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Wyszukujesz frazę "signal transduction" wg kryterium: Temat


Tytuł:
Involvement of nitric oxide in central histaminergic stimulation of the hypothalamic-pituitary-adrenal axis
Autorzy:
Bugajski, A.J.
Koprowska, B.
Thor, P.
Glod, R.
Bugajski, J.
Powiązania:
https://bibliotekanauki.pl/articles/69131.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Fizjologiczne
Tematy:
corticosterone secretion
histamine
amthamine
brain
nitric oxide
signal transduction
neuroendocrine regulation
central histaminergic stimulation
neurotransmitter
central nervous system
hypothalamic-pituitary-adrenal axis
Źródło:
Journal of Physiology and Pharmacology; 2000, 51, 4,2
0867-5910
Pojawia się w:
Journal of Physiology and Pharmacology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Particulate guanylyl cyclases: multiple mechanisms of activation.
Autorzy:
Kobiałka, Marcin
Gorczyca, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/1044281.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
signal transduction
calcium-binding proteins
guanylyl cyclases
cyclic nucleotides
Opis:
Cyclic GMP (cGMP), a key messenger in several signal transduction pathways, is synthesized from GTP by a family of enzymes termed guanylyl cyclases, which are found in two forms: cytosolic (soluble) and membrane-bound (particulate). The past decade has brought significant progress in understanding the molecular mechanisms that underlie the regulation of particulate guanylyl cyclases and new members of their family have been identified. It has become more evident that the basic mechanism of catalysis of guanylyl cyclases is analogous to that recognized in adenylyl cyclases. Here we review the known basic mechanisms that contribute to the regulation of particulate guanylyl cyclases.
Źródło:
Acta Biochimica Polonica; 2000, 47, 3; 517-528
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of aluminium on plant growth and metabolism.
Autorzy:
Mossor-Pietraszewska, Teresa
Powiązania:
https://bibliotekanauki.pl/articles/1044097.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
aluminium
signal transduction pathway
phytotoxicity
plant response
oxidative stress
Opis:
Aluminium toxicity is one of the major factors that limit plant growth and development in many acid soils. Root cells plasma membrane, particularly of the root apex, seems to be a major target of Al toxicity. However, strong interaction of Al3+, the main Al toxic form, with oxygen donor ligands (proteins, nucleic acids, polysaccharides) results in the inhibition of cell division, cell extension, and transport. Although the identification of Al tolerance genes is under way, the mechanism of their expression remains obscure.Soil chemical factors that limit root growth in acid soils, diminish crop production, include Al, Mn and various cations, and also deficiency or unavailability of Ca, Mg, P, Mo, and Si. These effects are further complicated by interactions of Al with other ions in different plant genotypes and under stress conditions (Foy, 1992). Cytotoxicity of Al has been well documented in plants (Delhaize & Ryan, 1995; Horst et al., 1999; Kollmeier et al., 2000; Marienfeld et al., 2000). It is generally known that plants grown in acid soils due to Al solubility at low pH have reduced root systems and exhibit a variety of nutrient-deficiency symptoms, with a consequent decrease in yield. In many countries with naturally acid soils, which constitute about 40% of world arable soil (LeNoble et al., 1996), Al toxicity is a major agricultural problem, and is intensively studied in plant systems.The effects of aluminium on plant growth, crop yield, uptake and nutrients distribution in vegetative and reproductive parts are still not fully understood. This review discusses recent information on aluminium toxicity with an emphasis on plant response to Al stress.
Źródło:
Acta Biochimica Polonica; 2001, 48, 3; 673-686
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lipids and signal transduction in the nucleus.
Autorzy:
Dygas, Anna
Barańska, Jolanta
Powiązania:
https://bibliotekanauki.pl/articles/1044152.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
signal transduction
nucleus
Opis:
During the last few years a growing amount of data has accumulated showing phospholipid participation in nuclear signal transduction. Very recent data strongly support the hypothesis that signal transduction in the nucleus is autonomic. Local production of inositol polyphosphates, beginning with the activation of phospholipase C is required for their specific function in the nucleus. Enzymes which modify polyphosphoinositols may control gene expression. Much less information is available about the role of other lipids in nuclear signal transduction. The aim of this minireview is to stress what is currently known about nuclear lipids with respect to nuclear signal transduction.
