共查询到20条相似文献,搜索用时 15 毫秒
1.
Ion channels in plant signaling 总被引:5,自引:0,他引:5
S. Zimmermann T. Ehrhardt G. Plesch B. Müller-Röber 《Cellular and molecular life sciences : CMLS》1999,55(2):183-203
Plant ion channel activities are rapidly modulated in response to several environmental and endogenous stimuli such as light,
pathogen attack and phytohormones. Electrophysiological as well as pharmacological studies provide strong evidence that ion
channels are essential for the induction of specific cellular responses, implicating their tight linkage to signal transduction
cascades. Ion channels propagate signals by modulating the membrane potential or by directly affecting cellular ion composition.
In addition, they may also be effectors at the end of signaling cascades, as examplified by ion channels which determine the
solute content of stomatal guard cells. Plant channels are themselves subject to regulation by a variety of cellular factors,
including calcium, pH and cyclic nucleotides. In addition, they appear to be regulated by (de)-phosphorylation events as well
as by direct interactions with cytoskeletal and other cellular proteins. This review summarizes current knowledge on the role
of ion chan nels in plant signaling. 相似文献
2.
Signalling roles of mammalian phospholipase D1 and D2 总被引:11,自引:0,他引:11
S. Cockcroft 《Cellular and molecular life sciences : CMLS》2001,58(11):1674-1687
Phospholipase D (PLD) catalyses the hydrolysis of phosphatidylcholine to generate the lipid second messenger, phosphatidate
(PA) and choline. PLD activity in mammalian cells is low and is transiently stimulated upon activation by G-protein-coupled
and receptor tyrosine kinase cell surface receptors. Two mammalian PLD enzymes (PLD1 and PLD2) have been cloned and their
intracellular regulators identified as ARF and Rho proteins, protein kinase Cα as well as the lipid, phosphatidylinositol
[4, 5] bisphosphate (PIP2). I discuss the regulation of these enzymes by cell surface receptors, their cellular localisation and the potential function
of PA as a second messenger. Evidence is presented for a role of PA in regulating the lipid kinase activity of PIP 5-kinase,
an enzyme that synthesises PIP2. A signalling role of phospholipase D via PA and indirectly via PIP2 in regulating membrane traffic and actin dynamics is indicated by the available data.
Received 25 April 2001; received after revision 15 June 2001; accepted 15 June 2001 相似文献
3.
Novel regulation and function of Src tyrosine kinase 总被引:4,自引:0,他引:4
Src tyrosine kinase is a critical signal transducer that modulates a wide variety of cellular functions. Misregulation of
Src leads to cell transformation and cancer. Heterotrimeric guanine-nucleotide-binding proteins (G proteins) are another group
of signaling molecules that transduce signals from cell-surface receptors to generate physiological responses. Recently, it
was discovered that Gαs and Gαi could directly stimulate Src family tyrosine kinase activity. This novel regulation of Src
tyrosine kinase by G proteins provides insights into the adenylyl cyclase-independent signaling mechanisms involved in ligand-induced
receptor desensitization, internalization and other physiological processes.
Received 17 August 2001; received after revision 22 October 2001; accepted 24 October 2001 相似文献
4.
P. C. Newell D. Malchow J. D. Gross 《Cellular and molecular life sciences : CMLS》1995,51(12):1155-1165
Changes in cytosolic Ca2+ play an important role in a wide array of cell types and the control of its concentration depends upon the interplay of many cellular constituents. Resting cells maintain cytosolic calcium ([Ca2+]i) at a low level in the face of steep gradients of extracellular and sequestered Ca2+. Many different signals can provoke the opening of calcium channels in the plasma membrane or in intracellular compartments and cause rapid influx of Ca2+ into the cytosol and elevation of [Ca2+]i. After such stimulation Ca2+ ATPases located in the plasma membrane and in the membranes of intracellular stores rapidly return [Ca2+]i to its basal level. Such responses to elevation of [Ca2+]i are a part of an important signal transduction mechanism that uses calcium (often via the binding protein calmodulin) to mediate a variety of cellular actions responsive to outside influences. 相似文献
5.
