The pilus and porin of Neisseria gonorrhoeae cooperatively induce Ca2+ transients in infected epithelial cells

Ayala, Patricia; Wilbur, J. Scott; Wetzler, Lee M.; Tainer, John A.; Snyder, Aurelie; So, Magdalene

doi:10.1111/j.1462-5822.2005.00586.x

Cited by 23 publications

(25 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, the precursor to PIP3, phosphatidylinositol (4,5)-bisphosphate (PIP2), plays a key role in cytoskeletal-membrane adhesion (Raucher et al, 2000). Tfp retraction also induces calcium fluxes in the infected cell (Ayala et al, 2005) and tyrosine phosphorylation of numerous proteins, including PI-3K/Akt (Lee et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

Influence of type IV pilus retraction on the architecture of the Neisseria gonorrhoeae-infected cell cortex

et al. 2009

Self Cite

View full text Add to dashboard Cite

Early in infection, Neisseria gonorrhoeae can be observed to attach to the epithelial cell surface as microcolonies and induce dramatic changes to the host cell cortex. We tested the hypothesis that type IV pili (Tfp) retraction plays a role in the ultrastructure of both the host cell cortex and the bacterial microcolony. Using serial ultrathin sectioning, transmission electron microscopy and 3D reconstruction of serial 2D images, we have obtained what we believe to be the first 3D reconstructions of the N. gonorrhoeae-host cell interface, and determined the architecture of infected cell microvilli as well as the attached microcolony. Tfp connect both wild-type (wt) and Tfp retraction-deficient bacteria with each other, and with the host cell membrane. Tfp fibres and microvilli form a lattice in the wt microcolony and at its periphery. Wt microcolonies induce microvilli formation and increases of surface area, leading to an approximately ninefold increase in the surface area of the host cell membrane at the site of attachment. In contrast, Tfp retractiondeficient microcolonies do not affect these parameters. Wt microcolonies had a symmetrical, dome-shaped structure with a circular 'footprint', while Tfp retraction-deficient microcolonies were notably less symmetrical. These findings support a major role for Tfp retraction in microvilli and microcolony architecture. They are consistent with the biophysical attributes of Tfp and the effects of Tfp retraction on epithelial cell signalling. INTRODUCTIONNeisseria gonorrhoeae (the gonococcus, or GC) remains a significant public health concern. The Gram-negative diplococcus causes a million cases of gonorrhoea annually in Western Europe and North America, and over 62 million cases worldwide (World Health Organization). Humans are the only known reservoir for GC. The exquisite tropism of GC for man and the ability of GC to establish a carrier state (Turner et al., 2002) reflect a highly evolved relationship between pathogen and host.Gonococcal attachment is promoted by type IV pili (Tfp), peritrichous fibres that are 6 nm in width and up to several micrometres in length. The Tfp filament is composed of helical polymers of pilin subunits (Craig et al., 2006;Parge et al., 1995) and minor proteins (Carbonnelle et al., 2005;Winther-Larsen et al., 2005). Tfp participate in important biological processes such as DNA uptake/genetic exchange, twitching motility, attachment, and host cell signalling (Mattick, 2002;. These activities require, or are enhanced by, the retraction of Tfp fibres (Wolfgang et al., 2000).Gonococcal Tfp retraction is an activity that requires PilT, the Tfp retraction motor subunit (Wolfgang et al., 1998). Retracting Tfp generate strong 'pull' forces, ranging from 50 picoNewtons (pN) to 1 nanoNewton (nN) (Biais et al., 2008;Opitz et al., 2009). Repeated cycles of Tfp extension, substrate attachment and Tfp retraction allow GC to crawl over surfaces and aggregate into microcolonies. Tfp retraction from bacteria in a microcolony allows the community to craw...

show abstract

Section: Discussionmentioning

confidence: 99%

Influence of type IV pilus retraction on the architecture of the Neisseria gonorrhoeae-infected cell cortex

et al. 2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…Tfp retraction induces a number of responses in the infected epithelial cell. It triggers Ca 2ϩ and stress kinase signaling, cytoskeletal rearrangements, and cortical plaque formation and regulates epithelial gene expression (3,17,23,33). In turn, these host responses enhance N. gonorrhoeae aggregative behavior, promote bacterial invasion, and dampen apoptosis signaling (17, 23).…”

mentioning

confidence: 99%

Dynamics of Neisseria gonorrhoeae Attachment: Microcolony Development, Cortical Plaque Formation, and Cytoprotection

