| Title: | ABC transporter content diversity in Streptococcus pneumoniae impacts competence regulation and bacteriocin production |
| Author(s): | Wang CY; Patel N; Wholey WY; Dawid S; |
| Address: | "Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109. Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109. Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109; sdawid@med.umich.edu" |
| ISSN/ISBN: | 1091-6490 (Electronic) 0027-8424 (Print) 0027-8424 (Linking) |
| Abstract: | "The opportunistic pathogen Streptococcus pneumoniae (pneumococcus) uses natural genetic competence to increase its adaptability through horizontal gene transfer. One method of acquiring DNA is through predation of neighboring strains with antimicrobial peptides called 'bacteriocins.' Competence and production of the major family of pneumococcal bacteriocins, pneumocins, are regulated by the quorum-sensing systems com and blp, respectively. In the classical paradigm, the ABC transporters ComAB and BlpAB each secretes its own system's signaling pheromone and in the case of BlpAB also secretes the pneumocins. While ComAB is found in all pneumococci, only 25% of strains encode an intact version of BlpAB [BlpAB(+)] while the rest do not [BlpAB(-)]. Contrary to the classical paradigm, it was previously shown that BlpAB(-) strains can activate blp through ComAB-mediated secretion of the blp pheromone during brief periods of competence. To better understand the full extent of com-blp crosstalk, we examined the contribution of each transporter to competence development and pneumocin secretion. We found that BlpAB(+) strains have a greater capacity for competence activation through BlpAB-mediated secretion of the com pheromone. Similarly, we show that ComAB and BlpAB are promiscuous and both can secrete pneumocins. Consequently, differences in pneumocin secretion between BlpAB(+) and BlpAB(-) strains derive from the regulation and kinetics of transporter expression rather than substrate specificity. We speculate that BlpAB(-) strains (opportunists) use pneumocins mainly in a narrowly tailored role for DNA acquisition and defense during competence while BlpAB(+) strains (aggressors) expand their use for the general inhibition of rival strains" |
| Keywords: | "ATP-Binding Cassette Transporters/*metabolism Animals Bacterial Proteins/*metabolism Bacteriocins/*metabolism Female Gene Expression Regulation, Bacterial/physiology Membrane Transport Proteins/metabolism Mice Mice, Inbred BALB C Nasopharynx/metabolism/mi;" |
| Notes: | "MedlineWang, Charles Y Patel, Nisha Wholey, Wei-Yun Dawid, Suzanne eng R01 AI101285/AI/NIAID NIH HHS/ R56 AI101285/AI/NIAID NIH HHS/ T32 AI007528/AI/NIAID NIH HHS/ T32 GM007863/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural 2018/06/06 Proc Natl Acad Sci U S A. 2018 Jun 19; 115(25):E5776-E5785. doi: 10.1073/pnas.1804668115. Epub 2018 Jun 4" |