Daniela Corda Pasquale Zizza Alessia Varone Beatrice Maria Filippi Stefania Mariggiò 《Cellular and molecular life sciences : CMLS》2009,66(21):3449-3467
The glycerophosphoinositols are cellular products of phospholipase A2 and lysolipase activities on the membrane phosphoinositides. Their intracellular concentrations can vary upon oncogenic transformation,
cell differentiation and hormonal stimulation. Specific glycerophosphodiester phosphodiesterases are involved in their catabolism,
which, as with their formation, is under hormonal regulation. With their mechanisms of action including modulation of adenylyl
cyclase, intracellular calcium levels, and Rho-GTPases, the glycerophosphoinositols have diverse effects in multiple cell
types: induction of cell proliferation in thyroid cells; modulation of actin cytoskeleton organisation in fibroblasts; and
reduction of the invasive potential of tumour cell lines. More recent investigations include their effects in inflammatory
and immune responses. Indeed, the glycerophosphoinositols enhance cytokine-dependent chemotaxis in T-lymphocytes induced by
SDF-1α-receptor activation, indicating roles for these compounds as modulators of T-cell signalling and T-cell responses. 相似文献
6.
Pacheco YM Abia R Olivera A Spiegel S Ruiz-Gutierrez V Muriana FJ 《Cellular and molecular life sciences : CMLS》2003,60(12):2757-2766
Proof for the role of triacylglycerol-rich lipoproteins (TRLs) in the development of cardiovascular events is accumulating. We recently reported that postprandial TRLs bind to and internalize into human aortic vascular smooth muscle cells (HA-VSMCs) by a lipid-dependent mechanism. We now show that postprandial TRLs triggered hydrolysis of sphingomyelin and stimulation of the sphingosine kinase producing sphingosine 1-phosphate (S1P). In addition, postprandial TRLs exhibited survival and mitogenic effects. Interestingly, the signals were modulated by the nature of the fatty acids located at the sn-2 position in the triacylglycerol molecules of TRL. This lipid-stereospecific regulation of S1P cellular levels in HA-VSMCs provides a novel insight into the intrinsic role of dietary fatty acids and the mechanism mediated by triacylglycerol-containing postprandial lipoproteins in the pathogenesis of atherosclerosis.Received 14 August 2003; received after revision 8 October 2003; accepted 15 October 2003 相似文献
7.
The p53 protein was discovered 20 years ago, as a cellular protein tightly bound to the large T oncoprotein of the SV40 DNA
tumour virus. Since then, research on p53 has developed in many exciting and sometimes unexpected directions. p53 is now known
to be the product of a major tumour suppressor gene that is the most common target for genetic alterations in human cancer.
The nonmutated wild-type p53 protein (wtp53) is often found within cells in a latent state and is activated in response to
various intracellular and extracellular signals. Activation involves an increase in overall p53 protein levels, as well as
qualitative changes in the protein. Upon activation, wtp53 can induce a variety of cellular responses, most notable among
which are cell cycle arrest and apoptosis. To a great extent, these effects are mediated by the ability of p53 to activate
specific target genes. In addition, the p53 protein itself possesses biochemical functions which may facilitate DNA repair
as well as apoptosis. The role of p53 in normal development and particularly in carcinogenesis has been elucidated in depth
through the use of mouse model systems. The insights provided by p53 research over the years are now beginning to be utilized
towards better diagnosis, prognosis and treatment of cancer. 相似文献
8.
Signalling in viral entry 总被引:9,自引:0,他引:9
Greber UF 《Cellular and molecular life sciences : CMLS》2002,59(4):608-626
Viral infections are serious battles between pathogens and hosts. They can result in cell death, elimination of the virus
or latent infection keeping both cells and pathogens alive. The outcome of an infection is often determined by cell signalling.