Źródło:
Acta Biochimica Polonica; 2001, 48, 2; 541-549
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Protein phosphatase 2A: Variety of forms and diversity of functions
Autorzy:
Lechward, Katarzyna
Awotunde, Olubunmi
Świątek, Wojciech
Muszyńska, Grażyna
Powiązania:
https://bibliotekanauki.pl/articles/1044037.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
protein phosphatase 2A
signal transduction
protein-protein interactions
reversible phosphorylation
cell cycle
carcinogenesis.
Opis:
Protein phosphatase 2A (PP2A) comprises a diverse family of phosphoserine-and phosphothreonine-specific phosphatases present in all eukaryotic cells. All forms of PP2A contain a catalytic subunit (PP2Ac) which forms a stable complex with the structural subunit PR65/A. The heterodimer PP2Ac-PR65/A associates with regulatory proteins, termed variable subunits, in order to form trimeric holoenzymes attributed with distinct substrate specificity and targeted to different subcellular compartments. PP2Ac activity can be modulated by reversible phosphorylation on Tyr307 and methylation on C-terminal Leu309. Studies on PP2A have shown that this enzyme may be implicated in the regulation of metabolism, transcription, RNA splicing, translation, differentiation, cell cycle, oncogenic transformation and signal transduction.
Źródło:
Acta Biochimica Polonica; 2001, 48, 4; 921-933
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Signal transmission via G protein-coupled receptors in the light of rhodopsin structure determination.
Autorzy:
Ciarkowski, Jerzy
Drabik, Piotr
Giełdoń, Artur
Kaźmierkiewicz, Rajmund
Ślusarz, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/1044085.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
signal transduction
neurohypophyseal receptors
molecular modeling
GPCRs
Opis:
G protein-coupled receptors (GPCRs) transducing diverse external signals to cells via activation of heterotrimeric GTP-binding (G) proteins, estimated to mediate actions of 60% of drugs, had been resistant to structure determination until summer 2000. The first atomic-resolution experimental structure of a GPCR, that of dark (inactive) rhodopsin, thus provides a trustworthy 3D prototype for antagonist-bound forms of this huge family of proteins. In this work, our former theoretical GPCR models are evaluated against the new experimental template. Subsequently, a working hypothesis regarding the signal transduction mechanism by GPCRs is presented.
Źródło:
Acta Biochimica Polonica; 2001, 48, 4; 1203-1207
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrolysis of cyclic GMP in rat peritoneal macrophages.
Autorzy:
Witwicka, Hanna
Kobiałka, Marcin
Gorczyca, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/1043691.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
signal transduction
phosphodiesterases
cyclic nucleotides
macrophages
Opis:
Intact rat peritoneal macrophages (rPM) treated with 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of phosphodiesterases (PDEs), accumulated more cGMP than untreated cells. A PDE activity toward [3H]cGMP was detected in the soluble and particulate fractions of rPM. The hydrolysis of cGMP was Ca2+/calmodulin-independent but increased in the presence of cGMP excess. Similar results were obtained when [3H]cAMP was used as a substrate. The hydrolytic activity towards both nucleotides was inhibited in the presence of IBMX. Therefore, the PDEs of families 2, 5, 10 and 11 are potential candidates for cGMP hydrolysis in the rPM. They may not only regulate the cGMP level in a feedback-controlled way but also link cGMP-dependent pathways with those regulated by cAMP.
Źródło:
Acta Biochimica Polonica; 2002, 49, 4; 891-897
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Steroid signal transduction activated at the cell membrane: from plants to animals.
Autorzy:
Marcinkowska, Ewa
Więdłocha, Antoni
Powiązania:
https://bibliotekanauki.pl/articles/1043743.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
signal transduction pathways
membrane receptors
nuclear receptors
transcription factors
translocation
steroid hormones
Opis:
Steroid hormones in plants and in animals are very important for physiological and developmental regulation. In animals steroid hormones are recognized by nuclear receptors, which transcriptionally regulate specific target genes following binding of the ligand. In addition, numerous rapid effects generated by steroids appear to be mediated by a mechanism not depending on the activation of nuclear receptors. Although the existence of separate membrane receptors was postulated many years ago and hundreds of reports supporting this hypothesis have been published, no animal membrane steroid receptor has been cloned to date. Meanwhile, a plant steroid receptor from Arabidopsis thaliana has been identified and cloned. It is a transmembrane protein which specifically recognizes plant steroids (brassinosteroids) at the cell surface and has a serine/threonine protein kinase activity. It seems that plants have no intracellular steroid receptors, since there are no genes homologous to the family of animal nuclear steroid receptors in the genome of A. thaliana. Since the reason of the rapid responses to steroid hormones in animal cells still remains obscure we show in this article two possible explanations of this phenomenon. Using 1,25-dihydroxyvitamin D3 as an example of animal steroid hormone, we review results of our and of other groups concordant with the hypothesis of membrane steroid receptors. We also review the results of experiments performed with ovarian hormones, that led their authors to the hypothesis explaining rapid steroid actions without distinct membrane steroid receptors. Finally, examples of polypeptide growth factor that similarly to steroids exhibit a dual mode of action, activating not only cell surface receptors, but also intracellular targets, are discussed.
