TY - JOUR
T1 - A Global Transcriptional Switch between the Attack and Growth Forms of Bdellovibrio bacteriovorus
AU - Karunker, Iris
AU - Rotem, Or
AU - Dori-Bachash, Mally
AU - Jurkevitch, Edouard
AU - Sorek, Rotem
N1 - We thank Omri Wurtzel, Shany Doron, Daniel Dar and Ofir Avidan for comments and useful discussion. Funding: RS was supported, in part, by the ERC-StG program (grant 260432), the Minerva Foundation, and by a DIP grant from the Deutsche Forschungsgemeinschaft. EJ was supported by the Israel Science Foundation (grant 1290/08). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Author Contributions- Conceived and designed the experiments: EJ RS. Performed the experiments: IK OR MDB. Analyzed the data: IK OR EJ RS. Contributed reagents/materials/analysis tools: EJ RS. Wrote the paper: IK OR EJ RS.
PY - 2013/4/16
Y1 - 2013/4/16
N2 - Bdellovibrio bacteriovorus is an obligate predator of bacteria ubiquitously found in the environment. Its life cycle is composed of two essential phases: a free-living, non-replicative, fast swimming attack phase (AP) wherein the predator searches for prey; and a non-motile, actively dividing growth phase (GP) in which it consumes the prey. The molecular regulatory mechanisms governing the switch between AP and GP are largely unknown. We used RNA-seq to generate a single-base-resolution map of the Bdellovibrio transcriptome in AP and GP, revealing a specific "AP" transcriptional program, which is largely mutually exclusive of the GP program. Based on the expression map, most genes in the Bdellovibrio genome are classified as "AP only" or "GP only". We experimentally generated a genome-wide map of 140 AP promoters, controlling the majority of AP-specific genes. This revealed a common sigma-like DNA binding site highly similar to the E. coli flagellar genes regulator sigma28 (FliA). Further analyses suggest that FliA has evolved to become a global AP regulator in Bdellovibrio. Our results also reveal a non-coding RNA that is massively expressed in AP. This ncRNA contains a c-di-GMP riboswitch. We suggest it functions as an intracellular reservoir for c-di-GMP, playing a role in the rapid switch from AP to GP.
AB - Bdellovibrio bacteriovorus is an obligate predator of bacteria ubiquitously found in the environment. Its life cycle is composed of two essential phases: a free-living, non-replicative, fast swimming attack phase (AP) wherein the predator searches for prey; and a non-motile, actively dividing growth phase (GP) in which it consumes the prey. The molecular regulatory mechanisms governing the switch between AP and GP are largely unknown. We used RNA-seq to generate a single-base-resolution map of the Bdellovibrio transcriptome in AP and GP, revealing a specific "AP" transcriptional program, which is largely mutually exclusive of the GP program. Based on the expression map, most genes in the Bdellovibrio genome are classified as "AP only" or "GP only". We experimentally generated a genome-wide map of 140 AP promoters, controlling the majority of AP-specific genes. This revealed a common sigma-like DNA binding site highly similar to the E. coli flagellar genes regulator sigma28 (FliA). Further analyses suggest that FliA has evolved to become a global AP regulator in Bdellovibrio. Our results also reveal a non-coding RNA that is massively expressed in AP. This ncRNA contains a c-di-GMP riboswitch. We suggest it functions as an intracellular reservoir for c-di-GMP, playing a role in the rapid switch from AP to GP.
UR - http://www.scopus.com/inward/record.url?scp=84876166445&partnerID=8YFLogxK
U2 - https://doi.org/10.1371/journal.pone.0061850
DO - https://doi.org/10.1371/journal.pone.0061850
M3 - Article
C2 - 23613952
SN - 1932-6203
VL - 8
JO - PLoS ONE
JF - PLoS ONE
IS - 4
M1 - e61850
ER -