Viruses deliver genomes and proteins with signalling potential into target cells and thereby alter the metabolism of the host.
Virus interactions with cell surface receptors can elicit two types of signals, conformational changes of viral particles,
and intracellular signals triggering specific cellular reactions. Responses by cells include stimulation of innate and adaptive
immunity, growth, proliferation, survival and apoptosis. In addition, virus-activated cell signalling boosts viral entry and
gene delivery, as recently shown for adenoviruses and adeno-associated viruses. This review illustrates that multiple activation
of host cells during viral entry profoundly impacts the elaborate relationship between hosts and viral pathogens.
Received 13 September 2001; received after revision 23 October 2001; accepted 16 November 2001 相似文献
9.
Mitchell Y. Sun Melissa Geyer Yulia A. Komarova 《Cellular and molecular life sciences : CMLS》2017,74(22):4189-4207
The endothelium, a monolayer of endothelial cells lining vessel walls, maintains tissue-fluid homeostasis by restricting the passage of the plasma proteins and blood cells into the interstitium. The ion Ca2+, a ubiquitous secondary messenger, initiates signal transduction events in endothelial cells that is critical to control of vascular tone and endothelial permeability. The ion Ca2+ is stored inside the intracellular organelles and released into the cytosol in response to environmental cues. The inositol 1,4,5-trisphosphate (IP3) messenger facilitates Ca2+ release through IP3 receptors which are Ca2+-selective intracellular channels located within the membrane of the endoplasmic reticulum. Binding of IP3 to the IP3Rs initiates assembly of IP3R clusters, a key event responsible for amplification of Ca2+ signals in endothelial cells. This review discusses emerging concepts related to architecture and dynamics of IP3R clusters, and their specific role in propagation of Ca2+ signals in endothelial cells. 相似文献
10.
Rosenstiel P Jacobs G Till A Schreiber S 《Cellular and molecular life sciences : CMLS》2008,65(9):1361-1377
NOD-like receptors (NLRs) comprise a family of cytosolic proteins that have been implicated as ancient cellular sentinels
mediating protective immune responses elicited by intracellular pathogens or endogenous danger signals. Genetic variants in
NLR genes have been associated with complex chronic inflammatory barrier diseases (e.g. Crohn disease, bronchial asthma). In
this review, we focus on the molecular pathophysiology of NLRs in the context of chronic inflammatory diseases and pinpoint
recent advances in the evolutionary understanding of NLR biology. We propose that the field of NLRs may serve as a prototype
for how a comprehensive understanding of an element of the immunological barrier will eventually lead to the development of
targeted diagnostic, therapeutic and/or preventive strategies.
Received 29 October 2007; received after revision 10 December 2007; accepted 19 December 2007 相似文献
11.
The novel polyamine derivatives sulphonamido oxa-spermine (oxa-Spm) and sulphonamido oxa-spermidine (oxa-Spd) exhibited rapid
cytotoxic action towards MCF-7 human breast cancer cells with IC50 values of 4.35 and 6.47 μM, respectively, after 24-h drug exposure. Neither compound is a substrate of serum amine oxidase.
Both oxa-Spm and oxa-Spd caused cell shrinkage, as determined by phase-contrast microscopy. After incubation with 10 μM of
either compound for 8 h, the cells underwent chromatin condensation and nuclear fragmentation. However, no clear DNA ladder
was obtained by electrophoresis. The sulphonamido oxa-polyamine derivatives and especially oxa-Spd enhanced the activity of
polyamine oxidase (PAO), an enzyme capable of oxidising N1-acetylated spermine and spermidine to spermidine and putrescine, respectively, generating cytotoxic H2O2 and 3-acetamidopropanal as by-products. The intracellular polyamine content was only marginally reduced in response to drug
treatment. In conclusion, our data show that these novel sulphonamido oxa-polyamine derivatives possess high cytotoxic activity
against MCF-7 cells and indicate that induction of PAO may mediate their cytotoxicity via apoptosis.
