The endoplasmic reticulum acts as a platform for ubiquitylated components of nuclear factor κB signaling.

The innate and adaptive immune responses involve the stimulation of nuclear factor κB (NF-κB) transcription factors through the Lys(63) (K(63))-linked ubiquitylation of specific components of NF-κB signaling pathways. We found that ubiquitylated components of the NF-κB pathway accumulated on the cytosolic leaflet of the endoplasmic reticulum (ER) membrane after the engagement of cell-surface, proinflammatory cytokine receptors or antigen receptors. Through mass spectrometric analysis, we found that the ER-anchored protein metadherin (MTDH) was a partner for these ubiquitylated activators of NF-κB and that it directly bound to K(63)-linked polyubiquitin chains.

Glioblastoma cell-secreted interleukin-8 induces brain endothelial cell permeability via CXCR2.

Glioblastoma constitutes the most aggressive and deadly of brain tumors. As yet, both conventional and molecular-based therapies have met with limited success in treatment of this cancer. Among other explanations, the heterogeneity of glioblastoma and the associated microenvironment contribute to its development, as well as resistance and recurrence in response to treatments.

Toxoplasma gondii actively remodels the microtubule network in host cells.

Toxoplasma gondii infection triggers host microtubule rearrangement and organelle recruitment around the parasite vacuole. Factors affecting initial stages of microtubule remodeling are unknown. To illuminate the mechanism, we tested the hypothesis that the parasite actively remodels host microtubules.

Toxoplasma gondii possesses a receptor for activated C kinase ortholog.

Receptor for activated C kinase 1 (RACK1) has been implicated in multiple protein-protein interactions including functioning as a scaffolding protein for signaling molecules. We report the cloning and cellular localization of a RACK1 ortholog (TgRACK1) in the opportunistic pathogen Toxoplasma gondii. The full-length transcript possesses a predicted ORF of 966 bp and codes for a protein of approximately 35 kDa molecular weight.

Molecular evolution of the vesicle coat component betaCOP in Toxoplasma gondii.

Coatomer coated (COPI) vesicles play a pivotal role for multiple membrane trafficking steps throughout the eukaryotic cell. Our focus is on betaCOP, one of the most well known components of the COPI multi-protein complex. Amino acid differences in betaCOP may dictate functional divergence across species during the course of evolution, especially with regards to the evolutionary pressures on obligate intracellular parasites.