title: Ribosome dimerization is essential for the efficient regrowth of Bacillus subtilis.
abstract: Ribosome dimers are a translationally inactive form of ribosomes found in Escherichia coli and many other bacterial cells. In this study, we found that the 70S ribosomes of Bacillus subtilis dimerized during the early stationary phase and these dimers remained in the cytoplasm until regrowth was initiated. Ribosome dimerization during the stationary phase required the hpf gene, which encodes a homologue of the E. coli hibernation-promoting factor (Hpf). The expression of hpf was induced at an early stationary phase and its expression was observed throughout the rest of the experimental period, including the entire 6 h of the stationary phase. Ribosome dimerization followed the induction of hpf in WT cells, but the dimerization was impaired in cells harbouring a deletion in the hpf gene. Although the absence of ribosome dimerization in these Hpf-deficient cells did not affect their viability in the stationary phase, their ability to regrow from the stationary phase decreased. Thus, following the transfer of stationary-phase cells to fresh LB medium, Δhpf mutant cells grew slower than WT cells. This observed lag in growth of Δhpf cells was probably due to a delay in restoring their translational activity. During regrowth, the abundance of ribosome dimers in WT cells decreased with a concomitant increase in the abundance of 70S ribosomes and growth rate. These results suggest that the ribosome dimers, by providing 70S ribosomes to the cells, play an important role in facilitating rapid and efficient regrowth of cells under nutrient-rich conditions.
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Genki
authors.initials: G
authors.lastname: Akanuma
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kazo
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Tagami
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Hirona
authors.initials: H
authors.lastname: Hiraoka
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.|Microbial Genetics Laboratory, Genetic Strains Research Center, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yano
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.|Department of Biotechnology, Graduate School of Agriculture and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Hanai
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.|Fukushima Medical University, Hiragaoka 1, Fukushima 960-1295, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nanamiya
authors.affiliation: Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kato-Yamada
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 155-8502, Japan.|Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Fujio
authors.initials: F
authors.lastname: Kawamura
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D019281:Dimerization; D017353:Gene Deletion; D020869:Gene Expression Profiling; D050296:Microbial Viability; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D012269:Ribosomal Proteins