News

Human Papillomavirus (HPV) Upregulates the Cellular Deubiquitinase UCHL1 to Suppress the Keratinocyte's Innate Immune Response.

C Backendorf reports in PLOS Pathog.

Persistent infection of basal keratinocytes with high-risk human papillomavirus (hrHPV) may cause cancer. Keratinocytes are equipped with different pattern recognition receptors (PRRs) but hrHPV has developed ways to dampen their signals resulting in minimal inflammation and evasion of host immunity for sustained periods of time. To understand the mechanisms underlying hrHPV's capacity to evade immunity, we studied PRR signaling in non, newly, and persistently hrHPV-infected keratinocytes. We found that active infection with hrHPV hampered the relay of signals downstream of the PRRs to the nucleus, thereby affecting the production of type-I interferon and pro-inflammatory cytokines and chemokines.


Imaging protein three-dimensional nanocrystals with cryo-EM.

M van Heel M & JP Abrahams report in  Acta Crystallogr.

Flash-cooled three-dimensional crystals of the small protein lysozyme with a thickness of the order of 100 nm were imaged by 300 kV cryo-EM on a Falcon direct electron detector. The images were taken close to focus and to the eye appeared devoid of contrast. Fourier transforms of the images revealed the reciprocal lattice up to 3 Å resolution in favourable cases and up to 4 Å resolution for about half the crystals.


Snail and Slug, key regulators of TGF-β-induced EMT, are sufficient for the induction of single-cell invasion.

E Snaar-Jagalska reports in Biochem Biophys Res Commun.

TGF-β plays a dual role in cancer; in early stages it inhibits tumor growth, whereas later it promotes invasion and metastasis. TGF-β is thought to be pro-invasive by inducing epithelial-to-mesenchymal transition (EMT) via induction of transcriptional repressors, including Slug and Snail. In this study, we investigated the role of Snail and Slug in TGF-β-induced invasion in an in vitro invasion assay and in an embryonic zebrafish xenograft model.