RESUMEN
Although prior research predicts mainly that followers expect leaders to exert less paternalistic control (such as emphasis on discipline, didactic instruction, and belittling followers), we argue that such an expectation may not be stable overtime or across settings. Based on the connectionist perspectives of implicit leadership theories, we propose a follower expectation model of paternalistic control, in which followers compare their perceived with expected levels of paternalistic control. Two inconsistent conditions-insufficient and excessive control-are identified, and the consistency between perceived and expected paternalistic control is predicted to relate to favorable follower outcomes. We examine this model by conducting two daily experience sampling studies in Taiwan. Our findings indicate that insufficient control is as unfavorable as excessive control in lowering followers' job satisfaction and citizenship behavior, and this pattern is particularly salient in terms of emphasis on discipline and the belittling of followers. A supplemental, qualitative analysis additionally demonstrated the conditions under which the expectation-perception consistency regarding belittling followers relates to favorable follower responses. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
RESUMEN
The present study used the endpoint of hypothermia to investigate opioid and neuropeptide FF (NPFF) interactions in conscious animals. Both opioid and NPFF systems played important roles in thermoregulation, which suggested a link between opioid receptors and NPFF receptors in the production of hypothermia. Therefore, we designed a study to investigate the relationship between opioid and NPFF in control of thermoregulation in mice. The selective NPFF receptors antagonist RF9 (30nmol) injected into the third ventricle failed to induce significant effect, but it completely antagonized the hypothermia of NPFF (45 nmol) after cerebral administration in mice. In addition, RF9 (30 nmol) co-injected i.c.v. in the third ventricle reduced the hypothermia induced by morphine (5nmol,) or nociceptin/orphanin FQ (N/OFQ) (2 nmol). Neither the classical opioid receptors antagonist naloxone (10 nmol) nor NOP receptor antagonist [Nphe(1)]NC(1-13)NH(2) (7.5 nmol) reduced the hypothermia induced by the central injection of NPFF at dose of 45 nmol. Co-injected with a low dose of NPFF (5 nmol), the hypothermia of morphine (5 nmol) or N/OFQ (2 nmol) was not modified. These results suggest that NPFF receptors activation is required for opioid to produce hypothermia. In contrast, NPFF-induced hypothermia is mainly mediated by its own receptors, independent of opioid receptors in the mouse brain. This interaction, quantitated in the present study, is the first evidence that NPFF receptors mediate opioid-induced hypothermia in conscious animals.
Asunto(s)
Adamantano/análogos & derivados , Analgésicos Opioides/farmacología , Regulación de la Temperatura Corporal/efectos de los fármacos , Dipéptidos/farmacología , Receptores de Neuropéptido/antagonistas & inhibidores , Adamantano/farmacología , Animales , Área Bajo la Curva , Interacciones Farmacológicas , Hipotermia/inducido químicamente , Hipotermia/metabolismo , Cinética , Masculino , Ratones , Morfina/farmacología , Naloxona/farmacología , Péptidos Opioides/farmacología , NociceptinaRESUMEN
Fusion tag is one of the best available tools to date for enhancement of the solubility or improvement of the expression level of recombinant proteins in Escherichia coli. Typically, two consecutive affinity purification steps are often necessitated for the purification of passenger proteins. As a fusion tag, acyl carrier protein (ACP) could greatly increase the soluble expression level of Glucokinase (GlcK), α-Amylase (Amy) and GFP. When fusion protein ACP-G2-GlcK-Histag and ACP-G2-Amy-Histag, in which a protease TEV recognition site was inserted between the fusion tag and passenger protein, were coexpressed with protease TEV respectively in E. coli, the efficient intracellular processing of fusion proteins was achieved. The resulting passenger protein GlcK-Histag and Amy-Histag accumulated predominantly in a soluble form, and could be conveniently purified by one-step Ni-chelating chromatography. However, the fusion protein ACP-GFP-Histag was processed incompletely by the protease TEV coexpressed in vivo, and a large portion of the resulting target protein GFP-Histag aggregated in insoluble form, indicating that the intracellular processing may affect the solubility of cleaved passenger protein. In this context, the soluble fusion protein ACP-GFP-Histag, contained in the supernatant of E. coli cell lysate, was directly subjected to cleavage in vitro by mixing it with the clarified cell lysate of E. coli overexpressing protease TEV. Consequently, the resulting target protein GFP-Histag could accumulate predominantly in a soluble form, and be purified conveniently by one-step Ni-chelating chromatography. The approaches presented here greatly simplify the purification process of passenger proteins, and eliminate the use of large amounts of pure site-specific proteases.
