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51.
Patrícia Picciarelli-Lima André G Oliveira Adelina M Reis Evanguedes Kalapothakis Germán AB Mahecha Rex A Hess Cleida A Oliveira 《Reproductive biology and endocrinology : RB&E》2006,4(1):51-10
Background
Fluid homeostasis is critical for normal function of the male reproductive tract and aquaporins (AQP) play an important role in maintenance of this water and ion balance. Several AQPs have been identified in the male, but their regulation is not fully comprehended. Hormonal regulation of AQPs appears to be dependent on the steroid in the reproductive tract region. AQP9 displays unique hormonal regulation in the efferent ductules and epididymis, as it is regulated by both estrogen and dihydrotestosterone (DHT) in the efferent ductules, but only by DHT in the initial segment epididymis. Recent data have shown that a metabolite of DHT, 5-alpha-androstane-3-beta-17-beta-diol (3-beta-diol), once considered inactive, is also present in high concentrations in the male and indeed has biological activity. 3-beta-diol does not bind to the androgen receptor, but rather to estrogen receptors ER-alpha and ER-beta, with higher affinity for ER-beta. The existence of this estrogenic DHT metabolite has raised the possibility that estradiol may not be the only estrogen to play a major role in the male reproductive system. Considering that both ER-alpha and ER-beta are highly expressed in efferent ductules, we hypothesized that the DHT regulation of AQP9 could be due to the 3-beta-diol metabolite. 相似文献52.
本文综述了香菇(Lentinula edodes)的分类历史,确认其在蘑菇目(Agaricales)Tricholomataceae科下的分类地位,并证实了它与多孔菌目(Poriales)Lentinaceae科的Lentinus属没有联系。根据《真菌、地衣汉语学名命名法规》,作者讨论了译为“香菇属”的Lentinus和“小香菇属”的Lentinellus两属的汉语学名问题,提出Lentinus的汉语学名应订正为“韧伞属”,Lentinellus为“螺壳菌属”。香菇所在的Lentinula属的汉语学名建议为“木菇属”。 相似文献
53.
Radim Cegan Gabriel AB Marais Hana Kubekova Nicolas Blavet Alex Widmer Boris Vyskot Jaroslav Doležel Jan Šafář Roman Hobza 《BMC plant biology》2010,10(1):180
Background
The evolution of sex chromosomes is often accompanied by gene or chromosome rearrangements. Recently, the gene AP3 was characterized in the dioecious plant species Silene latifolia. It was suggested that this gene had been transferred from an autosome to the Y chromosome. 相似文献54.
Sandra I Vieira Sandra Rebelo Hermann Esselmann Jens Wiltfang James Lah Rachel Lane Scott A Small Sam Gandy Edgar F da Cruz e Silva Odete AB da Cruz e Silva 《Molecular neurodegeneration》2010,5(1):1-21
Background
Retrograde transport of several transmembrane proteins from endosomes to the trans-Golgi network (TGN) occurs via Rab 5-containing endosomes, mediated by clathrin and the recently characterized retromer complex. This complex and one of its putative sorting receptor components, SorLA, were reported to be associated to late onset Alzheimer's disease (AD). The pathogenesis of this neurodegenerative disorder is still elusive, although accumulation of amyloidogenic Abeta is a hallmark. This peptide is generated from the sucessive β- and γ- secretase proteolysis of the Alzheimer's amyloid precursor protein (APP), events which are associated with endocytic pathway compartments. Therefore, APP targeting and time of residence in endosomes would be predicted to modulate Abeta levels. However, the formation of an APP- and retromer-containing protein complex with potential functions in retrieval of APP from the endosome to the TGN had, to date, not been demonstrated directly. Further, the motif(s) in APP that regulate its sorting to the TGN have not been characterized.Results
Through the use of APP-GFP constructs, we show that APP containing endocytic vesicles targeted for the TGN, are also immunoreactive for clathrin-, Rab 5- and VPS35. Further, they frequently generate protruding tubules near the TGN, supporting an association with a retromer-mediated pathway. Importantly, we show for the first time, that mimicking APP phosphorylation at S655, within the APP 653YTSI656 basolateral motif, enhances APP retrieval via a retromer-mediated process. The phosphomimetic APP S655E displays decreased APP lysosomal targeting, enhanced mature half-life, and decreased tendency towards Abeta production. VPS35 downregulation impairs the phosphorylation dependent APP retrieval to the TGN, and decreases APP half-life.Conclusions
We reported for the first time the importance of APP phosphorylation on S655 in regulating its retromer-mediated sorting to the TGN or lysosomes. Significantly, the data are consistent with known interactions involving the retromer, SorLA and APP. Further, these findings add to our understanding of APP targeting and potentially contribute to our knowledge of sporadic AD pathogenesis representing putative new targets for AD therapeutic strategies. 相似文献55.
