共查询到20条相似文献,搜索用时 15 毫秒
1.
Light perception in higher plants 总被引:4,自引:0,他引:4
Batschauer A 《Cellular and molecular life sciences : CMLS》1999,55(2):153-166
Photosynthetic plants depend on sunlight as their energy source. Thus, they need to detect the intensity, quality and direction
of this critical environmental factor and to respond properly by optimizing their growth and development. Perception of light
is accomplished by several photoreceptors including phytochromes, blue/ultraviolet (UV)-A and UV-B light photoreceptors. In
recent years, genetic, molecular genetic and cell biological approaches have significantly increased our knowledge about the
structure and function of the photoreceptors, and allowed the identification of several light signal transduction components.
Furthermore, this research led to fruitful interaction between different disciplines, such as molecular biology and ecology.
It is safe to assume that we can expect more milestones in this research field in the upcoming years. 相似文献
2.
L.-y. Yu-Lee G. Luo S. Moutoussamy J. Finidori 《Cellular and molecular life sciences : CMLS》1998,54(10):1067-1075
The peptide hormones, prolactin (PRL) and growth hormone (GH), are known to regulate numerous target tissues. Among such targets are cells of the immune system, including T cells, B cells, macrophages and natural killer cells. We have cloned a panel of PRL- and GH-inducible T cell genes for use in studies to understand how these hormones through the expression of these genes modulate the biology of immune function cells. This article focuses on the signalling pathways emanating from the PRL receptor (PRL-R) and GH receptor (GH-R), and the expression of PRL-inducible target genes. 相似文献
3.
The recent development of functional models to analyze the early steps of the hepatitis C virus (HCV) life cycle has highlighted
that HCV entry is a slow and complex multistep process involving the presence of several entry factors. Initial host cell
attachment may involve glycosaminoglycans and the low-density lipoprotein receptor, after which the particle appears to interact
sequentially with three entry factors: the scavenger receptor class B type I, the tetraspanin CD81 and the tight-junction
protein claudin-1. Several serum components may also modulate HCV entry, while the recently discovered CD81 partner EWI-2wint
can block the interaction of the viral particle with CD81, potentially preventing infection in the cell types in which it
is expressed. After binding to the host cell, the HCV particle is internalized by clathrin-mediated endocytosis, with fusion
likely occuring in early endosomes. This review summarizes our current knowledge on HCV entry.
Received 27 June 2007; received after revision 2 August 2007; accepted 29 August 2007 相似文献
4.
Negative regulators of cytokine signal transduction 总被引:20,自引:0,他引:20
D. J. Hilton 《Cellular and molecular life sciences : CMLS》1999,55(12):1568-1577
5.
Frings S 《Cellular and molecular life sciences : CMLS》2001,58(4):510-519
When odorants bind to the sensory cilia of olfactory sensory neurons, the cells respond with an electrical output signal,
typically a short train of action potentials. This review describes the present state of knowledge about the olfactory signal
transduction process. In the last decade, a set of transduction molecules has been identified which help to explain many aspects
of the sensory response. Odor-induced second-messenger production, activation of transduction channels, the central role of
the ciliary Ca2+ concentration, as well as mechanisms that mediate adaptation, are all qualitatively understood on the basis of a consistent
scheme for chemoelectrical transduction. This scheme, although necessarily incomplete, can serve as a working model for further
experimentation which may reveal kinetical aspects of signal transduction processes in olfactory sensory neurons. 相似文献
6.