Asunto(s)
Cromatografía de Afinidad/métodos , Proteínas Recombinantes de Fusión/aislamiento & purificación , Endopeptidasas/biosíntesis , Endopeptidasas/genética , Endopeptidasas/aislamiento & purificación , Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Glucoquinasa/biosíntesis , Glucoquinasa/genética , Glucoquinasa/aislamiento & purificación , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes/síntesis química , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Solubilidad , alfa-Amilasas/biosíntesis , alfa-Amilasas/genética , alfa-Amilasas/aislamiento & purificaciónRESUMEN
The correct folding of a protein is a pre-requirement for its proper posttranslational modification. The Escherichia coli Sec pathway, in which preproteins, in an unfolded, translocation-competent state, are rapidly secreted across the cytoplasmic membrane, is commonly assumed to be unfavorable for their modification in the cytosol. Whether posttranslationally modified recombinant preproteins can be efficiently transported via the Sec pathway, however, remains unclear. ACP and BCCP domain (BCCP87) are carrier proteins that can be converted into active phosphopantetheinylated ACP (holo-ACP) and biotinylated-BCCP (holo-BCCP) by AcpS and BirA, respectively. In the present study, we show that, when ACP or BCCP87 is fused to the C-terminus of secretory protein YebF or MBP, the resulting fusion protein preYebF-ACP, preYebF-BCCP87, preMBP-ACP or preMBP-BCCP87 can be modified and then secreted. Our data demonstrate that posttranslational modification of preYebF-ACP, preYebF-BCCP87 preMBP-ACP and preMBP-BCCP87 can take place in the cytosol prior to translocation, and the Sec machinery accommodates these previously modified fusion proteins. High levels of active holo-ACP and holo-BCCP87 are achieved when AcpS or BirA is co-expressed, especially when sodium azide is used to retard their translocation across the inner membrane. Our results also provide an alternative to achieve a high level of modified recombinant proteins expressed extracellularly.
Asunto(s)
Escherichia coli/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Acetil-CoA Carboxilasa/genética , Proteína Transportadora de Acilo/genética , Citosol/metabolismo , Escherichia coli/citología , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Espacio Extracelular/metabolismo , Acido Graso Sintasa Tipo II/genética , Procesamiento Proteico-Postraduccional , Transporte de Proteínas , Proteínas Recombinantes de Fusión/genéticaRESUMEN
The endogenous opioid system has been found to be involved in the fever caused by lipopolysaccharide (LPS). Neuropeptide FF (NPFF, FLFQPQRF-NH(2)) is an endogenous peptide known to modulate opioid activity, mainly in the central nervous system. Therefore, those data suggested a link between LPS-induced fever and NPFF systems. Using a model of acute neuroinflammation, we sought to determine the effects of NPFF systems on the fever induced by i.c.v. injection of LPS. Coinjected with different doses of NPFF (10 and 30 nmol), the fever of LPS (125 ng) was not modified. Interestingly, the selective NPFF receptors antagonist RF9 (30 nmol) injected into the third ventricle failed to induce significant effect, but it decreased the fever of LPS (125 ng) after cerebral administration in mice. These results suggest that NPFF receptors activation is required for LPS to produce fever. This interaction is the first evidence that NPFF systems participate in the control of acute neuroinflammation in conscious animals.