The enigmatic methyltransferase, DNMT2 (DNA methyltransferase 2), structurally resembles a DNA methyltransferase, but has been shown to be a tRNA methyltransferase targeting cytosine within a specific CpG in different tRNA molecules. We had previously shown that, during environmental stress conditions, DNMT2 is re-localized from the nucleus to the cytoplasmic stress granules (SGs) and is associated with RNA-processing proteins. In the present study, we show that DNMT2 binds and methylates various mRNA species in a sequence-independent manner and gets re-localized to SGs in a phosphorylation-dependent manner. Importantly, our results indicate that HIV-1 enhances its survivability in the host cell by utilizing this RNA methylation capability of DNMT2 to increase the stability of its own genome. Upon infection, DNMT2 re-localizes from the nucleus to the SGs and methylates HIV-1 RNA. This DNMT2-dependent methylation provided post-transcriptional stability to the HIV-1 RNA. Furthermore, DNMT2 overexpression increased the HIV-1 viral titre. This would suggest that HIV hijacks the RNA-processing machinery within the SGs to ensure its own survival in the host cell. Thus, our findings provide for a novel mechanism by which virus tries to modulate the host cell machinery to its own advantage.

Microtitre plate method was found to be a more sensitive method for biofilm detection. This study demonstrates a high propensity among the clinical isolates of A. baumannii to form biofilm and a significant association of biofilms with multiple drug resistance. Presence of bla PER-1 appears to be more critical for cell adherence than for biofilm formation.

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Secretory N-acyl homoserine lactones (AHLs) mediate quorum sensing (QS) in bacteria. AHLs are shown to be inhibitory for an unrelated group of bacteria and might mimic host signalling elements, thereby subverting the regulatory events in host cells. This study investigated the AHL produced by Acinetobacter baumannii and analysed its effect on other bacterial species and mammalian cells. Chemically characterized AHL had an m/z value of 325 with a molecular formula C18H31NO4 and showed its inhibitory potential against Staphylococcus aureus. Molecular docking studies identified D-alanine-D-alanine synthetase A, a cell wall synthesizing enzyme of S. aureus having a strong binding affinity towards AHL. Electron microscopy showed the disruption and sloughing off of the S. aureus cell wall when treated with AHL. In vitro experiments revealed that this bacteriostatic AHL showed time-dependent activity and induced apoptosis in cancer cell lines. This compound could be a potential structural backbone for constructing new AHL analogues against S. aureus. The findings emphasize the need to re-evaluate all previously characterized AHLs for any additional new biological functions other than QS.