A pex1 missense mutation improves peroxisome function in a subset of Arabidopsis pex6 mutants without restoring PEX5 recycling.

Peroxisomes are eukaryotic organelles critical for plant and human development because they house essential metabolic functions, such as fatty acid ß-oxidation. The interacting ATPases PEX1 and PEX6 contribute to peroxisome function by recycling PEX5, a cytosolic receptor needed to import proteins targeted to the peroxisomal matrix. Arabidopsis pex6 mutants exhibit low PEX5 levels and defects in peroxisomal matrix protein import, oil body utilization, peroxisomal metabolism, and seedling growth. These defects are hypothesized to stem from impaired PEX5 retrotranslocation leading to PEX5 polyubiquitination and consequent degradation of PEX5 via the proteasome or of the entire organelle via autophagy. We recovered a pex1 missense mutation in a screen for second-site suppressors that restore growth to the pex6-1 mutant. Surprisingly, this pex1-1 mutation ameliorated the metabolic and physiological defects of pex6-1 without restoring PEX5 levels. Similarly, preventing autophagy by introducing an atg7-null allele partially rescued pex6-1 physiological defects without restoring PEX5 levels. atg7 synergistically improved matrix protein import in pex1-1 pex6-1, implying that pex1-1 improves peroxisome function in pex6-1 without impeding autophagy of peroxisomes (i.e., pexophagy). pex1-1 differentially improved peroxisome function in various pex6 alleles but worsened the physiological and molecular defects of a pex26 mutant, which is defective in the tether anchoring the PEX1-PEX6 hexamer to the peroxisome. Our results support the hypothesis that, beyond PEX5 recycling, PEX1 and PEX6 have additional functions in peroxisome homeostasis and perhaps in oil body utilization.

Disparate peroxisome-related defects in Arabidopsis pex6 and pex26 mutants link peroxisomal retrotranslocation and oil body utilization.

Catabolism of fatty acids stored in oil bodies is essential for seed germination and seedling development in Arabidopsis. This fatty acid breakdown occurs in peroxisomes, organelles that sequester oxidative reactions. Import of peroxisomal enzymes is facilitated by peroxins including PEX5, a receptor that delivers cargo proteins from the cytosol to the peroxisomal matrix. After cargo delivery, a complex of the PEX1 and PEX6 ATPases and the PEX26 tail-anchored membrane protein removes ubiquitinated PEX5 from the peroxisomal membrane. We identified Arabidopsis pex6 and pex26 mutants by screening for inefficient seedling ß-oxidation phenotypes. The mutants displayed distinct defects in growth, response to a peroxisomally metabolized auxin precursor, and peroxisomal protein import. The low PEX5 levels in these mutants were increased by treatment with a proteasome inhibitor or by combining pex26 with peroxisome-associated ubiquitination machinery mutants, suggesting that ubiquitinated PEX5 is degraded by the proteasome when the function of PEX6 or PEX26 is reduced. Combining pex26 with mutations that increase PEX5 levels either worsened or improved pex26 physiological and molecular defects, depending on the introduced lesion. Moreover, elevating PEX5 levels via a 35S:PEX5 transgene exacerbated pex26 defects and ameliorated the defects of only a subset of pex6 alleles, implying that decreased PEX5 is not the sole molecular deficiency in these mutants. We found peroxisomes clustered around persisting oil bodies in pex6 and pex26 seedlings, suggesting a role for peroxisomal retrotranslocation machinery in oil body utilization. The disparate phenotypes of these pex alleles may reflect unanticipated functions of the peroxisomal ATPase complex.

The PEX1 ATPase Stabilizes PEX6 and Plays Essential Roles in Peroxisome Biology.