Received 17 January 2002; received after revision 22 February 2002; accepted 22 February 2002 相似文献
12.
V. J. Csernus T. Hammer D. Peschke E. Peschke 《Cellular and molecular life sciences : CMLS》1998,54(7):733-743
Insulin secretion from isolated pancreatic islets of 8- to 12-day-old rats was investigated in a dynamic in vitro (perifusion)
system. The aims of the study were (i) to describe a carefully controlled in vitro method to study the mechanism of insulin
secretion and to analyse the effects and dynamic interactions of bioactive compounds on isolated rat pancreatic islets, (ii)
to validate the method by comparing fundamental data on the functions of the islets obtained with this method to those collected
with other techniques; and (iii) to find novel features of the control of insulin secretion. The method was carefully designed
to maintain the functional capacity of the explanted cells. A functional standardization system was elaborated consisting
of (i) analysis of the changes in the basal hormone secretion of the cells; (ii) evaluating responses to a standard, specific
stimuli (50 mM glucose for 3 min); (iii) determining the alteration of the momentary size of the hormone pool with responses
to KCl; and (iv) direct determination of the total intracellular hormone content from the extract of the column. The technique
provides accurate quantitative data on the dynamic responses to biologically active compounds that act directly on the pancreatic
islets. The islets maintained their full responsiveness for up to 7 days, and responses as close as in 1-min intervals could
be distinguished. A linear dose-response relationship was found on the glucose-induced insulin release in case of 3-min stimulation
with 4 and 500 mM of glucose (lin-log graph). Utilizing this method, we showed that no desensitization to glucose-induced
insulin release can be observed if the responsiveness of the cells is properly maintained and the parameters of the stimulation
are carefully designed. Exposure of the explanted islets to 10 μM acetylcholine or 30 mM arginine (Arg) induced a transitory
elevation of insulin release similar in shape to that experienced after glucose stimulation. Norepinephrine (NE), dopamine
(DA) and somatostatin (SS) did not induce any detectable alteration on the basal insulin secretion of the islets. However,
100 nM SS given together with 50 mM glucose, 30 mM Arg or 10 μM acetylcholine significantly reduced the insulin-releasing
effect of these substances (by 75.5, 71.5 and 72.5%, respectively). At the same time, SS did not alter the insulin response
of the islets to 100 mM elevation of K+ concentration. SS also inhibited glucose-induced insulin release in a dose-dependent way (ED50 = 22 nM). A similar dose-dependent inhibitory effect on glucose-induced insulin release was found with NE (ED50 = 89 nM) and DA (ED50 = 2.2 μM). γ-Aminobutyric acid (GABA) did not influence insulin release under similar circumstances.
Received 16 January 1998; received after revision 6 May 1998; accepted 8 May 1998 相似文献
13.
Katja Gehrig-Burger Jirina Slaninova Gerald Gimpl 《Cellular and molecular life sciences : CMLS》2010,67(16):2815-2824
Progesterone non-genomically attenuates the calcium signaling of the human oxytocin receptor and several other Gαq protein-coupled receptors. High progesterone concentrations are found in the endometrium during pregnancy opposing the responsiveness
of the underlying myometrium to labor-inducing hormones. Here, we demonstrate that within minutes, progesterone inhibits oxytocin-
and bradykinin-induced contractions of rat uteri, calcium responses induced by platelet-activating factor in the human endometrial
cell line MFE-280, and oxytocin-induced calcium signals in PHM1-31 immortalized pregnant human myometrial cells. Using human
embryonic kidney (HEK293) cells as model system, we analyzed the molecular mechanisms underlying these effects. Our data indicate
that progesterone rapidly depletes intracellular calcium stores. The resulting desensitization of the cells might contribute
to the quiescence of the uterus during pregnancy. 相似文献
14.
