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751.
Fernández MR Porté S Crosas E Barberà N Farrés J Biosca JA Parés X 《Cellular and molecular life sciences : CMLS》2007,64(11):1419-1427
ζ-crystallins constitute a family of proteins with NADPH:quinone reductase activity found initially in mammalian lenses but
now known to be present in many other organisms and tissues. Few proteins from this family have been characterized, and their
function remains unclear. In the present work, ζ-crystallins from human and yeast (Zta1p) were expressed, purified and characterized.
Both enzymes are able to reduce ortho-quinones in the presence of NADPH but are not active with 2-alkenals. Deletion of the ZTA1 gene makes yeast more sensitive to menadione and hydrogen peroxide, suggesting a role in the oxidative stress response. The
human and yeast enzymes specifically bind to adenine-uracil rich elements (ARE) in RNA, indicating that both enzymes are ARE-binding
proteins and that this property has been conserved in ζ-crystallins throughout evolution. This supports a role for ζ-crystallins
as trans-acting factors that could regulate the turnover of certain mRNAs.
Received 21 February 2007; received after revision 16 April 2007; accepted 23 April 2007
M. R. Fernández, S. Porté: These authors contributed equally to this work. 相似文献
752.
Zhang X Beaulieu JM Gainetdinov RR Caron MG 《Cellular and molecular life sciences : CMLS》2006,63(1):6-11
Many neuropsychiatric disorders are considered to be related to the dysregulation of brain serotonergic neurotransmission.
Tryptophan hydroxylase-2 (TPH2) is the neuronal-specific enzyme that controls brain serotonin synthesis. There is growing
genetic evidence for the possible involvement of TPH2 in serotonin-related neuropsychiatric disorders; however, the degree of genetic variation in TPH2 and, in particular, its possible functional consequences remain unknown. In this short review, we will summarize some recent
findings with respect to the functional analysis of TPH2.
Received 12 September 2005; received after revision 25 October 2005; accepted 31 October 2005 相似文献
753.
Dynamics of estrogen binding by uterine cells in vivo 总被引:1,自引:0,他引:1
The dynamics of the in vivo binding and release of tritiated estradiol in different uterine cell types are described. The very early binding of estrogens by the cytosol-nuclear and the eosinophil receptor systems is in accordance with the hypothesis that some estrogenic effects are mediated by these receptor systems. 相似文献
754.
Yuan J Dong Z Guo JP McGeehan J Xiao X Wang J Cali I McGeer PL Cashman NR Bessen R Surewicz WK Kneale G Petersen RB Gambetti P Zou WQ 《Cellular and molecular life sciences : CMLS》2008,65(4):631-643
Human prion diseases are characterized by the accumulation in the brain of proteinase K (PK)-resistant prion protein designated
PrP27 – 30 detectable by the 3F4 antibody against human PrP109 – 112. We recently identified a new PK-resistant PrP species,
designated PrP*20, in uninfected human and animal brains. It was preferentially detected with the 1E4 antibody against human PrP 97 – 108 but
not with the anti-PrP 3F4 antibody, although the 3F4 epitope is adjacent to the 1E4 epitope in the PrP*20 molecule. The present study reveals that removal of the N-terminal amino acids up to residue 91 significantly increases accessibility
of the 1E4 antibody to PrP of brains and cultured cells. In contrast to cells expressing wild-type PrP, cells expressing pathogenic
mutant PrP accumulate not only PrP*20 but also a small amount of 3F4-detected PK-resistant PrP27 – 30. Remarkably, during the course of human prion disease, a
transition from an increase in 1E4-detected PrP*20 to the occurrence of the 3F4-detected PrP27 – 30 was observed. Our study suggests that an increase in the level of PrP*20 characterizes the early stages of prion diseases.
Received 17 October 2007; received after revision 5 December 2007; accepted 14 December 2007 相似文献
755.
756.
