Focal adhesion kinase is involved in type III group B streptococcal invasion of human brain microvascular endothelial cells.
Group B streptococcus (GBS), the leading cause of neonatal meningitis, has been shown to invade human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. GBS invasion of HBMEC has been shown to require the host cell actin cytoskeleton rearrangements. The present study examined the mechanisms underlying actin cytoskeleton rearrangements that are involved in type III GBS invasion of HBMEC. We showed that type III GBS invasion was inhibited by genistein, a general tyrosine kinase inhibitor (mean 54% invasion decrease at 100 microM), and LY294002, a phosphatidylinositol 3 (PI3) kinase inhibitor (mean 70% invasion decrease at 50 microM), but not by PP2, an inhibitor of the Src family tyrosine kinases. We subsequently showed that the focal adhesion kinase (FAK) was the one of the host proteins tyrosine phosphorylated by type III GBS. Over-expression of a dominant negative form of the FAK C-terminal domain significantly decreased type III GBS invasion of HBMEC (mean 51% invasion decrease). In addition, we showed that FAK phosphorylation correlated with its association of paxillin, an adapter protein of actin filament, and PI3-kinase subunit p85. This is the first demonstration that FAK phosphorylation and its association with paxillin and PI3 kinase play a key role in type III GBS invasion of HBMEC.
Shin
Sooan
S
Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Park 256, Baltimore, MD 21287, USA.
Paul-Satyaseela
Maneesh
M
Maneesh
Paul-Satyaseela
PS
Lee
Jong-Seok
JS
Romer
Lewis H
LH
Kim
Kwang Sik
KS
D000199:Actins / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000201:enzymology* / Q000382:microbiology*; D015153:Blotting, Western; D002867:Chromones / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism / Q000382:microbiology; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000382:microbiology; D004789:Enzyme Activation; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D051419:Paxillin / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D013290:Streptococcal Infections / Q000201:enzymology* / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000472:pathogenicity*
C412373:AG 1879; D000199:Actins; D002867:Chromones; D009025:Morpholines; D051419:Paxillin; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D019833:Genistein; D019869:Phosphatidylinositol 3-Kinases; D051416:Focal Adhesion Protein-Tyrosine Kinases