Elizabeth Brint Grace O’Callaghan Aileen Houston 《Cellular and molecular life sciences : CMLS》2013,70(21):4085-4099
Fas, also known as CD95 or APO-1, is a member of the tumor necrosis factor/nerve growth factor superfamily. Although best characterized in terms of its apoptotic function, recent studies have identified several other cellular responses emanating from Fas. These responses include migration, invasion, inflammation, and proliferation. In this review, we focus on the diverse cellular outcomes of Fas signaling and the molecular switches identified to date that regulate its pro- and anti-apoptotic functions. Such switches occur at different levels of signal transduction, ranging from the receptor through to cross-talk with other signaling pathways. Factors identified to date including other extracellular signals, proteins recruited to the death-inducing signaling complex, and the availability of different intracellular components of signal transduction pathways. The success of therapeutically targeting Fas will require a better understanding of these pathways, as well as the regulatory mechanisms that determine cellular outcome following receptor activation. 相似文献
15.
Ras proteins in the control of the cell cycle and cell differentiation 总被引:12,自引:0,他引:12
The Ras family of small GTPases includes three closely related proteins: H-, K-, and N-Ras. Ras proteins are involved in
the transduction of signals elicited by activated surface receptors, acting as key components by relaying signals downstream
through diverse pathways. Mutant, constitutively activated forms of Ras proteins are frequently found in cancer. While constitutive
Ras activation induces oncogenic-like transformation in immortalized fibroblasts, it causes growth arrest in primary vertebrate
cells. Induction of p53 and cyclin-dependent kinase inhibitors such as p15INK4b, p16INK4a, p19ARF, and p21WAF1 accounts for this response. Interestingly, while ras has usually been regarded as a transforming oncogene, the analysis of Ras function in most of the cellular systems studied
so far indicates that the promotion of differentiation is the most prominent effect of Ras. While in some cell types, particularly
muscle, Ras inhibits differentiation, in others such as neuronal, adipocytic, or myeloid cells, Ras induces differentiation,
in some cases accompanied by growth arrest. Several possible mechanisms for the pleiotropic effects of Ras in animal cells
are discussed.
Received 8 March 2000; received after revision 24 May 2000; accepted 24 May 2000 相似文献
16.
Decoding the Hedgehog signal in animal development 总被引:4,自引:0,他引:4
The Hedgehog (Hh) family of secreted proteins plays essential roles in a myriad of developmental processes via a complex signaling
cascade conserved in species ranging from insects to mammals. In many developmental contexts, Hh acts as long-range morphogen
to control distinct cellular outcomes as a function of its concentration. Here we review the current understanding of the
Hh signaling mechanisms that govern the establishment of the Hh gradient and the transduction of the Hh signal with an emphasis
on the intracellular signaling cascade from the receptor to the nuclear effector. We discuss how graded Hh signals are transduced
to govern distinct developmental outcomes.
Received 28 October 2005; received after revision 6 February 2006; accepted 15 February 2006 相似文献
17.
Melatonin biosynthesis in the mammalian pineal gland 总被引:8,自引:0,他引:8
D. Sugden 《Cellular and molecular life sciences : CMLS》1989,45(10):922-932
Summary Rhythmic production of melatonin by the mammalian pineal occurs in response to noradrenergic stimulation which produces a cascade of biochemical events within the pinealocyte. In the rat, massive changes in NAT activity result from an increase in intracellular c-AMP levels produced by a synergistic interaction whereby an 1 activation amplifies -adrenergic stimulation. The intracellular events mediating this effect are described. A major aspect of the temporal control of melatonin production is the programmed down-regulation of responses to noradrenergic stimulation once the initial surge of c-AMP is produced. Noradrenergic activation of the gland also influences other enzymic functions, including tryptophan hydroxylase and HIOMT activities, and produces a dramatic increase in intracellular c-GMP levels. Other neurotransmitters and neuropeptides, e.g. VIP, may also influence pineal function and comparisons are, made between the rat, the subject of the bulk of experimental studies, and other species. 相似文献
18.
