Functional Analysis of the Phycomyces carRA Gene Encoding the Enzymes Phytoene Synthase and Lycopene Cyclase

Phycomyces carRA gene encodes a protein with two domains. Domain R is characterized by red carR mutants that accumulate lycopene. Domain A is characterized by white carA mutants that do not accumulate significant amounts of carotenoids. The carRA-encoded protein was identified as the lycopene cyclase and phytoene synthase enzyme by sequence homology with other proteins. However, no direct data showing the function of this protein have been reported so far. Different Mucor circinelloides mutants altered at the phytoene synthase, the lycopene cyclase or both activities were transformed with the Phycomyces carRA gene. Fully transcribed carRA mRNA molecules were detected by Northern assays in the transformants and the correct processing of the carRA messenger was verified by RT-PCR. These results showed that Phycomyces carRA gene was correctly expressed in Mucor. Carotenoids analysis in these transformants showed the presence of ß-carotene, absent in the untransformed strains, providing functional evidence that the Phycomyces carRA gene complements the M. circinelloides mutations. Co-transformation of the carRA cDNA in E. coli with different combinations of the carotenoid structural genes from Erwinia uredovora was also performed. Newly formed carotenoids were accumulated showing that the Phycomyces CarRA protein does contain lycopene cyclase and phytoene synthase activities. The heterologous expression of the carRA gene and the functional complementation of the mentioned activities are not very efficient in E. coli. However, the simultaneous presence of both carRA and carB gene products from Phycomyces increases the efficiency of these enzymes, presumably due to an interaction mechanism

Mapping the prion protein distribution in marsupials: insights from comparing opossum with mouse CNS

The cellular form of the prion protein (PrP(C)) is a sialoglycoprotein widely expressed in the central nervous system (CNS) of mammalian species during neurodevelopment and in adulthood. The location of the protein in the CNS may play a role in the susceptibility of a species to fatal prion diseases, which are also known as the transmissible spongiform encephalopathies (TSEs). To date, little is known about PrP(C) distribution in marsupial mammals, for which no naturally occurring prion diseases have been reported. To extend our understanding of varying PrP(C) expression profiles in different mammals we carried out a detailed expression analysis of PrP(C) distribution along the neurodevelopment of the metatherian South American short-tailed opossum (Monodelphis domestica). We detected lower levels of PrP(C) in white matter fiber bundles of opossum CNS compared to mouse CNS. This result is consistent with a possible role for PrP(C) in the distinct neurodevelopment and neurocircuitry found in marsupials compared to other mammalian species

Light regulation of metabolic pathways in fungi

Light represents a major carrier of information in nature. The molecular machineries translating its electromagnetic energy (photons) into the chemical language of cells transmit vital signals for adjustment of virtually every living organism to its habitat. Fungi react to illumination in various ways, and we found that they initiate considerable adaptations in their metabolic pathways upon growth in light or after perception of a light pulse. Alterations in response to light have predominantly been observed in carotenoid metabolism, polysaccharide and carbohydrate metabolism, fatty acid metabolism, nucleotide and nucleoside metabolism, and in regulation of production of secondary metabolites. Transcription of genes is initiated within minutes, abundance and activity of metabolic enzymes are adjusted, and subsequently, levels of metabolites are altered to cope with the harmful effects of light or to prepare for reproduction, which is dependent on light in many cases. This review aims to give an overview on metabolic pathways impacted by light and to illustrate the physiological significance of light for fungi. We provide a basis for assessment whether a given metabolic pathway might be subject to regulation by light and how these properties can be exploited for improvement of biotechnological processes

Caracterização vocal de pacientes com hipertireoidismo e hipotireoidismo Vocal characterization of patients with hyperthyroidism and hypothyroidism

OBJETIVO: Caracterizar a qualidade vocal, por meio de análise computadorizada e perceptivo-auditiva, de pacientes com hipertireoidismo (grupo A) e hipotireoidismo (grupo B). MÉTODOS: Vinte mulheres não fumantes, com idades entre 18 e 55 anos, atendidas no Ambulatório de Endocrinologia da instituição, foram avaliadas após o diagnóstico clínico e laboratorial de hipertireoidismo ou hipotireoidismo. Os parâmetros investigados foram: tempo da doença, presença de queixa vocal, tempos máximos de fonação /a/, /s/ e /z/, freqüência fundamental (F0), ruído glótico (GNE). Os aspectos avaliados na análise perceptivo-auditiva, foram: coordenação pneumo-fonoarticulatória (coordenada ou incoordenada), pitch, loudness, ataque vocal, ressonância, velocidade de fala e qualidade vocal, que poderia ter até duas das seguintes classificações: neutra, rouca, soprosa, áspera ou tensa, e grau: leve, moderado ou severo. Os dados foram tabulados e analisados estatisticamente através do programa EPI-INFO 6.04b, método qualitativo Fisher, com nível de significância menor do que 0.05. RESULTADOS: A análise perceptivo-auditiva mostrou que sete pacientes hipotireoideos e nove pacientes hipertireoideos apresentaram alteração na qualidade vocal. Oito pacientes em ambos os grupos apresentaram incoordenação pneumo-fonoarticulatória. Oito pacientes do grupo A e seis pacientes do grupo B referiam queixas vocais como rouquidão e voz grossa, respectivamente. Na análise acústica, nove pacientes apresentaram o ruído glótico alterado. CONCLUSÃO: Os resultados evidenciaram grande incidência de alteração vocal nos grupos estudados (grupos dos pacientes com hipertireoidismo e com hipotireoidismo), o que demonstra a relação entre disfonia e disfunções tireoideanas.<br>PURPOSE: To characterize the vocal quality of subjects with hyperthyroidism (group A), and hypothyroidism (group B) through a computer-aided and auditory-perceptive analysis. METHODS: Twenty non-smoking women with ages between 18 and 55 years from the Endocrinology Ambulatory of the institution were evaluated after clinical and lab diagnosis for hyperthyroidism or hypothyroidism. The parameters investigated were: period bearing the disease, vocal complaint, maximum phonation time /a/, /s/, and /z/, fundamental frequency (F0), glottal noise (GNE). The aspects evaluated in the auditory-perceptive analysis were: pneumo-phono-articulatory coordination (coordinated or uncoordinated), pitch, loudness, vocal attack, resonance, speech speed and vocal quality, that could be classified as one or two of the following: neutral, hoarse, whispered, coarse, or tense, and degree: light, moderate or severe. Data were statistically analyzed through the EPI-INFO 6.04b software, Fisher qualitative method, considering a significance level of 0.05. RESULTS: The auditory-perceptive analysis showed that seven patients with hypothyroidism and nine with hyperthyroidism presented changes in vocal quality. Eight subjects from both groups presented pneumo-phono-articulatory incoordination. Eight subjects from group A and six from group B referred vocal complaints, such as hoarseness and thick voice, respectively. In the acoustic analysis, nine subjects presented change in glottal noise. CONCLUSION: The results showed great incidence of vocal changes on the studied groups (both hyper and hypothyroidism groups), which evidences the relation between dysphonia and thyroidal dysfunctions