Źródło:
Acta Biochimica Polonica; 2002, 49, 3; 735-745
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metabolism of cyclic GMP in peritoneal macrophages of rat and guinea pig.
Autorzy:
Kobiałka, Marcin
Witwicka, Hanna
Siednienko, Jakub
Gorczyca, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/1043463.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
guinea pig
rat
signal transduction
phosphodiesterases
guanylyl cyclases
protein kinases
cyclic nucleotides
macrophages
Opis:
The aim of our studies was to establish which enzymes constitute the "cGMP pathway" in rat and guinea pig peritoneal macrophages (PM). We found that in guinea pig PM synthesis of the nucleotide was significantly enhanced in response to activators of soluble guanylyl cyclase (sGC) and it was only slightly stimulated by specific activators of particulate guanylyl cyclases (pGC). In contrast, rat PM responded strongly to atrial natriuretic peptide (ANP), the activator of pGC type A. The rat cells synthesized about three-fold more cGMP than an equal number of the guinea pig cells. The activity of phosphodiesterases (PDE) hydrolyzing cGMP was apparently regulated by cGMP itself in PM of both species and again it was higher in the rat cells than in those isolated from guinea pig. However, guinea pig PM revealed an activity of Ca2+/calmodulin-dependent PDE1, which was absent in the rat cells. Using Western blotting analysis we were unable to detect the presence of cGMP-dependent protein kinase 1 (PKG1) in PM isolated from either species. In summary, our findings indicate that particulate GC-A is the main active form of GC in the rat PM, while in guinea pig macrophages the sGC activity dominates. Since the profiles of the PDE activities in rat and guinea pig PM are also different, we conclude that the mechanisms regulating cGMP metabolism in PM are species-specific. Moreover, our results suggest that targets for cGMP other than PKG1 should be present in PM of both species.
Źródło:
Acta Biochimica Polonica; 2003, 50, 3; 837-847
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Slowing down aging from within: mechanistic aspects of anti-aging hormetic effects of mild heat stress on human cells.
Autorzy:
Rattan, Suresh
Gonzalez-Dosal, Regina
Nielsen, Elise
Kraft, David
Weibel, Jens
Kahns, Søren
Powiązania:
https://bibliotekanauki.pl/articles/1043285.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
aging
signal transduction
anti-aging
longevity
proteasome
heat shock
Opis:
Since aging is primarily the result of a failure of maintenance and repair mechanisms, various approaches are being developed in order to stimulate these pathways and modulate the process of aging. One such approach, termed hormesis, involves challenging cells and organisms by mild stress that often results in anti-aging and life prolonging effects. In a series of experimental studies, we have reported that repeated mild heat stress (RMHS) has anti-aging hormetic effects on growth and various cellular and biochemical characteristics of human skin fibroblasts undergoing aging in vitro. These beneficial effects of repeated challenge include the maintenance of stress protein profile, reduction in the accumulation of oxidatively and glycoxidatively damaged proteins, stimulation of the proteasomal activities for the degradation of abnormal proteins, improved cellular resistance to other stresses, and enhanced levels of cellular antioxidant ability. In order to elucidate the molecular mechanisms of hormetic effects of RMHS, we are now undertaking studies on signal transduction pathways, energy production and utilisation kinetics, and the proteomic analysis of patterns of proteins synthesised and their posttranslational modifications in various types of human cells undergoing cellular aging in vitro. Human applications of hormesis include early intervention and modulation of the aging process to prevent or delay the onset of age-related conditions, such as sarcopenia, Alzheimer's disease, Parkinson's disease, cataracts and osteoporosis.
Źródło:
Acta Biochimica Polonica; 2004, 51, 2; 481-492
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
TGF beta signalling and its role in tumour pathogenesis.
