Mycobacterium tuberculosis infection remains a major threat to human health worldwide. Drug treatments against tuberculosis (TB) induce expression of several mycobacterial proteins, including IniA, but its structure and function remain poorly understood. Here, we report the structures of Mycobacterium smegmatis IniA in both the nucleotide-free and GTP-bound states. The structures reveal that IniA folds as a bacterial dynamin-like protein (BDLP) with a canonical GTPase domain followed by two helix-bundles (HBs), named Neck and Trunk. The distal end of its Trunk domain exists as a lipid-interacting (LI) loop, which binds to negatively charged lipids for membrane attachment. IniA does not form detectable nucleotide-dependent dimers in solution. However, lipid tethering indicates nucleotide-independent association of IniA on the membrane. IniA also deforms membranes and exhibits GTP-hydrolyzing dependent membrane fission. These results confirm the membrane remodeling activity of BDLP and suggest that IniA mediates TB drug-resistance through fission activity to maintain plasma membrane integrity.
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http://dx.doi.org/10.1038/s41467-019-11860-z | DOI Listing |
Int J Mol Sci
January 2025
Institute for Maternal and Child Health IRCCS Burlo Garofolo, Via dell'Istria, 65, 34137 Trieste, Italy.
Pathogenic variants in , encoding dynamin-like protein-1 (DRP1), cause a lethal encephalopathy. DRP1 defective function results in altered mitochondrial networks, characterized by elongated/spaghetti-like, highly interconnected mitochondria. We validated in yeast the pathogenicity of a de novo variant identified by whole exome sequencing performed more than 10 years after the patient's death.
View Article and Find Full Text PDFAutophagy
December 2024
Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, Barcelona, Spain.
MFN1 (mitofusin 1) and MFN2 are key players in mitochondrial fusion, endoplasmic reticulum (ER)-mitochondria juxtaposition, and macroautophagy/autophagy. However, the mechanisms by which these proteins participate in these processes are poorly understood. Here, we studied the interactomes of these two proteins by using CRISPR-Cas9 technology to insert an HA-tag at the C terminus of MFN1 and MFN2, and thus generating HeLa cell lines that endogenously expressed MFN1-HA or MFN2-HA.
View Article and Find Full Text PDFmBio
January 2025
Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
Dynamins, or dynamin-related proteins (DRPs), are large mechano-sensitive GTPases that mediate membrane dynamics or organellar fission/fusion events. encodes three dynamin-like proteins whose functions are poorly understood. Here, we demonstrate that one of these dynamin-related proteins, PfDyn2, is required to divide both the apicoplast and the mitochondrion, a striking divergence from the biology of related parasites.
View Article and Find Full Text PDFCell Commun Signal
November 2024
Institute for Molecular Medicine I, Medical Faculty, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
Targeting mitochondrial metabolism represents a promising approach for cancer treatment. Here, we investigated the mitotoxic potential of the polybrominated diphenyl ether bromoxib, a natural compound isolated from the marine sponge Dysidea family. We could show that bromoxib comprised strong cytotoxicity in different leukemia and lymphoma cell lines (such as HL60, HPBALL, Jurkat, K562, KOPTK1, MOLT4, SUPB15 and Ramos), but also in solid tumor cell lines (such as glioblastoma cell lines SJ-GBM2 and TP365MG).
View Article and Find Full Text PDFJ Gen Physiol
December 2024
LAPEC UPR-4278, Avignon Université, Avignon, France.
Mitochondrial fission is a key trigger of cardiac ischemia-reperfusion injuries (IR). Exercise training is an efficient cardioprotective strategy, but its impact on mitochondrial fragmentation during IR remains unknown. Using isolated rat hearts, we found that exercise training limited the activation of dynamin-like protein 1 and limited mitochondrial fragmentation during IR.
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