity MH - *Phagocytosis MH - Phagosomes/*metabolism MH - Phosphatidylinositol Phosphates/*metabolism MH - Protein Tyrosine Phosphatases, Non-Receptor/antagonists & inhibitors/genetics/*metabolism MH - RAW 264.7 Cells MH - RNA Interference MH - RNA, Small Interfering/metabolism MH - Receptors, IgG/metabolism MH - Signal Transduction PMC - PMC6851315 OTO - NOTNLM OT - Fc-gamma receptor OT - innate immunity OT - macrophage OT - mycobacteria OT - myotubularin-related protein-4 (MTMR4) OT - phagocytosis OT - phagosome OT - phosphatidylinositol 3-phosphate (PtdIns(3)P) OT - phosphatidylinositol phosphatase COIS- The authors declare that they have no conflicts of interest with the contents of this article EDAT- 2019/09/24 06:00 MHDA- 2020/06/09 06:00 PMCR- 2020/11/08 CRDT- 2019/09/24 06:00 PHST- 2019/04/30 00:00 [received] PHST- 2019/09/11 00:00 [revised] PHST- 2019/09/24 06:00 [pubmed] PHST- 2020/06/09 06:00 [medline] PHST- 2019/09/24 06:00 [entrez] PHST- 2020/11/08 00:00 [pmc-release] AID - S0021-9258(20)30515-9 [pii] AID - RA119.009133 [pii] AID - 10.1074/jbc.RA119.009133 [doi] PST - ppublish SO - J Biol Chem. 2019 Nov 8;294(45):16684-16697. doi: 10.1074/jbc.RA119.009133. Epub 2019 Sep 22.