Autorzy:
Kaminska, Bozena
Wesolowska, Aleksandra
Danilkiewicz, Malgorzata
Powiązania:
https://bibliotekanauki.pl/articles/1041410.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Smad propteins
RNA interference.
TGF beta signal transduction
tumour invasion
cancer therapy
MAP kinases
Opis:
Transforming growth factor beta (TGF-β) is a multifunctional cytokine involved in the regulation of cell proliferation, differentiation and survival/or apoptosis of many cells. Knock-out experiments in mice for the three isoforms of TGF-β have demonstrated their importance in regulating inflammation and tissue repair. TGF-β is implicated in the pathogenesis of human diseases, including tissue fibrosis and carcinogenesis. TGF-β receptors act through multiple intracellular pathways. Upon binding of TGF-β with its receptor, receptor-regulated Smad2/3 proteins become phosphorylated and associate with Smad4. Such complex translocates to the nucleus, binds to DNA and regulates transcription of specific genes. Negative regulation of TGF-β/Smad signalling may occur through the inhibitory Smad6/7. Furthermore, TGF-β-activated kinase-1 (TAK1) is a component of TGF-β signalling and activates stress-activated kinases: p38 through MKK6 or MKK3 and c-Jun N-terminal kinases (JNKs) via MKK4. In the brain TGF-β, normally expressed at the very low level, increases dramatically after injury. Increased mRNA levels of the three TGF-β isoforms correlate with the degree of malignancy of human gliomas. TGF-βs are secreted as latent precursors requiring activation into the mature form. TGF-β may contribute to tumour pathogenesis by direct support of tumour growth and influence on local microenvironment, resulting in immunosuppression, induction of angiogenesis, and modification of the extracellular matrix. TGF-β1,2 may stimulate production of vascular endothelial growth factor (VEGF) as well as plasminogen activator inhibitor (PAI-I), that are involved in vascular remodelling occurring during angiogenesis. Blocking of TGF-β action inhibits tumour viability, migration, metastases in mammary cancer, melanoma and prostate cancer model. Reduction of TGF-β production and activity may be a promising target of therapeutic strategies to control tumour growth.
Źródło:
Acta Biochimica Polonica; 2005, 52, 2; 329-337
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The basic biology of erbB-2 and its participation in colorectal cancers
Autorzy:
Stawińska, Magdalena
Bryś, Magdalena
Krajewska, Wanda M
Powiązania:
https://bibliotekanauki.pl/articles/764806.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
ErbB-2
colorectal cancers
signal transduction
tumour growth
Opis:
ErbB-2 is one of Tour cell surface growth factor receptors involved in transmission of signals controlling normal cell growth and differentiation. A range of growth factors serve as ligands, but none is specific for the ErbB-2 receptor. Ligand binding to ErbB-1, ErbB-3 and ErbB-4 induces rapid receptor dimerization, with a marked preference for ErbB-2 as a dimer partner. When ErbB-2 is overexpressed multiple ErbB-2 heterodimers are formed and cell signalling is stronger, resulting in enhanced responsiveness to growth factors and malignant growth. This explains why ErbB-2 overexpression is an indicator of poor prognosis in colorectal cancers and may be predictive of response to treatment. ErbB-2 is a highly specific and promising target for new colon cancer treatments.
Źródło:
Acta Universitatis Lodziensis. Folia Biologica et Oecologica; 2005, 2
1730-2366
2083-8484
Pojawia się w:
Acta Universitatis Lodziensis. Folia Biologica et Oecologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure and functions of plant calcium-dependent protein kinases
Autorzy:
Klimecka, Maria
Muszyńska, Grażyna
Powiązania:
https://bibliotekanauki.pl/articles/1041065.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
signal transduction
stress responses
cross-talk
calcium
plant protein kinases
Opis:
Calcium ions as second messengers play an essential role in many important cellular processes. In plants, transient changes in calcium content in the cytosol (calcium signatures) have been observed during growth, development and under stress conditions. Such diverse functions require many different calcium sensors. One of the largest and most differentiated group of calcium sensors are protein kinases, among them calcium-dependent protein kinases (CDPKs) which were identified only in plants and protists. CDPKs have a regulatory domain which is able to bind calcium ions. For regulation of CDPKs activities not only calcium ions but also specific phospholipids and autophosphorylation are responsible. CDPKs have many different substrates, which reflects the diversity of their functions. Potential protein substrates of CDPK are involved in carbon and nitrogen metabolism, phospholipid synthesis, defense responses, ion and water transport, cytoskeleton organization, transcription and hormone responses. Presently, participation of CDPKs in stress signal transduction pathways (e.g., cold, drought, high salinity, wounding) is intensively studied in many laboratories. An intriguing, but still not fully clarified problem is the cross-talk via CDPKs among different signaling pathways that enables signal integration at different levels and ensure appropriate downstream responses.