A variety of metabolic pathways are sequestered in peroxisomes, conserved organelles that are essential for human and plant survival. Peroxin (PEX) proteins generate and maintain peroxisomes. The PEX1 ATPase facilitates recycling of the peroxisome matrix protein receptor PEX5 and is the most commonly affected peroxin in human peroxisome biogenesis disorders. Here, we describe the isolation and characterization of, to our knowledge, the first Arabidopsis (Arabidopsis thaliana) pex1 missense alleles: pex1-2 and pex1-3pex1-2 displayed peroxisome-related defects accompanied by reduced PEX1 and PEX6 levels. These pex1-2 defects were exacerbated by growth at high temperature and ameliorated by growth at low temperature or by PEX6 overexpression, suggesting that PEX1 enhances PEX6 stability and vice versa. pex1-3 conferred embryo lethality when homozygous, confirming that PEX1, like several other Arabidopsis peroxins, is essential for embryogenesis. pex1-3 displayed symptoms of peroxisome dysfunction when heterozygous; this semidominance is consistent with PEX1 forming a heterooligomer with PEX6 that is poisoned by pex1-3 subunits. Blocking autophagy partially rescued PEX1/pex1-3 defects, including the restoration of normal peroxisome size, suggesting that increasing peroxisome abundance can compensate for the deficiencies caused by pex1-3 and that the enlarged peroxisomes visible in PEX1/pex1-3 may represent autophagy intermediates. Overexpressing PEX1 in wild-type plants impaired growth, suggesting that excessive PEX1 can be detrimental. Our genetic, molecular, and physiological data support the heterohexamer model of PEX1-PEX6 function in plants.

The intrinsically disordered regions of the Drosophila melanogaster Hox protein ultrabithorax select interacting proteins based on partner topology.

Interactions between structured proteins require a complementary topology and surface chemistry to form sufficient contacts for stable binding. However, approximately one third of protein interactions are estimated to involve intrinsically disordered regions of proteins. The dynamic nature of disordered regions before and, in some cases, after binding calls into question the role of partner topology in forming protein interactions. To understand how intrinsically disordered proteins identify the correct interacting partner proteins, we evaluated interactions formed by the Drosophila melanogaster Hox transcription factor Ultrabithorax (Ubx), which contains both structured and disordered regions. Ubx binding proteins are enriched in specific folds: 23 of its 39 partners include one of 7 folds, out of the 1195 folds recognized by SCOP. For the proteins harboring the two most populated folds, DNA-RNA binding 3-helical bundles and α-α superhelices, the regions of the partner proteins that exhibit these preferred folds are sufficient for Ubx binding. Three disorder-containing regions in Ubx are required to bind these partners. These regions are either alternatively spliced or multiply phosphorylated, providing a mechanism for cellular processes to regulate Ubx-partner interactions. Indeed, partner topology correlates with the ability of individual partner proteins to bind Ubx spliceoforms. Partners bind different disordered regions within Ubx to varying extents, creating the potential for competition between partners and cooperative binding by partners. The ability of partners to bind regions of Ubx that activate transcription and regulate DNA binding provides a mechanism for partners to modulate transcription regulation by Ubx, and suggests that one role of disorder in Ubx is to coordinate multiple molecular functions in response to tissue-specific cues.

Nurses' knowledge and attitudes about pain in hospitalized patients.

PURPOSE: The purpose of the study was to measure knowledge and attitudes of nursing about pain management in patients before education, immediately after, and 6 months later. The end-point measure was Hospital Consumer Assessment of Healthcare Providers and Systems quarterly scores and percentile rank. DESIGN: This longitudinal, quasi-experimental, quantitative study used survey method with pretest and posttest scores to measure immediate learning and 6 months later to measure sustained changes in knowledge and attitudes for nurses in this facility. SETTING: The setting was a 360-bed acute care community hospital in the midsouth. SAMPLE: The sample consisted of approximately 206 bedside nurses who worked in an acute care facility and 164 final posttest participants. METHODS: The survey was used in a group setting immediately prior to a didactic learning experience. Immediately after the session, a posttest survey was administered. The 6-month follow-up occurred via an online module developed by the principal investigator. A repeated-measures analysis of variance, a pairwise comparison with a paired t test, and a Bonferroni correction were performed to determine if sustained knowledge and attitudes have changed. FINDINGS: Posttest scores were significantly higher than pretest scores on the Knowledge and Attitudes Survey Regarding Pain immediately after a didactic education session and 6 months later (P < .017). CONCLUSIONS: Six months later, scores remained higher than pretest or immediate posttest scores. IMPLICATIONS: Nurses with a stronger knowledge base may lead to better pain management, improved outcomes, and higher patient satisfaction scores.

Use of monetary and nonmonetary incentives to increase response rates among African Americans in the Wisconsin Pregnancy Risk Assessment Monitoring System.

