Thermotolerance Requires Refolding of Aggregated Proteins by Substrate Translocation through the Central Pore of ClpB

AbstractCell survival under severe thermal stress requires the activity of the ClpB (Hsp104) AAA+ chaperone that solubilizes and reactivates aggregated proteins in concert with the DnaK (Hsp70) chaperone system. How protein disaggregation is achieved and whether survival is solely dependent on ClpB-mediated elimination of aggregates or also on reactivation of aggregated proteins has been unclear. We engineered a ClpB variant, BAP, which associates with the ClpP peptidase and thereby is converted into a degrading disaggregase. BAP translocates substrates through its central pore directly into ClpP for degradation. ClpB-dependent translocation is demonstrated to be an integral part of the disaggregation mechanism. Protein disaggregation by the BAP/ClpP complex remains dependent on DnaK, defining a role for DnaK at early stages of the disaggregation reaction. The activity switch of BAP to a degrading disaggregase does not support thermotolerance development, demonstrating that cell survival during severe thermal stress requires reactivation of aggregated proteins

The GTPase ARFRP1 controls the lipidation of chylomicrons in the Golgi of the intestinal epithelium

The uptake and processing of dietary lipids by the small intestine is a multistep process that involves several steps including vesicular and protein transport. The GTPase ADP-ribosylation factor-related protein 1 (ARFRP1) controls the ARF-like 1 (ARL1)-mediated Golgi recruitment of GRIP domain proteins which in turn bind several Rab-GTPases. Here, we describe the essential role of ARFRP1 and its interaction with Rab2 in the assembly and lipidation of chylomicrons in the intestinal epithelium. Mice lacking Arfrp1 specifically in the intestine (Arfrp1vil−/−) exhibit an early post-natal growth retardation with reduced plasma triacylglycerol and free fatty acid concentrations. Arfrp1vil−/− enterocytes as well as Arfrp1 mRNA depleted Caco-2 cells absorbed fatty acids normally but secreted chylomicrons with a markedly reduced triacylglycerol content. In addition, the release of apolipoprotein A-I (ApoA-I) was dramatically decreased, and ApoA-I accumulated in the Arfrp1vil−/− epithelium, where it predominantly co-localized with Rab2. The release of chylomicrons from Caco-2 was markedly reduced after the suppression of Rab2, ARL1 and Golgin-245. Thus, the GTPase ARFRP1 and its downstream proteins are required for the lipidation of chylo­microns and the assembly of ApoA-I to these particles in the Golgi of intestinal epithelial cells

Vps20p and Vta1p interact with Vps4p and function in multivesicular body sorting and endosomal transport in Saccharomyces cerevisiae

Vps4p (End13p) is an AAA-family ATPase that functions in membrane transport through endosomes, sorting of soluble vacuolar proteins to the vacuole, and multivesicular body (MVB) sorting of membrane proteins to the vacuole lumen. In a yeast two-hybrid screen with Vps4p as bait we isolated VPS20 (YMR077c) and the novel open reading frame YLA181c, for which the name VTA1 has recently been assigned (Saccharomyces Genome Database). Vps4p directly binds Vps20p and Vta1p in vitro and binding is not dependent on ATP-conversely, Vps4p binding to Vps20p is partially sensitive to ATP hydrolysis. Both ATP binding [Vps4p-(K179A)] and ATP hydrolysis [Vps4p-(E233Q)] mutant proteins exhibit enhanced binding to Vps20p and Vta1p in vitro. The Vps4p-Vps20p interaction involves the coiled-coil domain of each protein, whereas the Vps4p-Vta1p interaction involves the (non-coiled-coil) C-terminus of each protein. Deletion of either VPS20 (vps20Delta) or VTA1 (vta1Delta) leads to similar class E Vps(-) phenotypes resembling those of vps4Delta, including carboxypeptidase Y (CPY) secretion, a block in ubiquitin-dependent MVB sorting, and a delay in both post-internalisation endocytic transport and biosynthetic transport to the vacuole. The vacuole resident membrane protein Sna3p (whose MVB sorting is ubiquitin-independent) does not appear to exit the class E compartment or reach the vacuole in cells lacking Vps20p, Vta1p or Vps4p, in contrast to other proteins whose delivery to the vacuole is only delayed. We propose that Vps20p and Vta1p regulate Vps4p function in vivo