Higashi¹,

Lee²,

et al. 2007

Self Cite

View full text Add to dashboard Cite

Neisseria gonorrhoeae is the bacterium that causes gonorrhea, a major sexually transmitted disease and a significant cofactor for human immunodeficiency virus transmission. The retactile N. gonorrhoeae type IV pilus (Tfp) mediates twitching motility and attachment. Using live-cell microscopy, we reveal for the first time the dynamics of twitching motility by N. gonorrhoeae in its natural environment, human epithelial cells. Bacteria aggregate into microcolonies on the cell surface and induce a massive remodeling of the microvillus architecture. Surprisingly, the microcolonies are motile, and they fuse to form progressively larger structures that undergo rapid reorganization, suggesting that bacteria communicate with each other during infection. As reported, actin plaques form beneath microcolonies. Here, we show that cortical plaques comigrate with motile microcolonies. These activities are dependent on pilT, the Tfp retraction locus. Cultures infected with a pilT mutant have significantly higher numbers of apoptotic cells than cultures infected with the wild-type strain. Inducing pilT expression with isopropyl-␤-D-thiogalactopyranoside partially rescues cells from infection-induced apoptosis, demonstrating that Tfp retraction is intrinsically cytoprotective for the host. Tfp-mediated attachment is therefore a continuum of microcolony motility and force stimulation of host cell signaling, leading to a cytoprotective effect.Type IV pili (Tfp) are filamentous appendages expressed by a wide range of bacteria, including Synechocystis spp., Pseudomonas aeruginosa, Myxococcus xanthus, Xylella fastidiosa, Clostridium perfringens, enterohaemorrhagic and enteropathogenic Escherichia coli, Neisseria meningitidis, and Neisseria gonorrhoeae (29,32,37,50,54,56,61). The Tfp of several of these bacteria are known to retract, and retraction underlies twitching motility, DNA uptake, phage sensitivity, and social behavior, such as fruiting-body and biofilm formation.N. gonorrhoeae, the bacterium that causes gonorrhea, expresses multiple nonpolar retractile Tfp that promote attachment to epithelial cells (38). Retraction requires the ATPase PilT, which is proposed to disassemble the Tfp fiber (2,13,15). N. gonorrhoeae pilT null mutants express nonretractile Tfp (38,60). Cycles of Tfp extension, substrate tethering, and retraction enable N. gonorrhoeae to crawl on a glass coverslip or agar surface (twitching motility) (34). Twitching motility on epithelial cells has not been studied. Understanding N. gonorrhoeae motility behavior in this environment is important, as the bacterium infects only humans and cannot survive outside the human body.Mechanical forces of 50 to 100 pN are generated by the retraction of a Tfp fiber (24, 38). Thus, Tfp retraction allows N. gonorrhoeae to pull and exert physical stress on its substrate. Tfp retraction induces a number of responses in the infected epithelial cell. It triggers Ca 2ϩ and stress kinase signaling, cytoskeletal rearrangements, and cortical plaque formation and regulates epithelial gen...

show abstract

“…This interaction, as part of the invasion process, is able to increase intracellular calcium bursts (Ayala et al, 2005b). Moreover, the pilus of Neisseria gonorrhoeae, which shares substantial sequence conservation with N. meningitides, acts cooperatively with a porin to induce calcium ion transients in infected epithelial cells (Ayala et al, 2005b). Such calcium mediated signaling by pathogen invasion in neuronal cells is expected to increase ROS stress (Koedel and Pfister, 1999), through the calcium-mediated activation of neuronal NOS (Aoyagi et al, 2003).…”

Section: Ros and Pathogensmentioning

confidence: 99%

“…Recently, structures elucidated through a combination of cryo-electron microscopy and crystallography studies have revealed how type IV pilus fibers function, using surface groves as receptor-like binding sites for adherence and host cell interactions (Craig et al, 2006). This interaction, as part of the invasion process, is able to increase intracellular calcium bursts (Ayala et al, 2005b). Moreover, the pilus of Neisseria gonorrhoeae, which shares substantial sequence conservation with N. meningitides, acts cooperatively with a porin to induce calcium ion transients in infected epithelial cells (Ayala et al, 2005b).…”

Section: Ros and Pathogensmentioning

confidence: 99%

Developing master keys to brain pathology, cancer and aging from the structural biology of proteins controlling reactive oxygen species and DNA repair

2007

View full text Add to dashboard Cite

This review is focused on proteins with key roles in pathways controlling either reactive oxygen species or DNA damage responses, both of which are essential for preserving the nervous system. An imbalance of reactive oxygen species or inappropriate DNA damage response likely causes mutational or cytotoxic outcomes, which may lead to cancer and/or aging phenotypes. Moreover, individuals with hereditary disorders in proteins of these cellular pathways have significant neurological abnormalities. Mutations in a superoxide dismutase, which removes oxygen free radicals, may cause the neurodegenerative disease amyotrophic lateral sclerosis. Additionally, DNA repair disorders that affect the brain to varying extents include ataxia-telangiectasia-like disorder, Cockayne syndrome or Werner syndrome. Here, we highlight recent advances gained through structural biochemistry studies on enzymes linked to these disorders and other related enzymes acting within the same cellular pathways. We describe the current understanding of how these vital proteins coordinate chemical steps and integrate cellular signaling and response events. Significantly, these structural studies may provide a set of master keys to developing a unified understanding of the survival mechanisms utilized after insults by reactive oxygen species and genotoxic agents, and also provide a basis for developing an informed intervention in brain tumor and neurodegenerative disease progression.

show abstract

The pilus and porin of Neisseria gonorrhoeae cooperatively induce Ca2+ transients in infected epithelial cells

Cited by 23 publications

References 66 publications

Influence of type IV pilus retraction on the architecture of the Neisseria gonorrhoeae-infected cell cortex

Influence of type IV pilus retraction on the architecture of the Neisseria gonorrhoeae-infected cell cortex

Dynamics of Neisseria gonorrhoeae Attachment: Microcolony Development, Cortical Plaque Formation, and Cytoprotection

Developing master keys to brain pathology, cancer and aging from the structural biology of proteins controlling reactive oxygen species and DNA repair

Contact Info

Product

Resources

About