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Uncoordinated 51-like kinase 2 (ULK2), a member of the serine/threonine kinase family, plays an essential role in the regulation of autophagy in mammalian cells. Given the role of autophagy in normal cellular homeostasis and in multiple diseases, improved mechanistic insight into this process may result in the development of novel therapeutic approaches. Here, we present evidence that ULK2 associates with karyopherin beta 2 (Kapβ2) for its transportation into the nucleus. We identify a potential PY-NLS motif (774gpgfgssppGaeaapslRyvPY795) in the S/P space domain of ULK2, which is similar to the consensus PY-NLS motif (R/K/H)X
2–5PY. Using a pull-down approach, we observe that ULK2 interacts physically with Kapβ2 both in vitro and in vivo. Confocal microscopy confirmed the co-localization of ULK2 and Kapβ2. Localization of ULK2 to the nuclear region was disrupted by mutations in the putative Kapβ2-binding motif (P794A). Furthermore, in transient transfection assays, the presence of the Kapβ2 binding site mutant (the cytoplasmic localization form) was associated with a substantial increase in autophagy activity (but a decrease in the in vitro serine-phosphorylation) compared with the wild type ULK2. Mutational analysis showed that the phosphorylation on the Ser1027 residue of ULK2 by Protein Kinase A (PKA) is the regulatory point for its functional dissociation from Atg13 and FIP 200, nuclear localization, and autophagy. Taken together, our observations indicate that Kapβ2 interacts with ULK2 through ULK2’s putative PY-NLS motif, and facilitates transport from the cytoplasm to the nucleus, depending on its Ser1027 residue phosphorylation by PKA, thereby reducing autophagic activity. 相似文献
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Nucleotide sequences of the small-subunit (SSU) ribosomal DNA were determined forPelvetia babingtonii, P. canaliculate, Pelvetiopsis limitata, andAscophyllum nodosum in the family Fucaceae. A total of 1755 positions were aligned for the whole sequence. The positional differences in the
primary structure among the taxa ranged from 16 to 30 nucleotide changes in pairwise comparisons. There was a minimum divergence
betweenPs. limitata andP. babingtonii while a maximum betweenPs. limitata andP. canaliculata. The SSU rDNA trees showed that the genusPelvetia was not monophyletic and the genusPelvetiopsis was not closely related toPelvetia. Our results suggest that the taxonomic revision of the genusPelvetia as well as the family Fucaceae is needed based on detailed morphological observations. 相似文献
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Menyanthes trifoliata is a threatened and endangered species in Korea and USA. To assess the important ecological characteristics for its conservation
and restoration, we measured the level of soluble reactive phosphorus (SRP) in the water, total N and C contents in the plants,
and the water-holding capacity of the surrounding floating peat mat. These factors, which limit the success of aquatic macrophytes,
were examined for their effects on the growth of this species. Leaflet areas and petiole lengths ranged from 6.1 cm2 and 12.4 cm, respectively, at a water depth of 5 cm, to 22.7 cm2 and 33.0 cm, respectively, at 40 cm. The peat mat was able to retain water at a depth of 5 to 45 cm. SRPs ranged from 10
to 46 ppb, while total C and N contents were between 0.62% (petiole) and 2.76% (leaf), and between 39.7% (petiole) and 43.8%
(stem), respectively. The water-holding level was not correlated with SRP, and neither phosphorus nor nitrogen content affected
plant growth. However, the capacity of the floating mat to hold water as the depth subsided was positively related to growth.
This suggests that such mats are good tools for restoring populations ofM. trifoliata when materials with high water-holding capacities are used. 相似文献
7.
Surface Plasmon Resonance Imaging-Based Protein Array Chip System for Monitoring a Hexahistidine-Tagged Protein during Expression and Purification 下载免费PDF全文
Hyeon-Su Ro Sun Ok Jung Byung Hoon Kho Hyung Pyo Hong Jae Sung Lee Yong-Beom Shin Min Gon Kim Bong Hyun Chung 《Applied microbiology》2005,71(2):1089-1092
A surface plasmon resonance imaging-based Ni2+-iminodiacetic acid-coated gold chip system was developed to enable specific detection of a hexahistidine-tagged recombinant protein in crude extracts or in column chromatography fractions. This system is especially advantageous for high-throughput analysis of multiple proteins. 相似文献
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Follicles are important in oocyte maturation. Successful estrous cycle requires remodeling of follicular cells, and proper execution of programmed cell death is crucial for normal follicular development. The objectives of the present study were to understand programmed cell death during follicle development, to analyze the differential follicle development patterns, and to assess the patterns of apoptosis and autophagy expression during follicle development in normal and miniature pigs. Through the analysis of differential patterns of programmed cell death during follicular development in porcine, MAP1LC3A, B and other autophagy-associated genes (ATG5, mTOR, Beclin-1) were found to increase in normal pigs, while it decreased in miniature pigs. However, for the apoptosis-associated genes, progression of genes during follicular development increased in miniature pigs, while it decreased in normal pigs. Thus, results show that normal and miniature pigs showed distinct patterns of follicular remodeling manifesting that programmed cell death largely depends on the types of pathway during follicular development (Type II or autophagy for normal pigs and Type I or apoptosis for miniature pigs). 相似文献
9.
Tyrosinase plays a pivotal role in the synthesis of melanin pigment synthesis on skin utilizing tyrosine as a substrate. Melanin is responsible for the protection against harmful ultraviolet irradiation, which can cause significant pathological conditions, such as skin cancers. However, it can also create esthetic problems when accumulated as hyperpigmented spots. Various skin-whitening ingredients which inhibit tyrosinase activity have been identified. Some of them, especially ones with natural product origins, possess phenolic moiety and have been employed in cosmetic products. Semi-synthetic and synthetic inhibitors have also been developed under inspiration of the natural inhibitors yet some of which have no phenolic groups. In this review, tyrosinase inhibitors with natural, semi-synthetic and synthetic origins are listed up with their structures, activities and characteristics. Further, a recent report on the adverse effect of a natural melanin synthesis inhibitor which was included in skin-whitening cosmetics is also briefly discussed. 相似文献
10.
Human astrocytic gliomas were studied with the freeze fracture technique. Orthogonal arrays of particles were noted in the plasma membranes of low-grade astrocytoma tissues. However, no such arrays were found in the plasma membranes of anaplastic glioma or glioblastoma tissues. Gap junctions were rarely seen in the membranes of these higher-grade gliomas; when seen, they consisted of relatively few particles in poorly organized plaques. These plasma membranes were dominated by randomly distributed single particles. These findings constitute aspects of the loss of differentiation in these malignant tumors. 相似文献