title: Group B Streptococcus induces tyrosine phosphorylation of annexin V and glutathione S-transferase in human umbilical vein endothelial cells.
abstract: Group B Streptococcus (GBS), a human pathogen that causes infection and invasive diseases in newborns, pregnant women and immunocompromised adults, has been shown to invade human umbilical vein endothelial cells (HUVECs). The objective of this study was to investigate the molecular mechanisms underlying GBS-HUVEC interaction, focusing specifically on the responsiveness of host protein tyrosine kinase (PTK). We found that GBS serotypes III and V induced actin reorganization and formation of stress fibers into HUVECs. Since rearrangements of the actin cytoskeleton into eukaryotic cells are usually associated with the activation of PTK, we decided to follow the expression of this class of kinases in the course of the interaction. Unexpectedly, treatment of HUVECs with genistein greatly increased both cytoadherence and intracellular viability, for all GBS strains studied. GBS increased tyrosine phosphorylation of two proteins with an apparent molecular mass of 35 and 23 kDa in HUVECs as demonstrated by Western blot analysis with anti-phosphotyrosine antibodies. Mass spectra analysis identified these proteins as annexin V and glutathione S-transferase. Studies are in progress to identify the role of these two proteins on GBS-HUVEC interaction.
authors.affiliation: UERJ-Instituto Biologia Roberto Alcântara Gomes, Depto Biologia Celular e Genética, R. São Francisco Xavier, RJ 20.550-013, Rio de Janeiro, Brazil.
authors.forename: Gabriela S
authors.initials: GS
authors.lastname: Santos
authors.forename: Carla-Veronica
authors.initials: CV
authors.lastname: Loureiro y Penha
authors.forename: Ana Luiza
authors.initials: AL
authors.lastname: Mattos-Guaraldi
authors.forename: Márcia
authors.initials: M
authors.lastname: Attias
authors.forename: Leila M
authors.initials: LM
authors.lastname: Lopes-Bezerra
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Silva-Filho
authors.forename: Prescilla E
authors.initials: PE
authors.lastname: Nagao
mesh_terms: D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D017304:Annexin A5 / Q000737:chemistry / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D015638:Cytochalasin D / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D019833:Genistein / Q000494:pharmacology; D005982:Glutathione Transferase / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry; D019000:Phosphotyrosine / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D013292:Streptococcus agalactiae / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology*
chemical_list: D000199:Actins; D017304:Annexin A5; D010455:Peptides; D019000:Phosphotyrosine; D015638:Cytochalasin D; D019833:Genistein; D005982:Glutathione Transferase