Manipulation of Medicinal Products for Oral Administration to Paediatric Patients at a German University Hospital: An Observational Study

Pharmacotherapy in children requires medicinal products in age-appropriate dosage forms and flexible dose strengths. Healthcare professionals often encounter a lack of licensed and commercially available formulations, which results in the need for manipulation. This study aimed to investigate the nature, frequency and preventability of the manipulation of medicinal products before oral drug administration to paediatric inpatients in Germany. A prospective, direct observational approach was used. Two thousand and three medication preparation processes (MPP) in 193 patients were included in the analysis. Medicines were manipulated in 37% of oral administrations, affecting 57% of the patients. The percentage of manipulations was highest in infants/toddlers (42%) and lowest in adolescents (31%). Antiepileptics were most frequently manipulated (27%), followed by vitamins (20%) and drugs for acid-related disorders (13%). Fifty-six per cent of all manipulations were off-label. In 71% of these, no alternative appropriate medicinal product was commercially available. These results demonstrate that the manipulation of medicinal products before oral administration is common in paediatric wards in Germany. About half of the manipulations were off-label, indicating that no suitable formulation was available. Evidence-based guidelines for manipulations are required, with the overall aim of improving the safety of paediatric drug therapy

Metals and semi-metals in street soils of So Paulo city, Brazil

So Paulo is the largest city in Brazil and South America with about 20 million inhabitants in the metropolitan area, more than nine million motor vehicles and intense industrial activity, which are responsible for increasing pollution in the region. Nevertheless, little is known concerning metal and semi-metal content in the soils of this metropolitan region. This type of information could be extremely useful as a fingerprint of environmental pollution. The present study determined the elements As, Ba, Co, Cr, Sb, and Zn concentrations in soils adjacent to avenues of highly dense traffic in So Paulo city to assess their levels and possible sources. The analytical technique employed was Instrumental neutron activation analysis. The results showed, except for Co, concentration levels higher than the reference values for soils of So Paulo, according to the Environmental Protection Agency of the State of So Paulo guidelines. When compared to similar studies in other cities around the world, So Paulo soils presented higher levels, probably due to its high density traffic and industrial activity. The concentrations obtained for As and Cr indicate anthropogenic origin. The high levels of the traffic-related elements Ba, Sb, and Zn in soils nearby high density traffic avenues indicate they may originate from vehicular exhausts.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

Perioperative pain management models in four European countries: A narrative review of differences, similarities and future directions.

There is general agreement that acute pain management is an important component of perioperative medicine. However, there is no consensus on the best model of care for perioperative pain management, mainly because evidence is missing in many aspects. Comparing the similarities and differences between countries might reveal some insights into different organisational models and how they work. Here, we performed a narrative review to describe and compare the structures, processes and outcomes of perioperative pain management in the healthcare systems of four European countries using Donabedian's framework as a guide. Our comparison revealed many similarities, differences and gaps. Different structures of acute pain services in the four countries with no common definition and standards of care were found. Protocols have been implemented in all countries and guidelines in some. If outcome is assessed, it is mainly pain intensity, and many patients experiencing more intense pain than others have common risk factors (e.g. preoperative pain, preoperative opioid intake, female sex and young age). Outcome assessment beyond pain intensity (such as pain-related physical function, which is important for early rehabilitation and recovery) is currently not well implemented. Developing common quality indicators, a European guideline for perioperative pain management (e.g. for patients at high risk for experiencing severe pain and other outcome parameters) and common criteria for acute pain services might pave the way forward for improving acute pain management in Europe. Finally, the education of general and specialist staff should be aligned in Europe, for example, by using the curricula of European Pain Federation (EFIC)