ROPs in the spotlight of plant signal transduction 总被引:7,自引:0,他引:7
Berken A 《Cellular and molecular life sciences : CMLS》2006,63(21):2446-2459
Small guanine nucleotide binding proteins of the Rho family called ROP play a crucial role as regulators of signal transduction
in plants. They participate in pathways that influence growth and development, and the adaptation of plants to various environmental
situations. As members of the Ras superfamily, ROPs function as molecular switches cycling between a GDP-bound ‘off’ and a
GTP-bound ‘on’ state in a strictly regulated manner. Latest research provided fascinating new insights into ROP regulation
by novel guanine nucleotide exchange factors, unconventional GTPase activating proteins, and guanine nucleotide dissociation
inhibitors, which apparently organize localized ROP activation. Important progress has also been made concerning signaling
components upstream and downstream of the ROP cycle involving receptor-like serine/threonine kinases and effectors that can
manipulate cytoskeletal dynamics, intracellular calcium levels, H2O2 production and further cellular targets. This review outlines the fast developing knowledge on ROP GTPases highlighting their
specific features, regulation and roles in a cellular signaling context.
Received 28 April 2006; received after revision 2 June 2006; accepted 29 June 2006 相似文献
19.
The intracellular signaling pathways mediating the nuclear exclusion of the androgen receptor (AR) by melatonin were evaluated
in PC3 cells stably transfected with the AR. The melatonin-induced nuclear exclusion of the AR by melatonin (100 nM, 3 h)
was blocked by LY 83583 (an inhibitor of guanylyl cyclases). 8-Bromo-cGMP (a cell-permeable cGMP analog), mimicked the effect
of melatonin, as did ionomycin (a calcium ionophore) and PMA [an activator of protein kinase C (PKC)], and their effects were
blocked by GF-109203X (a selective PKC inhibitor). BAPTA (an intracellular calcium chelator) blocked the effects of melatonin
and 8-bromo-cGMP but not of PMA. Inhibition or activation of the protein kinase A pathway did not affect basal or melatonin-mediated
AR localization. We conclude that the melatonin-mediated rise in cGMP elicits AR nuclear exclusion via a pathway involving
increased intracellular calcium and PKC activation. These results define a novel signaling pathway that regulates AR localization
and androgen responses in target cells.
Received 31 July 2001; received after revision 18 September 2001; accepted 30 October 2001 相似文献
20.
The regulatory function of SPARC in vascular biology 总被引:1,自引:1,他引:0
SPARC is a matricellular protein, able to modulate cell/ECM interactions and influence cell responses to growth factors, and
therefore is particularly attuned to contribute to physiological processes involving changes in ECM and cell mobilization.
Indeed, the list of biological processes affected by SPARC includes wound healing, tumor progression, bone formation, fibrosis,
and angiogenesis. The process of angiogenesis is complex and involves a number of cellular processes such as endothelial cell
proliferation, migration, ECM degradation, and synthesis, as well as pericyte recruitment to stabilize nascent vessels. In
this review, we will summarize current results that explore the function of SPARC in the regulation of angiogenic events with
a particular emphasis on the modulation of growth factor activity by SPARC in the context of blood vessel formation. The primary
function of SPARC in angiogenesis remains unclear, as SPARC activity in some circumstances promotes angiogenesis and in others
is more consistent with an anti-angiogenic activity. Undoubtedly, the mercurial nature of SPARC belies a redundancy of functional
proteins in angiogenesis as well as cell-type-specific activities that alter signal transduction events in response to unique
cellular milieus. Nonetheless, the investigation of cellular mechanisms that define functional activities of SPARC continue
to contribute novel and exciting paradigms to vascular biology. 相似文献