Modification of ligand-gated receptor function at the postsynaptic domain is one of the most important mechanisms by which
the efficacy of synaptic transmission in the nervous system is regulated. Traditionally, these types of modifications have
been thought to be achieved mainly by altering the channel-gating properties or conductance of the receptors. However, recent
evidence suggests that AMPA (α-amino-3-hydroxyl-5-methyl-4-isoxayolepropionic acid)-type ligand-gated glutamate receptors are continuously recycling between
the plasma membrane and the intracellular compartments via vesicle-mediated plasma membrane insertion and clathrin-dependent
endocytosis. Regulation of either receptor insertion or endocytosis results in a rapid change in the number of these receptors
expressed on the plasma membrane surface and in the receptor-mediated responses, thereby playing an important role in mediating
certain forms of synaptic plasticity. Thus, controlling the number of postsynaptic receptors by regulating the intracellular
trafficking and plasma membrane expression of the postsynaptic receptors may be a common and important mechanism of synaptic
plasticity in the mammalian central nervous system. 相似文献
7.
T-cell signal transduction and the role of protein kinase C 总被引:3,自引:0,他引:3
The T lymphocyte has a vital part to play in maintaining the host response to bacterial and viral infection and also appears
to play a key pathological role in autoimmune diseases such as rheumatoid arthritis. In this review, we summarize the signalling
pathways which trigger antigen-driven T-cell proliferation and examine the evidence which suggests that protein kinase C (PKC)
is fundamental to this process. Finally, we discuss the therapeutic potential that PKC inhibitors may have in the treatment
of autoimmune disease.
Received 31 March 1998; received after revision 19 May 1998; accepted 19 May 1998 相似文献
8.
Gasperi V Fezza F Pasquariello N Bari M Oddi S Agrò AF Maccarrone M 《Cellular and molecular life sciences : CMLS》2007,64(2):219-229
The molecular basis for the control of energy balance by the endocannabinoid anandamide (AEA) is still unclear. Here, we show
that murine 3T3-L1 fibroblasts have the machinery to bind, synthesize and degrade AEA, and that their differentiation into
adipocytes increases by approximately twofold the binding efficiency of cannabinoid receptors (CBR), and by approximately
twofold and approximately threefold, respectively, the catalytic efficiency of the AEA transporter and AEA hydrolase. In contrast,
the activity of the AEA synthetase and the binding efficiency of vanilloid receptor were not affected by the differentiation
process. In addition, we demonstrate that AEA increases by approximately twofold insulin-stimulated glucose uptake in differentiated
adipocytes, according to a CB1R-dependent mechanism that involves nitric oxide synthase, but not lipoxygenase or cyclooxygenase.
We also show that AEA binding to peroxisome proliferator-activated receptor-γ, known to induce differentiation of 3T3-L1 fibroblasts
into adipocytes, is not involved in the stimulation of glucose uptake.
Received 11 October 2006; received after revision 9 November 2006; accepted 28 November 2006
V.Gasperi and F. Fezza equally contributed to the study. 相似文献
9.
Interferons as a paradigm for cytokine signal transduction 总被引:6,自引:0,他引:6
10.
Benton R 《Cellular and molecular life sciences : CMLS》2006,63(14):1579-1585
Olfaction, the sense of smell, depends on large, divergent families of odorant receptors that detect odour stimuli in the
nose and transform them into patterns of neuronal activity that are recognised in the brain. The olfactory circuits in mammals
and insects display striking similarities in their sensory physiology and neuroanatomy, which has suggested that odours are
perceived by a conserved mechanism. Here I review recent revelations of significant structural and functional differences
between the Drosophila and mammalian odorant receptor proteins and discuss the implications for our understanding of the evolutionary
and molecular biology of the insect odorant receptors.
Received 23 March 2006; accepted 28 April 2006 相似文献
11.
