排序方式: 共有27条查询结果,搜索用时 15 毫秒
1.
Michelle E. LeBlanc Weiwen Wang Nora B. Caberoy Xiuping Chen Feiye Guo Gabriela Alvarado Chen Shen Feng Wang Hui Wang Rui Chen Zhao-Jun Liu Keith Webster Wei Li 《PloS one》2015,10(5)
Hepatoma-derived growth factor-related protein-3 (Hdgfrp3 or HRP-3) was recently reported as a neurotrophic factor and is upregulated in hepatocellular carcinoma to promote cancer cell survival. Here we identified HRP-3 as a new endothelial ligand and characterized its in vitro and in vivo functional roles and molecular signaling. We combined open reading frame phage display with multi-round in vivo binding selection to enrich retinal endothelial ligands, which were systematically identified by next generation DNA sequencing. One of the identified endothelial ligands was HRP-3. HRP-3 expression in the retina and brain was characterized by Western blot and immunohistochemistry. Cell proliferation assay showed that HRP-3 stimulated the growth of human umbilical vein endothelial cells (HUVECs). HRP-3 induced tube formation of HUVECs in culture. Wound healing assay indicated that HRP-3 promoted endothelial cell migration. HRP-3 was further confirmed for its in vitro angiogenic activity by spheroid sprouting assay. HRP-3 extrinsically activated the extracellular-signal-regulated kinase ½ (ERK1/2) pathway in endothelial cells. The angiogenic activity of HRP-3 was independently verified by mouse cornea pocket assay. Furthermore, in vivo Matrigel plug assay corroborated HRP-3 activity to promote new blood vessel formation. These results demonstrated that HRP-3 is a novel angiogenic factor. 相似文献
2.
CbgA, a protein involved in cortex formation and stress resistance in Myxococcus xanthus spores 下载免费PDF全文
Tengra FK Dahl JL Dutton D Caberoy NB Coyne L Garza AG 《Journal of bacteriology》2006,188(23):8299-8302
CbgA plays a role in cortex formation and the acquisition of a subset of stress resistance properties in Myxococcus xanthus spores. The cbgA mutant produces spores with thin or no cortex layers, and these spores are more sensitive to heat and sodium dodecyl sulfate than their wild-type counterparts. 相似文献
3.
Phagocytosis of apoptotic cells and cellular debris is a critical process of maintaining tissue and immune homeostasis. Defects in the phagocytosis process cause autoimmunity and degenerative diseases. Phagocytosis ligands or "eat-me" signals control the initiation of the process by linking apoptotic cells to receptors on phagocyte surface and triggering signaling cascades for cargo engulfment. Eat-me signals are traditionally identified on a case-by-case basis with challenges, and the identification of their cognate receptors is equally daunting. Here, we identified galectin-3 (Gal-3) as a new MerTK ligand by an advanced dual functional cloning strategy, in which phagocytosis-based functional cloning is combined with receptor-based affinity cloning to directly identify receptor-specific eat-me signal. Gal-3 interaction with MerTK was independently verified by co-immunoprecipitation. Functional analyses showed that Gal-3 stimulated the phagocytosis of apoptotic cells and cellular debris by macrophages and retinal pigment epithelial cells with MerTK activation and autophosphorylation. The Gal-3-mediated phagocytosis was blocked by excessive soluble MerTK extracellular domain and lactose. These results suggest that Gal-3 is a legitimate MerTK-specific eat-me signal. The strategy of dual functional cloning with applicability to other phagocytic receptors will facilitate unbiased identification of their unknown ligands and improve our capacity for therapeutic modulation of phagocytic activity and innate immune response. 相似文献
4.
Replication slippage may cause parallel evolution in the secondary structures of mitochondrial transfer RNAs 总被引:9,自引:4,他引:5
Presence of the dihydrouridine (D) stem in the mitochondrial cysteine tRNA
is unusually variable among lepidosaurian reptiles. Phylogenetic and
comparative analyses of cysteine tRNA gene sequences identify eight
parallel losses of the D-stem, resulting in D-arm replacement loops.
