Send to:

Choose Destination
See comment in PubMed Commons below
J Basic Microbiol. 2014 Sep;54(9):1017-21. doi: 10.1002/jobm.201300007. Epub 2013 May 26.

SecA2 is not required for secretion of the surface autolysin IspC in Listeria monocytogenes serotype 4b.

Author information

  • 1Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Ottawa, Ontario, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada.


Listeria monocytogenes is one of several Gram-positive bacteria known to contain an auxiliary ATPase (SecA2) involved in the Sec secretion of a subset of proteins important to bacterial pathogenesis, including autolysins. It is not known if IspC, a novel surface-associated autolysin essential for full virulence of L. monocytogenes serotype 4b, is SecA2-dependent for secretion. By creating a secA2 gene deletion (ΔsecA2) mutant from the wild type (WT) L. monocytogenes serotype 4b strain, in combination with the proteomic analysis of surface proteins and those secreted into the medium from both the mutant and the WT, we confirmed previous findings that two autolysins (p60 and NamA) are SecA2-dependent for secretion. However, this approach did not identify IspC as one of the surface proteins affected by the SecA2 deletion. Further experiments with immunofluorescence microscopy and Western blotting indicated that IspC was well displayed on the surface of both the ΔsecA2 mutant and WT cells, while p60 was not, clearly indicating that the secretion of IspC is not attributed to the SecA2 pathway. This finding sets IspC apart from other autolysins involved in virulence, such as p60 and NamA, in that SecA2 is not required for IspC secretion.

© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


IspC; Listeria monocytogenes; SecA2; Secretion

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Write to the Help Desk