Here we examine differentiation of the intestinal cell line Caco-2 following exposure to sodium butyrate (NaBT), using alkaline phosphatase (ALP) activity and carcinoembryonic antigen (CEA) levels as markers of differentiation. We show that acetylcholinesterase (AChE) activity and RNA levels increase during differentiation. Treatment with AChE inhibitors or knockdown of AChE levels by shRNA markedly decrease ALP and CEA levels in a concentration- and time-dependent manner. Finally, our observations suggest that NaBT-induced differentiation of intestinal cells involves AChE-induced cell cycle arrest. 相似文献
757.
Tang J Wu YM Zhao P Yang XM Jiang JL Chen ZN 《Cellular and molecular life sciences : CMLS》2008,65(18):2933-2942
Mechanism of HAb18G/CD147 underlying the metastasis process of human hepatoma cells has not been determined. In the present
study, we found that integrin α3β1 colocalizes with HAb18G/CD147 in human 7721 hepatoma cells. The enhancing effect of HAb18G/CD147
on adhesion, invasion capacities and matrix metalloproteinases (MMPs) secretion was decreased by integrin α3β1 antibodies
(p<0.01). The expressions of integrin downstream molecules including focal adhesion kinase (FAK), phospho-FAK (p-FAK), paxillin,
and phospho-paxillin (p-paxillin) were increased in human hepatoma cells overexpressing HAb18G/CD147. Deletion of HAb18G/CD147
reduces the quantity of focal adhesions and rearranges cytoskeleton. Wortmannin and LY294002, specific phosphatidylinositol
kinase (PI3K) inhibitors, reversed the effect of HAb18G/CD147 on the regulation of intracellular Ca2+ mobilization, significantly reducing cell adhesion, invasion and MMPs secretion potential (p<0.01). Together, these results suggest that HAb18G/CD147 enhances the invasion and metastatic potentials of human hepatoma
cells via integrin α3β1-mediated FAK-paxillin and FAKPI3K-Ca2+ signal pathways.
Received 5 June 2008; received after revision 16 July 2008; accepted 23 July 2008 相似文献
758.
Ma Y Cai S Lu Q Lu X Jiang Q Zhou J Zhang C 《Cellular and molecular life sciences : CMLS》2008,65(19):3100-3109
Inhibition of protein deacetylation arrests cells in mitosis, but the mechanism is unknown. To understand why inhibiting protein
deacetylation causes cell cycle arrest, we treated HeLa cells beyond G1/S transition with trichostatin A (TSA), a potent protein
deacetylase inhibitor, and found that the cells arrested at prometaphase with ectopic spindles and unaligned chromosomes.
The hyper-acetylated cells encountered a serious microtubule (MT)-kinetochore attachment problem, although the kinetochores
are intact at ultrastructural level. By immunofluorescence staining of kinetochore proteins, we found that the pericentromeric
H3K9Me3-HP1 pathway was disrupted and that the CENP-A-dependent outer plate protein dynamics of kinetochores was greatly diminished
by the drug treatment. The treatment also caused the loss of chromosome passenger complex (CPC), the proposed error checking
system, from centromere and impaired the microtubule dynamics of the cells. Overall, we propose that deacetylation inhibition
impairs MT-kinetochore attachment through disrupting the centromere function and altering the kinetochore composition and
MT dynamics.
Received 30 April 2008; received after revision 28 July 2008; accepted 14 August 2008 相似文献
759.
REGγ, a proteasome activator and beyond? 总被引:1,自引:0,他引:1
REGγ, a member of the 11S proteasome activators, has been shown to bind and activate the 20S proteasome to promote proteasome-dependent
degradation of important regulatory proteins, such as SRC-3 and cyclin-dependent kinase inhibitors p21, p16, and p19, in a
ubiquitin- and ATP-independent manner. Furthermore, REGγ has been shown to facilitate the turnover of tumor suppressor p53
by promoting MDM2-mediated p53 ubiquitination. The discovery that REGγ regulates cell-cycle regulators is consistent with
previous studies where REGγ-deficient mice have shown retardation in body growth, decreased cell proliferation and increased
apoptosis, indicating a potential role of REGγ in cancer development. Additionally, REGγ’s ability to promote viral protein
degradation suggests its involvement in viral pathogenesis. This review presents an overview of the function of REGγ, a summary
of the current literature, and insight into the possible biological function of REGγ relating to cancer, viral pathogenesis,
and other diseases. 相似文献