Sampling within the monophyletic Acrodonta provides no evidence for
reversal. Slipped-strand mispairing of noncontiguous repeated sequences
during replication or direct replication slippage can explain repeats
observed within cysteine tRNAs that contain a D-arm replacement loop. These
two mechanisms involving replication slippage can account for the loss of
the cysteine tRNA D-stem in several lepidosaurian lineages, and may
represent general mechanisms by which the secondary structures of
mitochondrial tRNAs are altered.
相似文献
5.
The complete cDNA sequence and protein reading frame of a developmentally
regulated hemocyanin subunit in the Dungeness crab (Cancer magister) is
presented. The protein sequence is aligned with 18 potentially homologous
hemocyanin-type proteins displaying apparent sequence similarities.
Functional domains are identified, and a comparison of predicted
hydrophilicities, surface probabilities, and regional backbone
flexibilities provides evidence for a remarkable degree of structural
conservation among the proteins surveyed. Parsimony analysis of the protein
sequence alignment identifies four monophyletic groups on the arthropodan
branch of the hemocyanin gene tree: crustacean hemocyanins, insect
hexamerins, chelicerate hemocyanins, and arthropodan prophenoloxidases.
They form a monophyletic group relative to molluscan hemocyanins and
nonarthropodan tyrosinases. Arthropodan prophenoloxidases, although
functionally similar to tyrosinases, appear to belong to the arthropodan
hexamer- type hemolymph proteins as opposed to molluscan hemocyanins and
tyrosinases.
相似文献
6.
Feiye Guo Ying Ding Nora Caberoy Gabriela Alvarado Feng Wang Rui Chen Wei Li 《Molecular biology of the cell》2015,26(12):2311-2320
Phagocytosis of shed photoreceptor outer segments (POSs) by retinal pigment epithelial (RPE) cells is critical to retinal homeostasis and shares many conserved signaling pathways with other phagocytes, including extrinsic regulations. Phagocytotic ligands are the key to cargo recognition, engulfment initiation, and activity regulation. In this study, we identified intracellular protein ATP-binding cassette subfamily F member 1 (ABCF1) as a novel RPE phagocytotic ligand by a new approach of functional screening. ABCF1 was independently verified to extrinsically promote phagocytosis of shed POSs by D407 RPE cells. This finding was further corroborated with primary RPE cells and RPE explants. Internalized POS vesicles were colocalized with a phagosome marker, suggesting that ABCF1-mediated engulfment is through a phagocytic pathway. ABCF1 was released from apoptotic cells and selectively bound to shed POS vesicles and apoptotic cells, possibly via externalized phosphatidylserine. ABCF1 is predominantly expressed in POSs and colocalized with the POS marker rhodopsin, providing geographical convenience for regulation of RPE phagocytosis. Collectively these results suggest that ABCF1 is released from and binds to shed POSs in an autocrine manner to facilitate RPE phagocytosis through a conserved pathway. Furthermore, the new approach is broadly applicable to many other phagocytes and will enable systematic elucidation of their ligands to understand extrinsic regulation and cargo recognition. 相似文献
7.
Phagocytosis is an important process for the removal of apoptotic cells or cellular debris. Eat-me signals control the initiation of phagocytosis and hold the key for in-depth understanding of its molecular mechanisms. However, because of difficulties to identify unknown eat-me signals, only a limited number of them have been identified and characterized. Using a newly developed functional cloning strategy of open reading frame (ORF) phage display, we identified nine putative eat-me signals, including tubby-like protein 1 (Tulp1). This further led to the elucidation of tubby as the second eat-me signal in the same protein family. Both proteins stimulated phagocytosis of retinal pigment epithelium (RPE) cells and macrophages. Tubby-conjugated fluorescent microbeads facilitated RPE phagocytosis. Tubby and Tulp1, but not other family members, enhanced the uptake of membrane vesicles by RPE cells in synergy. Retinal membrane vesicles of Tubby mice and Tulp1−/− mice showed reduced activities for RPE phagocytosis, which were compensated by purified tubby and Tulp1, respectively. These data reveal a novel activity of tubby and Tulp1, and demonstrate that unbiased identification of eat-me signals by the broadly applicable strategy of ORF phage display can provide detailed insights into phagocyte biology. 相似文献
8.
