+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

The surface protein Srr-1 of Streptococcus agalactiae binds human keratin 4 and promotes adherence to epithelial HEp-2 cells



The surface protein Srr-1 of Streptococcus agalactiae binds human keratin 4 and promotes adherence to epithelial HEp-2 cells



Infection and Immunity 75(11): 5405-5414



Streptococcus agalactiae is frequently the cause of bacterial sepsis and meningitis in neonates. In addition, it is a commensal bacterium that colonizes the mammalian gastrointestinal tract. During its commensal and pathogenic lifestyles, S. agalactiae colonizes and invades a number of host compartments, thereby interacting with different host proteins. In the present study, the serine-rich repeat protein Srr-1 from S. agalactiae was functionally investigated. Immunofluorescence microscopy showed that Srr-1 was localized on the surface of streptococcal cells. The Srr-1 protein was shown to interact with a 62-kDa protein in human saliva, which was identified by matrix-assisted laser desorption ionization-time-of-flight analysis as human keratin 4 (K4). Immunoblot and enzyme-linked immunosorbent assay experiments allowed us to narrow down the K4 binding domain in Srr-1 to a region of 157 amino acids (aa). Furthermore, the Srr-1 binding domain of K4 was identified in the C-terminal 255 aa of human K4. Deletion of the srr-1 gene in the genome of S. agalactiae revealed that this gene plays a role in bacterial binding to human K4 and that it is involved in adherence to epithelial HEp-2 cells. Binding to immobilized K4 and adherence to HEp-2 cells were restored by introducing the srr-1 gene on a shuttle plasmid into the srr-1 mutant. Furthermore, incubation of HEp-2 cells with the K4 binding domain of Srr-1 blocked S. agalactiae adherence to epithelial cells in a dose-dependent fashion. This is the first report describing the interaction of a bacterial protein with human K4.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 017299825

Download citation: RISBibTeXText

PMID: 17709412

DOI: 10.1128/iai.00717-07


Related references

The fibrinogen receptor FbsA promotes adherence of Streptococcus agalactiae to human epithelial cells. Infection and Immunity 72(11): 6197-6205, 2004

The novel fibrinogen-binding protein FbsB promotes Streptococcus agalactiae invasion into epithelial cells. Infection and Immunity 72(6): 3495-3504, 2004

Effect of chelating agents on the growth, surface polypeptide synthesis and interaction of Streptococcus agalactiae with human epithelial cells. Molecular Medicine Reports 2(1): 81-84, 2009

The R28 protein of Streptococcus pyogenes is related to several group B streptococcal surface proteins, confers protective immunity and promotes binding to human epithelial cells. Molecular Microbiology 33(1): 208-219, 1999

Adherence to and invasion of human brain microvascular endothelial cells are promoted by fibrinogen-binding protein FbsA of Streptococcus agalactiae. Infection and Immunity 73(7): 4404-4409, 2005

Expression of protein F, the fibronectin-binding protein of Streptococcus pyogenes JRS4, in heterologous streptococcal and enterococcal strains promotes their adherence to respiratory epithelial cells. Infection and Immunity 60(12): 5119-5125, 1992

Dual role for pilus in adherence to epithelial cells and biofilm formation in Streptococcus agalactiae. Plos Pathogens 5(5): E1000422, 2009

Role of pilus proteins in adherence and invasion of Streptococcus agalactiae to the lung and cervical epithelial cells. Journal of Biological Chemistry 288(6): 4023-4034, 2013

The role of streptococcus agalactiae selective adherence to epithelial cells of the cow mammary gland in the onset of mastitis. Veterinarski Glasnik 41(11-12): 1034-1037, 1987

The group B Streptococcus alpha C protein binds to integrin on human epithelial cells. 2006

The role of surface structures of Streptococcus agalactiae in adhesion to epithelial cells. Medycyna Doswiadczalna i Mikrobiologia 42(3-4): 101-107, 1990

Effect of two probiotic strains of Lactobacillus on in vitro adherence of Listeria monocytogenes, Streptococcus agalactiae, and Staphylococcus aureus to vaginal epithelial cells. Current Microbiology 68(6): 679-684, 2014

Streptococcus pneumoniae and Staphylococcus aureus surface properties in relation to their adherence to human buccal epithelial cells. Research in Microbiology 140(8): 563-567, 1989

Expression, purification, crystallization and preliminary X-ray diffraction studies of the human keratin 4-binding domain of serine-rich repeat protein 1 from Streptococcus agalactiae. Acta Crystallographica. Section F Structural Biology and Crystallization Communications 67(Pt 12): 1582-1585, 2011

The group B streptococcal alpha C protein binds a1b1-integrin through a novel KTD motif that promotes internalization of GBS within human epithelial cells. 2007