Sphingolipids in mammalian cell signalling 总被引:12,自引:0,他引:12
Sphingolipids and their metabolites, ceramide, sphingosine and sphingosine-1-phosphate, are involved in a variety of cellular
processes including differentiation, cellular senescence, apoptosis and proliferation. Ceramide is the main second messenger,
and is produced by sphingomyelinase-induced hydrolysis of sphingomyelin and by de novo synthesis. Many stimuli, e.g. growth
factors, cytokines, G protein-coupled receptor agonists and stress (UV irradiation) increase cellular ceramide levels. Sphingomyelin
in the plasma membrane is located primarily in the outer (extracellular) leaflet of the bilayer, whilst sphingomyelinases
are found at the inner (cytosolic) face and within lysosomes/endosomes. Such cellular compartmentalisation restricts the site
of ceramide production and subsequent interaction with target proteins. Glycosphingolipids and sphingomyelin together with
cholesterol are major components of specialised membrane microdomains known as lipid rafts, which are involved in receptor
aggregation and immune responses. Many signalling molecules, for example Src family tyrosine kinases and glycosylinositolphosphate-anchored
proteins, are associated with rafts, and disruption of these domains affects cellular responses such as apoptosis. Sphingosine
and sphingosine-1-phosphate derived from ceramide are also signalling molecules. In particular, sphingosine-1-phosphate is
involved in proliferation, differentiation and apoptosis. Sphingosine-1-phosphate can act both extracellularly through endothelial-differentiating
gene (EDG) family G protein-coupled receptors and intracellularly through direct interactions with target proteins. The importance
of sphingolipid signalling in cardiovascular development has been reinforced by recent reports implicating EDG receptors in
the regulation of embryonic cardiac and vascular morphogenesis.
Received 16 May 2001; received after revision 29 June 2001; accepted 3 July 2001 相似文献
12.
Polyisoprenyl phosphates: natural antiinflammatory lipid signals 总被引:1,自引:0,他引:1
Lipoxins (LX) and aspirin-triggered 15-epimer LX are leukocyte-derived eicosanoids generated during host defense that serve
as down-regulatory signals. The specific intracellular events that govern cellular responses to inhibitory extracellular signals
are of wide interest in order to understand pivotal intracellular events in diseases characterized by enhanced inflammatory
responses, such as asthma, rheumatoid arthritis and atherosclerosis. We recently uncovered a novel role for polyisoprenyl
phosphates, in particular presqualene diphosphate (PSDP), as natural down-regulatory signals in human neutrophils that directly
inhibit phospholipase D and superoxide anion generation. Activation of LXA4 receptors (ALXR) reverses proinflammatory receptor-initiated decrements in PSDP and inhibits cellular responses. These findings
represent evidence for a novel paradigm for lipid-protein interactions in the control of cellular responses, namely receptor-initiated
degradation of repressor lipids that is subject to regulation by aspirin treatment via the actions of aspirin-triggered 15-epimer
LX at the ALXR, and identify new templates for antiinflammatory drugs by design. 相似文献
13.
植物抗旱分子机理研究进展 总被引:5,自引:0,他引:5
干旱胁迫是影响植物生长发育的主要逆境因子之一,高等植物在长期进化过程中,逐渐演变产生了对干旱胁迫的防御机制,以最大限度减轻干旱胁迫造成的伤害。本文概述了植物耐旱生理及其分子机制。 相似文献
14.
Martínez Muñoz C Post JA Verkleij AJ Verrips CT Boonstra J 《Cellular and molecular life sciences : CMLS》2001,58(7):990-996
Activation of mitogen-activated protein (MAP) kinase is essential for cyclin D1 expression and provides a link between mitogenic
signalling and cell cycle progression. Hydrogen peroxide (H2 O2 ) activates MAP kinase; however, it is not known whether this leads to cyclin D expression. Sustained expression of cyclin
D1 and D2 was observed when Her14 fibroblasts were incu-bated with 3 mM or higher H2 O2 concentrations. Similar results were obtained when cells were incubated in the presence of serum (FCS). However, the sustained
expres-complex sion of cyclin D1 and D2 upon H2 O2 treatment was not due to the MAP kinase pathway, because MAP kinase kinase inhibitors did not inhibit cyclin D expression.
Furthermore, cyclin D1 and D2 levels remained constant even after addition of a protein synthesis inhibitor, indicating that
the effect of H2 O2 was not due to induction of protein synthesis. These results indicate that H2 O2 reversibly inhibits the ubiquitin-proteasome dependent degra-dation of cyclin D1 and D2, probably by transiently in-hibiting
ubiquitination and/or the proteasome.
