TY - JOUR
T1 - Untangling Flavobacterium johnsoniae gliding motility and protein secretion
AU - Johnston, Joseph J.
AU - Shrivastava, Abhishek
AU - McBride, Mark J.
N1 - Funding Information:
We thank Doug Steeber and Heather Owen for assistance with the flow cytometry and immunofluorescence microscopy experiments, respectively. This research was supported by grants MCB-1021721 and MCB-1516990 from the National Science Foundation. The funder had no role in the study design, data collection and interpretation, or the decision to submit the work for publication
Funding Information:
We thank Doug Steeber and Heather Owen for assistance with the flow cytometry and immunofluorescence microscopy experiments, respectively. This research was supported by grants MCB-1021721 and MCB-1516990 from the National Science Foundation. The funder had no role in the study design, data collection and interpretation, or the decision to submit the work for publication.
Publisher Copyright:
© 2017 American Society for Microbiology.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Flavobacterium johnsoniae exhibits rapid gliding motility over surfaces. At least 20 genes are involved in this process. Seven of these, gldK, gldL, gldM, gldN, sprA, sprE, and sprT, encode proteins of the type IX protein secretion system (T9SS). The T9SS is required for surface localization of the motility adhesins SprB and RemA, and for secretion of the soluble chitinase ChiA. Here, we demonstrate that the gliding motility proteins GldA, GldB, GldD, GldF, GldH, GldI, and GldJ are also essential for secretion. Cells with mutations in the genes encoding any of these seven proteins had normal levels of gldK mRNA but dramatically reduced levels of the GldK protein, which may explain the secretion defects of the motility mutants. GldJ is necessary for stable accumulation of GldK, and each mutant lacked the GldJ protein. F. johnsoniae cells that produced truncated GldJ, lacking eight to 13 amino acids from the C terminus, accumulated GldK but were deficient in gliding motility. SprB was secreted by these cells but was not propelled along their surfaces. This C-terminal region of GldJ is thus required for gliding motility but not for secretion. The identification of mutants that are defective for motility but competent for secretion begins to untangle the F. johnsoniae gliding motility machinery from the T9SS.
AB - Flavobacterium johnsoniae exhibits rapid gliding motility over surfaces. At least 20 genes are involved in this process. Seven of these, gldK, gldL, gldM, gldN, sprA, sprE, and sprT, encode proteins of the type IX protein secretion system (T9SS). The T9SS is required for surface localization of the motility adhesins SprB and RemA, and for secretion of the soluble chitinase ChiA. Here, we demonstrate that the gliding motility proteins GldA, GldB, GldD, GldF, GldH, GldI, and GldJ are also essential for secretion. Cells with mutations in the genes encoding any of these seven proteins had normal levels of gldK mRNA but dramatically reduced levels of the GldK protein, which may explain the secretion defects of the motility mutants. GldJ is necessary for stable accumulation of GldK, and each mutant lacked the GldJ protein. F. johnsoniae cells that produced truncated GldJ, lacking eight to 13 amino acids from the C terminus, accumulated GldK but were deficient in gliding motility. SprB was secreted by these cells but was not propelled along their surfaces. This C-terminal region of GldJ is thus required for gliding motility but not for secretion. The identification of mutants that are defective for motility but competent for secretion begins to untangle the F. johnsoniae gliding motility machinery from the T9SS.
KW - Flavobacterium
KW - Gliding motility
KW - Protein secretion
KW - Type IX secretion system
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U2 - 10.1128/JB.00362-17
DO - 10.1128/JB.00362-17
M3 - Article
C2 - 29109184
AN - SCOPUS:85039048599
SN - 0021-9193
VL - 200
JO - Journal of bacteriology
JF - Journal of bacteriology
IS - 2
M1 - e00362-17
ER -