From 2009 to 2010, an experiment was conducted to increase response rates among African American mothers in the Wisconsin Pregnancy Risk Assessment Monitoring System (PRAMS). Sample members were randomly assigned to groups that received a prepaid, cash incentive of $5 (n = 219); a coupon for diapers valued at $6 (n = 210); or no incentive (n = 209). Incentives were included with the questionnaire, which was mailed to respondents. We examined the effects of the incentives on several outcomes, including response rates, cost effectiveness, survey response distributions, and item nonresponse. Response rates were significantly higher for the cash group than for the coupon (42.5 vs. 32.4%, P < .05) or no incentive group (42.5 vs. 30.1%, P < .01); the coupon and no incentive groups performed similarly. While absolute costs were the highest for the cash group, the cost per completed survey was the lowest. The incentives had limited effects on response distributions for specific survey questions. Although respondents completing the survey by mail in the cash and coupon groups exhibited a trend toward being less likely to have missing data, the effect was not significant. Compared to a coupon or no incentive, a small cash incentive significantly improved response rates and was cost effective among African American respondents in Wisconsin PRAMS. Incentives had only limited effects, however, on survey response distributions, and no significant effects on item nonresponse.

Media composition influences yeast one- and two-hybrid results.

Although yeast two-hybrid experiments are commonly used to identify protein interactions, the frequent occurrence of false negatives and false positives hampers data interpretation. Using both yeast one-hybrid and two-hybrid experiments, we have identified potential sources of these problems: the media preparation protocol and the source of the yeast nitrogen base may not only impact signal range but also effect whether a result appears positive or negative. While altering media preparation may optimize signal differences for individual experiments, media preparation must be reported in detail to replicate studies and accurately compare results from different experiments.

Melhoria das Ações de Prevenção e Controle do Câncer de Colo Uterino e do Câncer de Mama na UBS Norton Vitorino Bohen, Acrelândia/AC

Resumo KIM, Alfredo Felix Gonzalez. Melhoria das Ações de Prevenção e Controle do Câncer de Colo Uterino e do Câncer de Mama na UBS Norton Vitorino Bohen, Acrelândia/AC. 2015. 67f. Trabalho de Conclusão de Curso (Curso de Especialização em Saúde da Família) - Departamento de Medicina Social, Faculdade de Medicina, Universidade Federal de Pelotas, Pelotas, 2015. O câncer de colo do útero apresenta-se como a segunda neoplasia maligna mais comum entre as mulheres no mundo e o de mama a terceira causa. No Brasil, as taxas de morbimortalidade por esses cânceres continuam elevadas, muito provavelmente porque as doenças ainda são diagnosticadas em estágios avançados. Ações de prevenção primária e detecção precoce de doenças são estratégias capazes de reduzir a morbimortalidade, de aumentar as chances de cura e melhorar a qualidade de vida. O controle dos cânceres do colo de útero e da mama depende de uma atenção básica qualificada e organizada, integrada com os demais níveis de atenção. Para tanto, realizou-se uma intervenção em 12 semanas, com o objetivo de melhorar o programa de prevenção e controle de câncer de colo uterino e de mama na Unidade Básica de Saúde Norton Vitorino Bohen, em Acrelândia, Estado do Acre. As metas planejadas consistiram em avaliar a cobertura das ações, a qualidade, a adesão das mulheres, o registro de informações, a avaliação de risco e a promoção de saúde. Os resultados foram longe do desejado, com baixas coberturas das ações às mulheres de 25 a 59 anos, o exame preventivo do câncer do útero alcançou 183 (20,7%) mulheres de 885 e de 50 a 69 anos com mamografias em dia foram quatro (1,9%) mulheres de 210, 180 (98,4%) mulheres com amostras satisfatórias do exame citopatológico. Entretanto, 67 (75,3%) mulheres tiveram avaliação dos sinais de alerta para o câncer de mama. A qualidade das coletas citopatológicas foi boa, 180 amostras de coleta citopatológicas foram satisfatórias (98,4%), a adesão das mulheres à realização de exame citopatológico de colo de útero e mamografia e a promoção de saúde foram importantes. Com a intervenção a equipe adquiriu conhecimento do protocolo da prevenção e controle de câncer de colo uterino e câncer de mama, envolveu-se mais em qualquer instância do processo assistencial e foram mais conscientes da importância de sua atuação e da necessidade de aliarem o conhecimento técnico específico ao compromisso com um resultado satisfatório da atenção, levando o significado desse resultado para cada mulher. Palavras-chave: atenção primária à saúde; saúde da família; saúde da mulher; programas de rastreamento; neoplasias do colo do útero; neoplasias da mama.