Fanni Aspetsberger Matthias Zabel Timothy Ferdelman Ulrich Struck Andreas Mackensen Astrid Ahke Ursula Witte - Present address: University of Aberdeen Aberdeen AB TZ UK 《Marine Biology Research》2007,3(5):342-356
The benthic community in continental slope and deep-sea sediments of the Benguela Upwelling System was supplied with 13C-labelled organic matter (OM) of two different qualities using a benthic chamber lander. Freeze-dried cultures of Skeletonema costatum served as 'fresh' OM. 'Altered' OM of the same material had been additionally dialysed to remove low-molecular weight compounds. In order to investigate the benthic response pattern, mineralization of labelled OM, uptake by macrofauna and incorporation into bacteria were followed over 18-36 h. Total oxygen uptake was not affected beyond natural variation by the OM addition. Mineralization dominated the 13C-labelled phytodetritus processing, constituting 71-95% of the total processed OM. Bacterial incorporation of phytodetrital carbon exceeded macrofaunal uptake at all stations. Stations situated in a major centre of OM deposition showed phytodetritus processing rates on average twice as high as outside the depocentre. Phytodetritus processing was 1.5, 2.5 and 4.3 times higher for fresh than for altered OM at 605, 1019 and 1335 m water depth, respectively. Our observations clearly indicate the importance of OM quality on mineralization rates. 相似文献
56.
Therien Denis AB Hou Renjie Lagugné-Labarthet François 《Plasmonics (Norwell, Mass.)》2020,15(2):507-515
Plasmonics - Nanostructured conductive surfaces have been exploited for a variety of applications in photonics and optical sensing due to the broad spectral tunability of the localized surface... 相似文献
57.
Ultrastructure of the sodium pump: Comparison of thin sectioning, negative staining, and freeze-fracture of purified, membrane-bound (Na+, K+)-ATPase 下载免费PDF全文
Purified (Na+, K+)-ATPase was studied by electron microscopy after thin sectioning, negative staining, and freeze-fracturing, particular emphasis being paid to the dimensions and frequencies of substructures in the membranes. Ultrathin sections show exclusively flat or cup-shaped membrane fragments which are triple-layered along much of their length and have diameters of 0.1-0.6 μm. Negative staining revealed a distinct substructure of particles with diameters between 30 and 50 A and with a frequency of 12,500 +/- 2,400 (SD) per μm(2). Comparisons with sizes of the protein components suggest that each surface particle contains as its major component one large catalytic chain with mol wt close to 100,000 and that two surface particles unite to form the unit of (Na+,K+)-ATPase which binds one molecule of ATP or ouabain. The further observations that the surface particles protrude from the membrane surface and are observed on both membrane surfaces in different patterns and degrees of clustering suggest that protein units span the membrane and are capable of lateral mobility. Freeze-fracturing shows intramembranous particles with diameters of 90-110 A and distributed on both concave and convex fracture faces with a frequency of 3,410 +/- 370 per μm(2) and 390 +/- 170 per μm(2), respectively. The larger diameters and three to fourfold smaller frequency of the intramembranous particles as compared to the surface particles seen after negative staining may reflect technical differences between methods, but it is more likely that the intramembranous particle is an oliogomer composed of two or even more of the protein units which form the surface particles. 相似文献
58.
The paper is devoted to a taxonomic revision of the genus Sensillonychiurus Pomorski & Sveenkova, 2006. Five new species of this genus, i.e. Sensillonychiurus mirussp. n., Sensillonychiurus taimyrensissp. n., Sensillonychiurus vegaesp. n., Sensillonychiurus vitimicussp. n., and Sensillonychiurus amuricussp. n., as well as three new species of the related genus Allonychiurus Yoshii, 1995, i.e. Allonychiurus subvolinensissp. n., Allonychiurus elikoniussp. n., and Allonychiurus unisetosussp. n. are being described from various regions of Eurasia. The diagnoses of both genera are amended to include described species. Two genera, Tantulonychiurus Pomorski, 1996 and Thibaudichiurus Weiner, 1996, are treated as junior synonyms of the genus Allonychiurus. Agraphorura eisi (Rusek, 1976) is transferred to Sensillonychiurus; Tantulonychiurus volinensis (Szeptycki, 1964) and Tantulonychiurus asiaticus Babenko, 2007 to Allonychiurus. A review of morphological peculiarities of Sensillonychiurus is performed, comparisons with the other genera of Thalassaphorurini given, and a key to the known species provided. 相似文献
59.
Lucy Rutten Cecile Ribot Blanca Trejo-Aguilar Han AB Wösten Ronald P de Vries 《BMC microbiology》2009,9(1):166-7
Background
L-arabitol dehydrogenase (LAD) and xylitol dehydrogenase (XDH) are involved in the degradation of L-arabinose and D-xylose, which are among the most abundant monosaccharides on earth. Previous data demonstrated that LAD and XDH not only differ in the activity on their biological substrate, but also that only XDH has significant activity on D-sorbitol and may therefore be more closely related to D-sorbitol dehydrogenases (SDH). In this study we aimed to identify residues involved in the difference in substrate specificity. 相似文献60.
Wanessa LF Tavares Gleidice E Lavalle Mariana S Figueiredo Aline G Souza Angelica C Bertagnolli Fernando AB Viana Paulo RO Paes Rubens A Carneiro Guilherme AO Cavalcanti Marilia M Melo Geovanni D Cassali 《Acta veterinaria Scandinavica》2010,52(1):1-6