Phage display with antibody libraries has been widely used with versatile applications. However, phage display with cDNA libraries
is rare and inefficient. Because of uncontrollable reading frames and stop codons in cDNA repertoires, high percentage of
phage clones identified from conventional cDNA libraries are non-open reading frames (non-ORFs) encoding unnatural short peptides
with minimal implications in protein networks. Consequently, phage display has not been used as a technology of functional
proteomics to elucidate protein–protein interactions like yeast two-hybrid system and mass spectrometry-based technologies.
Several strategies, including C-terminal display and ORF cDNA libraries, have been explored to circumvent the technical problem.
The accumulative endeavors eventually led to the efficient elucidation of a large number of tubby- and phosphatidylserine-binding
proteins in recent studies by ORF phage display with minimal reading frame issue. ORF phage display inherits all the versatile
applications of antibody phage display, but enables efficient identification of real endogenous proteins with efficiency,
sensitivity, and accuracy comparable to other technologies of functional proteomics. Its ELISA-like procedure can be conveniently
adapted by individual laboratories or fully automated for high-throughput screening. Thus, ORF phage display is an efficient,
sensitive, versatile, and convenient technology of functional proteomics for elucidation of global and pathway-specific protein–protein
interactions, disease mechanisms, or therapeutic targets. 相似文献
9.
Charlie T Cheng Enrique M Ostrea Jr Joseph NB Alviedo Felix P Banadera Ronald L Thomas 《Experimental biology and medicine (Maywood, N.J.)》2021,246(4):380
To determine if meconium fatty acid ethyl esters (FAEE) in rat pups is a good biomarker of prenatal exposure and effect to alcohol, three groups of pregnant rats were studied: one control (pair fed) and two treatment groups given 25% alcohol at 2.2 or 5.5 g−1 kg−1 d−1. The pups were delivered on day 20 and, for each dam, were separated into a male and female group. The body, brain, intestines, and placenta of the pups were obtained, weighed, and stored at −20°C. The pups’ intestines (as surrogate of meconium) from each group were pooled, and meconium was analyzed by gas chromatography/mass spectroscopy for FAEE. The meconium showed the following FAEE: ethyl palmitate, ethyl stearate, and ethyl linolenate and were only found in the alcohol-treated group and with high specificity but low sensitivity. Mean body weight of the pups was lower in the treatment groups compared to the control groups. Ethyl palmitate concentration correlated negatively to the pups’ mean body and brain weights. Therefore, ethyl palmitate, stearate, and linolenate, in meconium of rat pups prenatally exposed to alcohol, are useful biomarkers of prenatal alcohol exposure, with ethyl palmitate a good biomarker of adverse effect on the pups’ body and brain weight. 相似文献
10.
Ying Ding Nora B. Caberoy Feiye Guo Michelle E. LeBlanc Chenming Zhang Weiwen Wang Feng Wang Rui Chen Wei Li 《PloS one》2015,10(5)
Phagocytosis is critical to the clearance of apoptotic cells, cellular debris and deleterious metabolic products for tissue homeostasis. Phagocytosis ligands directly recognizing deleterious cargos are the key to defining the functional roles of phagocytes, but are traditionally identified on a case-by-case basis with technical challenges. As a result, extrinsic regulation of phagocytosis is poorly defined. Here we demonstrate that microglial phagocytosis ligands can be systematically identified by a new approach of functional screening. One of the identified ligands is reticulocalbin-1 (Rcn1), which was originally reported as a Ca2+-binding protein with a strict expression in the endoplasmic reticulum. Our results showed that Rcn1 can be secreted from healthy cells and that secreted Rcn1 selectively bound to the surface of apoptotic neurons, but not healthy neurons. Independent characterization revealed that Rcn1 stimulated microglial phagocytosis of apoptotic but not healthy neurons. Ingested apoptotic cells were targeted to phagosomes and co-localized with phagosome marker Rab7. These data suggest that Rcn1 is a genuine phagocytosis ligand. The new approach described in this study will enable systematic identification of microglial phagocytosis ligands with broad applicability to many other phagocytes. 相似文献