Źródło:
Acta Biochimica Polonica; 2007, 54, 2; 219-233
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Melatonina, wielofunkcyjna cząsteczka sygnałowa w organizmie ssaka: miejsca biosyntezy, funkcje, mechanizmy działania
Melatonin, multifunctional signal molecule in mammals: origin, functions, mechanisms of action
Autorzy:
Skwarło-Sońta, Krystyna
Majewski, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/1032921.pdf
Data publikacji:
2010
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
szyszynka
melatonina
receptory
rytm dobowy
przekaźnictwo sygnału
immunomodulacja
zapalenie
pineal gland
melatonin
receptors
circadian rhythm
signal
transduction
immunomodulation
inflammation
Opis:
Methoxyindole hormone - melatonin (MEL) is produced and released by the mammalian pineal gland in a circadian rhythm exhibiting a low level during the day and an elevation at night, strictly dependent on the environmental lighting conditions. The main MEL function is, therefore, to synchronize diurnal rhythms of several physiological processes and for the diurnally active species (including humans) it gives information on the beginning of sleepiness. For the nocturnal species, however, elevated MEL level serves as a signal to start locomotor and feeding activity. In seasonal breeders the pineal gland function synchronizes the time of gonadal development and sexual activity with the external conditions in a way that progeny appears in the optimal climatic moment. MEL is produced also extrapineally, e.g. in the gastro-intestinal tract and bone marrow, where it exerts a protective effect due to its activity as an antioxidant and a potent free radical scavenger. Being both lipid and water soluble, MEL is able to cross biological barriers and, therefore, it uses several cellular mechanism to exert its physiological activity, including membrane and nuclear receptors, proteins of the cytoskeleton, mitochondrial membrane stabilization. MEL is also involved in immunomodulation, the effects are different and dependent on numerous factors, nevertheless, its immunostimulatory activity is generally well accepted. Additionally, activated immune cells are able to produce MEL acting in an auto- and paracrine way. As an efficient antioxidant MEL exerts the anti-inflammatory effect, which, reciprocally, modulates the pineal gland biosynthetic activity adapting it to temporary endogenous conditions.
Szyszynka ssaków produkuje i wydziela do krwi melatoninę (MEL) w rytmie dobowym, którego cechą charakterystyczną jest wysoki poziom w nocy niski w dzień, a czas nocnej syntezy zależy od warunków świetlnych otoczenia. Dzięki temu MEL synchronizuje wiele procesów fizjologicznych przebiegających rytmicznie, a jako chemiczny sygnał ciemności przekazuje gatunkom o aktywności dziennej (w tym ludziom) informację o rozpoczęciu pory snu. Gatunki aktywne w nocy inaczej interpretują sygnał melatoninowy. Dla zwierząt rozmnażających się sezonowo informacja niesiona przez MEL stanowi sygnał do takiej synchronizacji funkcji rozrodczych z warunkami klimatycznymi, aby potomstwo mogło pojawić się w optymalnym momencie. Melatonina powstaje także pozaszyszynkowo, np. w układzie pokarmowym, gdzie pełni funkcje ochronne, związane z aktywnym zmiataniem wolnych rodników i właściwościami antyoksydacyjnymi. Jako cząsteczka amfifilowa może przekraczać bariery biologiczne, dlatego swoje efekty może wywierać za pośrednictwem wielu różnych mechanizmów takich jak: wiązanie z receptorami błonowymi i jądrowymi, białkami cytozolowymi, stabilizowanie błony mitochondrialnej. MEL wykazuje działanie immunomodulacyjne, zależne od wielu czynników, choć zasadniczo wydaje się być czynnikiem wspomagającym odporność, a aktywowane komórki odpornościowe także syntetyzują MEL działającą auto- i parakrynowo. Dzięki właściwościom antyoksydacyjnym pełni istotną rolę przeciwzapalną, z kolei toczący się proces zapalny moduluje aktywność biosyntetyczną szyszynki, dostosowując je do aktualnych warunków w organizmie.
