title: The asymmetric distribution of the essential histidine kinase PdhS indicates a differentiation event in Brucella abortus.
abstract: Many organisms use polar localization of signalling proteins to control developmental events in response to completion of asymmetric cell division. Asymmetric division was recently reported for Brucella abortus, a class III facultative intracellular pathogen generating two sibling cells of slightly different size. Here we characterize PdhS, a cytoplasmic histidine kinase essential for B. abortus viability and homologous to the asymmetrically distributed PleC and DivJ histidine kinases from Caulobacter crescentus. PdhS is localized at the old pole of the large cell, and after division and growth, the small cell acquires PdhS at its old pole. PdhS may therefore be considered as a differentiation marker as it labels the old pole of the large cell. Moreover, PdhS colocalizes with its paired response regulator DivK. Finally, PdhS is able to localize at one pole in other alpha-proteobacteria, suggesting that a polar structure associating PdhS with one pole is conserved in these bacteria. We propose that a differentiation event takes place after the completion of cytokinesis in asymmetrically dividing alpha-proteobacteria. Altogether, these data suggest that prokaryotic differentiation may be much more widespread than expected.
authors.affiliation: Unité de Recherche en Biologie Moléculaire, University of Namur FUNDP, Namur, Belgium.
authors.forename: Régis
authors.initials: R
authors.lastname: Hallez
authors.forename: Johann
authors.initials: J
authors.lastname: Mignolet
authors.forename: Vincent
authors.initials: V
authors.lastname: Van Mullem
authors.forename: Maxime
authors.initials: M
authors.lastname: Wery
authors.forename: Jean
authors.initials: J
authors.lastname: Vandenhaute
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Letesson
authors.forename: Christine
authors.initials: C
authors.lastname: Jacobs-Wagner
authors.forename: Xavier
authors.initials: X
authors.lastname: De Bolle
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002003:Brucella abortus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D002417:Cattle; D002455:Cell Division / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D008264:Macrophages / Q000382:microbiology; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase