title: Single transmembrane peptide DinQ modulates membrane-dependent activities.
abstract: The functions of several SOS regulated genes in Escherichia coli are still unknown, including dinQ. In this work we characterize dinQ and two small RNAs, agrA and agrB, with antisense complementarity to dinQ. Northern analysis revealed five dinQ transcripts, but only one transcript (+44) is actively translated. The +44 dinQ transcript translates into a toxic single transmembrane peptide localized in the inner membrane. AgrB regulates dinQ RNA by RNA interference to counteract DinQ toxicity. Thus the dinQ-agr locus shows the classical features of a type I TA system and has many similarities to the tisB-istR locus. DinQ overexpression depolarizes the cell membrane and decreases the intracellular ATP concentration, demonstrating that DinQ can modulate membrane-dependent processes. Augmented DinQ strongly inhibits marker transfer by Hfr conjugation, indicating a role in recombination. Furthermore, DinQ affects transformation of nucleoid morphology in response to UV damage. We hypothesize that DinQ is a transmembrane peptide that modulates membrane-dependent activities such as nucleoid compaction and recombination.
authors: Centre for Molecular Biology and Neuroscience (CMBN), University of Oslo and Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors: Ragnhild
authors: R
authors: Weel-Sneve
authors: Knut Ivan
authors: KI
authors: Kristiansen
authors: Ingvild
authors: I
authors: Odsbu
authors: Bjørn
authors: B
authors: Dalhus
authors: James
authors: J
authors: Booth
authors: Torbjørn
authors: T
authors: Rognes
authors: Kirsten
authors: K
authors: Skarstad
authors: Magnar
authors: M
authors: Bjørås
mesh_terms: D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D003593:Cytoplasm; D004249:DNA Damage / Q000528:radiation effects; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000528:radiation effects; D008565:Membrane Proteins / Q000235:genetics*; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D016372:RNA, Antisense / Q000235:genetics / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic / Q000235:genetics; D013014:SOS Response, Genetics / Q000528:radiation effects; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: C489527:ArsR protein, E coli; C581618:DinQ protein, E coli; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D010455:Peptides; D016372:RNA, Antisense; D012329:RNA, Bacterial; D015534:Trans-Activators