Źródło:
Folia Medica Lodziensia; 2010, 37, 1; 15-55
0071-6731
Pojawia się w:
Folia Medica Lodziensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The ancestry and cumulative evolution of immune reactions
Autorzy:
Dzik, Jolanta
Powiązania:
https://bibliotekanauki.pl/articles/1040306.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
signal transduction
invertebrates
receptors
cytokines
antigen presentation
nitric oxide
phagocytosis
evolution
innate immunity
complement
antibody-based immunity
superoxide
protoza
vertebrates
sponges
Opis:
The last two decades of study enriched greatly our knowledge of how the immune system originated and the sophisticated immune mechanisms of today's vertebrates and invertebrates developed. Even unicellular organisms possess mechanisms for pathogen destruction and self recognition. The ability to distinguish self from non-self is a prerequisite for recognition of sexual compatibility and ensuring survival. Molecules involved in these processes resemble those found in the phagocytic cells of higher organisms. Recognition of bacteria by scavenger receptors induces phagocytosis or endocytosis. The phagocytic mechanisms characterizing the amoeboid protozoans developed further during the evolution towards innate immunity. The scavenger receptor cysteine-rich domain SRCR is encoded in the genomes from the most primitive sponges to mammals. The immune system of sponges comprises signal transduction molecules which occur in higher metazoans as well. Sponges already possess recognition systems for pathogenic bacteria and fungi, based on membrane receptors (a lipopolysaccharide-interacting protein, a cell surface receptor recognizing β(1 → 3)-d-glucans of fungi). Perforin-like molecules and lysozymes are involved, among others, in defense in sponges. Reactive oxygen and nitrogen species function in the immunity of early metazoan. Genes encoding the family of reactive oxygen-generating NADPH oxidases (Noxes) are found in a variety of protists and plants. The NO synthases of cnidarians, mollusks, and chordates are conserved with respect to the mammalian NOS. The antimicrobial peptides of protozoans, amoebapores, are structural and functional analogs of the natural killer cell peptide, NK-lysin, of vertebrates. An ancestral S-type lectin has been found in sponges. Opsonizing properties of lectins and the ability to agglutinate cells justify their classification as primitive recognition molecules. Invertebrate cytokines are not homologous to those of vertebrate, and their functional convergence was presumably enabled by the general similarity of the lectin-like recognition domain three-dimensional structure. Sponges contain molecules with SCR/CCP domains that show high homology to the mammalian regulators of complement activation (RCA family). A multi-component complement system comprising at least the central molecule of the complement system, C3, Factor B, and MASP developed in the cnidarians and evolved into the multilevel cascade engaged in innate and acquired immunity of vertebrates. The adaptive immune system of mammals is also deeply rooted in the metazoan evolution. Some its precursors have been traced as deep as in sponges, namely, two classes of receptors that comprise Ig-like domains, the receptor tyrosine kinases (RTK), and the non-enzymic sponge adhesion molecules (SAM). The antibody-based immune system defined by the presence of the major histocompatibility complex (MHC), T-cell receptor (TCR), B-cell receptor (BCR) or recombination activating genes (RAGs) is known beginning from jawed fishes. However, genes closely resembling RAG1 and RAG2 have been uncovered in the genome of a see urchin. The ancestry of MHC gene remains unknown. Similarly, no homologue of the protein binding domain (PBD) in MHC molecules has been found in invertebrates. The pathway by which endogenous peptides are degraded for presentation with class I MHC molecules utilizes mechanisms similar to those involved in the normal turnover of intracellular proteins, apparently recruited to work also for the immune system. Several cDNAs coding for lysosomal enzymes, e.g., cathepsin, have been isolated from sponges. All chromosomal duplication events in the MHC region occurred after the origin of the agnathans but before the gnathostomes split from them. The V-domains of the subtype found in the receptors of T and B-cells are known from both agnathans and cephalochordates, although they do not rearrange. The rearrangement mechanism of the lymphocyte V-domains suggests its origin from a common ancestral domain existing before the divergence of the extant gnathostome classes. Activation-induced deaminase (AID) - homologous proteins have been found only in the gnathostomes. It appears thus that the adaptive immunity of vertebrates is a result of stepwise accumulation of small changes in molecules, cells and organs over almost half a billion years.
Źródło:
Acta Biochimica Polonica; 2010, 57, 4; 443-466
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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