TY - JOUR
T1 - Identification of genes controlled by the essential YycFG two-component system reveals a role for biofilm modulation in Staphylococcus epidermidis
AU - Xu, Tao
AU - Wu, Yang
AU - Lin, Zhiwei
AU - Bertram, Ralph
AU - Götz, Friedrich
AU - Zhang, Ying
AU - Qu, Di
N1 - Funding Information:
We thank Timothy J. Foster, Trinity College, Dublin, Ireland, for providing the strain E. coli DC10B, and A. L. Cheung, Dartmouth Medical School of Hanover, for providing the plasmid pALC2073. We appreciate the help from Liam Good, The Royal Veterinary College, United Kingdom, who provided the plasmid pHN678 and suggestions about asRNA. This study was supported by the National Natural Science Foundation of China (81671982, 81271791, and 81571955) and the National Science and the Technology Major Project of China (2012ZX09301002-005 and 2012ZX10003008-010).
Publisher Copyright:
© 2017 Xu, Wu, Lin, Bertram, Götz, Zhang and Qu.
PY - 2017/4/26
Y1 - 2017/4/26
N2 - Biofilms play a crucial role in the pathogenicity of Staphylococcus epidermidis, while little is known about whether the essential YycFG two-component signal transduction system (TCS) is involved in biofilm formation. We used antisense RNA (asRNA) to silence the yycFG TCS in order to study its regulatory functions in S. epidermidis. Strain 1457 expressing asRNAyycF exhibited a significant delay (~4-5 h) in entry to log phase, which was partially complemented by overexpressing ssaA. The expression of asRNAyycF and asRNAyycG resulted in a 68 and 50% decrease in biofilm formation at 6 h, respectively, while they had no significant inhibitory effect on 12 h biofilm formation. The expression of asRNAyycF led to a ~5-fold increase in polysaccharide intercellular adhesion (PIA) production, but it did not affect the expression of accumulation-associated protein (Aap) or the release of extracellular DNA. Consistently, quantitative real-time PCR showed that silencing yycF resulted in an increased transcription of biofilm-related genes, including icaA, arlR, sarA, sarX, and sbp. An in silico search of the YycF regulon for the conserved YycF recognition pattern and a modified motif in S. epidermidis, along with additional gel shift and DNase I footprinting assays, showed that arlR, sarA, sarX, and icaA are directly regulated by YycF. Our data suggests that YycFG modulates S. epidermidis biofilm formation in an ica-dependent manner.
AB - Biofilms play a crucial role in the pathogenicity of Staphylococcus epidermidis, while little is known about whether the essential YycFG two-component signal transduction system (TCS) is involved in biofilm formation. We used antisense RNA (asRNA) to silence the yycFG TCS in order to study its regulatory functions in S. epidermidis. Strain 1457 expressing asRNAyycF exhibited a significant delay (~4-5 h) in entry to log phase, which was partially complemented by overexpressing ssaA. The expression of asRNAyycF and asRNAyycG resulted in a 68 and 50% decrease in biofilm formation at 6 h, respectively, while they had no significant inhibitory effect on 12 h biofilm formation. The expression of asRNAyycF led to a ~5-fold increase in polysaccharide intercellular adhesion (PIA) production, but it did not affect the expression of accumulation-associated protein (Aap) or the release of extracellular DNA. Consistently, quantitative real-time PCR showed that silencing yycF resulted in an increased transcription of biofilm-related genes, including icaA, arlR, sarA, sarX, and sbp. An in silico search of the YycF regulon for the conserved YycF recognition pattern and a modified motif in S. epidermidis, along with additional gel shift and DNase I footprinting assays, showed that arlR, sarA, sarX, and icaA are directly regulated by YycF. Our data suggests that YycFG modulates S. epidermidis biofilm formation in an ica-dependent manner.
KW - Antisense RNA
KW - Biofilm
KW - Staphylococcus epidermidis
KW - Two-component signal transduction system
KW - YycFG
UR - http://www.scopus.com/inward/record.url?scp=85018319171&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85018319171&partnerID=8YFLogxK
U2 - 10.3389/fmicb.2017.00724
DO - 10.3389/fmicb.2017.00724
M3 - Article
C2 - 28491057
AN - SCOPUS:85018319171
SN - 1664-302X
VL - 8
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
IS - APR
M1 - 724
ER -