Received 12 March 2001; received after revision 5 April 2001; accepted 9 April 2001 相似文献
15.
16.
The polycystins: a novel class of membrane-associated proteins involved in renal cystic disease 总被引:2,自引:0,他引:2
Sandford R Mulroy S Foggensteiner L 《Cellular and molecular life sciences : CMLS》1999,56(7-8):567-579
Polycystin-1, polycystin-2 and polycystin-L are the predicted protein products of the PKD1, PKD2 and PKDL genes, respectively.
Mutations in PKD1 and PKD2 are responsible for almost all cases of autosomal dominant polycystic kidney disease (ADPKD). This
condition is one of the commonest mendelian disorders of man with a prevalence of 1:800 and is responsible for nearly 10%
of cases of end-stage renal failure in adults. The cloning of PKD1 and PKD2 in recent years has provided the initial steps
in defining the mechanisms underlying renal cyst formation in this condition, with the aim of defining pharmacological and
genetic interventions that may ameliorate the diverse and often serious clinical manifestations of this disease. The PKD genes
share regions of sequence similarity, and all predict integral membrane proteins. Whilst the predicted protein domain structure
of polycystin-1 suggests it is involved in cell-cell or cell-matrix interactions, the similarity of polycystin-2 and polycystin-L
to the pore-forming domains of some cation channels suggests that they all form subunits of a large plasma membrane ion channel.
In the few years since the cloning of the PKD genes, a consensus that defines the range of mutations, expression pattern,
interactions and functional domains of these genes and their protein products is emerging. This review will therefore attempt
to summarise these data and provide an insight in to the key areas in which polycystin research is unravelling the mechanisms
involved in renal cyst formation.
Received 22 February 1999; received after revision 5 July 1999; accepted 6 July 1999 相似文献
17.
18.
Visual pigment: G-protein-coupled receptor for light signals 总被引:5,自引:0,他引:5
The visual pigment present in photoreceptor cells is a prototypical G-protein-coupled receptor (GPCR) that receives a light signal from the outer environment using a light-absorbing chromophore, 11-cis-retinal. Through cis-trans isomerization of the chromophore, light energy is transduced into chemical free energy, which is in turn utilized for conformational changes in the protein to activate the retinal G-protein. In combination with site-directed mutagenesis, various spectroscopic and biochemical studies identified functional residues responsible for chromophore binding, color regulation, intramolecular signal transduction and G-protein coupling. Extensive studies reveal that these residues are localized into specific domains of visual pigments, suggesting a highly manipulated molecular architecture in visual pigments. In addition to the recent findings on dysfunctional mutations in patients with retinitis pigmentosa or congenital night blindness, the mechanism of intramolecular signal transduction in visual pigments and their evolutionary relationship are discussed. Received 20 July 1998; received after revision 9 September 1998; accepted 23 September 1998 相似文献
19.
K. J. Clemetson 《Cellular and molecular life sciences : CMLS》1998,54(6):499-501
Integrins are a family of adhesive receptors consisting of α- and β-subunits which attach cells together via adhesive protein ligands or bind cells to extracellular matrix. They are found on virtually all cell types and link the external ligand to the cytoskeleton of the cell. Integrins also act as signal transducers both from the outside of the cell to the interior and also inside-out. Their main functions are in recognition and in tight but regulated binding. The series of reviews presented here cover both basic aspects of integrin function, including signal transduction, snake disintegrins and structure and function of I-domains in some integrin α-subunits, as well as the role of integrins in diseases, cancer, inflammation and cardiovascular diseases. The search for suitable inhibitors of integrins for treatment of these diseases and future prospects for their use are also discussed. 相似文献
20.
Recent advances in mammalian RNA editing 总被引:7,自引:0,他引:7
C. M. Niswender 《Cellular and molecular life sciences : CMLS》1998,54(9):946-964