Regulation of polar flagellar number by the flhF and flhG genes in Vibrio alginolyticus.
The number and location of bacterial flagella vary with the species. The Vibrio alginolyticus cell has a single polar flagellum, which is driven by sodium ions. We selected mutants on the basis of reduced swarming ability on soft agar plates. Among them, we found two mutants with multiple polar flagella, and named them KK148 and NMB155. In Pseudomonas species, it is known that FlhF and FleN, which are FtsY and MinD homologs, respectively, are involved in regulation of flagellar placement and number, respectively. We cloned homologous genes of V. alginolyticus, flhF and flhG. KK148 cells had a nonsense mutation in flhG; cells expressing transgenic flhG recovered the swarming ability and had a reduced number of polar flagella. NMB155 cells did not have a mutation in either flhF or flhG. In wild-type cells, expression of flhF increased the number of polar flagella; in contrast, expression of flhG reduced both the number of polar flagella and the swarming ability. These results suggest that FlhG negatively regulates the number of polar flagella in V. alginolyticus. KK148 cells expressing both flhF and flhG exhibited fewer polar flagella and better swarming ability than KK148 cells expressing flhG alone, suggesting that FlhG acts with FlhF.
Kusumoto
Akiko
A
Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602.
Kamisaka
Kenji
K
Yakushi
Toshiharu
T
Terashima
Hiroyuki
H
Shinohara
Akari
A
Homma
Michio
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D005407:Flagella; D005408:Flagellin / Q000378:metabolism; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D016296:Mutagenesis; D017386:Sequence Homology, Amino Acid; D044149:Vibrio alginolyticus / Q000235:genetics* / Q000378:metabolism / Q000502:physiology
D001426:Bacterial Proteins; D005408:Flagellin; C078317:flhF protein, Bacteria; D020559:Monomeric GTP-Binding Proteins