Regulation of Hsp90 ATPase activity by the co-chaperone Cdc37p/p50cdc37

In vivo activation of client proteins by Hsp90 depends on its ATPase-coupled conformational cycle and on interaction with a variety of co-chaperone proteins. For some client proteins the co-chaperone Sti1/Hop/p60 acts as a "scaffold," recruiting Hsp70 and the bound client to Hsp90 early in the cycle and suppressing ATP turnover by Hsp90 during the loading phase. Recruitment of protein kinase clients to the Hsp90 complex appears to involve a specialized co-chaperone, Cdc37p/p50(cdc37), whose binding to Hsp90 is mutually exclusive of Sti1/Hop/p60. We now show that Cdc37p/p50(cdc37), like Sti1/Hop/p60, also suppresses ATP turnover by Hsp90 supporting the idea that client protein loading to Hsp90 requires a "relaxed" ADP-bound conformation. Like Sti1/Hop/p60, Cdc37p/p50(cdc37) binds to Hsp90 as a dimer, and the suppressed ATPase activity of Hsp90 is restored when Cdc37p/p50(cdc37) is displaced by the immunophilin co-chaperone Cpr6/Cyp40. However, unlike Sti1/Hop/p60, which can displace geldanamycin upon binding to Hsp90, Cdc37p/p50(cdc37) forms a stable complex with geldanamycin-bound Hsp90 and may be sequestered in geldanamycin-inhibited Hsp90 complexes in vivo.     

VIDA: a virus database system for the organization of animal virus genome open reading frames

VIDA is a new virus database that organizes open reading frames (ORFs) from partial and complete genomic sequences from animal viruses. Currently VIDA includes all sequences from GenBank for Herpesviridae, Coronaviridae and Arteriviridae. The ORFs are organized into homologous protein families, which are identified on the basis of sequence similarity relationships. Conserved sequence regions of potential functional importance are identified and can be retrieved as sequence alignments. We use a controlled taxonomical and functional classification for all the proteins and protein families in the database. When available, protein structures that are related to the families have also been included. The database is available for online search and sequence information retrieval at http://www.biochem.ucl.ac.uk/bsm/virus_database/ VIDA.html.     

Inflammation and lymphocyte activation during mycobacterial infection in the interferon-gamma-deficient mouse

Interferon-gamma is a pivotal cytokine in the protective response to tuberculosis. In its absence rampant bacterial growth results in tissue destruction and death. While macrophage activation is key, this pleiotropic cytokine has other secondary but significant roles. To investigate these roles, both intravenous and aerosol infection of the IFN-gamma gene disrupted (GKO) mouse was performed. For the first time we describe the very similar growth of bacteria, during the initial phase of infection, between control and GKO mice. During this initial phase, however, very different histopathologic consequences between control and GKO mice were observed. Key observations included an early increased accumulation of granulocytes and a much more rapid and pronounced interstitial pneumonia in the GKO mice. As infection developed, GKO mice mounted an antigen-specific response; however, lymphocyte activation was much more rapid in these mice. Of interest is the fact that this increased rapidity occurred prior to significant differences in bacterial number. Taken together these data support a role for IFN-gamma in limiting both initial cellular recruitment and acquired lymphocytic responses to mycobacterial infection. This role may be key in surviving the kind of chronic stimulatory disease caused by Mycobacterium tuberculosis.     

Detection of Escherichia coli in Foods: Indole Staining Methods for Cellulosic and Polysulfone Membrane Filters

Optimized procedures for staining Escherichia coli colonies on cellulosic and polysulfone membrane filters are described. An explanation for the behavior of the Ehrlich reaction on membrane filters is suggested.     

Non-native species impacts on pond occupancy by an anuran

Non-native fish and bullfrogs (Lithobates catesbeianus) are frequently cited as contributing to the decline of ranid frogs in the western United States, so we hypothesized that non-native species, habitat, or a combination of these relate to the probability of local extinction for northern red-legged frogs (Rana aurora) in Oregon, USA. We also hypothesized that the probability of colonization relates to land use, wetland size, or riparian forest. In a 5-yr study, we found no support for an effect of non-native species on northern red-legged frogs. Instead, probability of local extinction decreased with the extent of emergent vegetation and riparian forest. This finding suggests that managers consider the role of habitat when confronting non-native species problems. © 2010 The Wildlife Society.     

Penile revascularization in the treatment of vasculogenic impotence

Arterial insufficiency is the most common organic cause of impotence. The diagnosis can be established on a clinical basis through the use of Doppler probe evaluation of the penile pulses, penile blood pressure measuring, and nocturnal penile tumescence monitoring. The diagnosis may be confirmed by internal pudendal arteriography. Through microsurgical arterial revascularization, a 60 percent long-term success rate has been achieved. Two early and two late failures suggest the need for improved patient selection and confirm the progressive nature of the arteriosclerotic process.     

Structural basis for recruitment of BRCA2 by PALB2

The breast cancer 2, early onset protein (BRCA2) is central to the repair of DNA damage by homologous recombination. BRCA2 recruits the recombinase RAD51 to sites of damage, regulates its assembly into nucleoprotein filaments and thereby promotes homologous recombination. Localization of BRCA2 to nuclear foci requires its association with the partner and localizer of BRCA2 (PALB2), mutations in which are associated with cancer predisposition, as well as subtype N of Fanconi anaemia. We have determined the structure of the PALB2 carboxy‐terminal β‐propeller domain in complex with a BRCA2 peptide. The structure shows the molecular determinants of this important protein–protein interaction and explains the effects of both cancer‐associated truncating mutants in PALB2 and missense mutations in the amino‐terminal region of BRCA2.     

Epidemiology of training injuries in amateur taekwondo athletes: a retrospective cohort study

The objectives of this study were to estimate the incidence and describe the pattern and severity of training injuries in taekwondo, and to compare pattern and severity of training injuries with competition injuries. One hundred and fifty-two active Australian amateur taekwondo athletes, aged 12 years or over, completed an online survey comprising questions on training exposure and injury history over the preceding 12 months. The main outcome measures were: overall injury incidence rate per athlete-year; training injury incidence rate per athlete-year, per 1000 athlete-training-sessions, and per 1000 athlete-hours of training; injury severity; and injury proportions by anatomical region and by type of injury. Injury incidence rates were calculated with 95% confidence intervals using standard methods, while injury proportions were compared using Fisher''s exact test. The vast majority (81.5%) of taekwondo injuries in an average athlete-year occurred during training. The training injury incidence rate was estimated to be 1.6 (95% CI: 1.4, 1.9) per athlete-year, 11.8 (95% CI: 10.4, 13.4) per 1000 athlete-training-sessions, and 7.0 (95% CI: 6.1, 7.9) per 1000 athlete-hours of training. Among athletes with five or fewer injuries, the severity and injury pattern of training injuries were, by and large, the same as for competition injuries. Approximately sixty percent (60.3%) of training injuries required treatment by a health professional. Considering the burden of training injuries exceeds that of competition injuries, taekwondo governing bodies and stakeholders are encouraged to devote more efforts towards the identification of risk factors for, and prevention of, training injuries in the sport of taekwondo.