Biological signals and receptors最新文献

{"title":"An updated phylogenetic analysis of vertebrate melatonin receptor sequences: reflection on the melatonin receptor nomenclature by the Nomenclature Subcommittee of the International Union of Pharmacology.","authors":"S Y Shiu,&nbsp;S F Pang","doi":"10.1159/000014549","DOIUrl":"https://doi.org/10.1159/000014549","url":null,"abstract":"<p><p>In the past few years, significant progress on melatonin receptor research has led to the discovery of a family of genetically related but pharmacologically distinctive G-protein-coupled receptors in the vertebrates. With increasing number of receptor clones being identified, there is a need for a system of classification and nomenclature for these receptor subtypes. Recently, an updated nomenclature system, which has renamed the existing mammalian melatonin receptor clones, has been proposed by the relevant subcommittee of the International Union of Pharmacology (NC-IUPHAR). However, the majority of receptor clones which have been identified in non-mammalian vertebrates are not clearly defined by this system. By performing phylogenetic analysis of both mammalian and non-mammalian melatonin receptor clones, we would like to propose a classification-nomenclature system for vertebrate melatonin receptors. Hopefully, our system, which incorporates genetic data as well as the pharmacological criteria that have been adopted by the NC-IUPHAR nomenclature system, will provide the framework for future development of a unified scheme of classification and nomenclature for melatonin receptors.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 4","pages":"244-8"},"PeriodicalIF":0.0,"publicationDate":"1998-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014549","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20644774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Major biological effects of neurotrophic factors on retinal ganglion cells in mammals.","authors":"Q Cui,&nbsp;K F So,&nbsp;H K Yip","doi":"10.1159/000014546","DOIUrl":"https://doi.org/10.1159/000014546","url":null,"abstract":"<p><p>The mammalian visual system, particularly retinal ganglion cells, has been used for studying the functions of neurotrophic factors on neurons for many years. The major biological effects of neurotrophic factors on retinal ganglion cells observed so far are the promotion of viability and axonal regeneration. However, there are still some controversies regarding the effects of neurotrophic factors on retinal ganglion cells in the literature. This review is aimed to summarize the available information on the biological actions of these neurotrophic factors on survival and axonal regeneration of retinal ganglion cells and the expressions of neurotrophic factor receptors in the retina. Generally, brain-derived neurotrophic factor, neurotrophin-4/5, fibroblast growth factor and glial cell line-derived neurotrophic factor increase the survival of retinal ganglion cells while the effect of ciliary neurotrophic factor on the viability of adult retinal ganglion cells is controversial. The ciliary neurotrophic factor is the only effective factor in promoting long distance axonal regeneration of retinal ganglion cells whereas brain-derived neurotrophic factor and neurotrophin-4/5 only enhance neurite sprouting within the retina.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 4","pages":"220-6"},"PeriodicalIF":0.0,"publicationDate":"1998-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014546","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20644768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interleukin-2 and its effects in the central nervous system.","authors":"C L Jiang,&nbsp;C L Lu","doi":"10.1159/000014541","DOIUrl":"https://doi.org/10.1159/000014541","url":null,"abstract":"Interleukin-2 (IL-2) is not only an important immunoregulatory molecule: it is also an important neuroregulatory molecule in the CNS. Investigations in vivo and in vitro have elucidated the following: IL-2 and IL-2 receptors (IL-2R) have been detected in the brain; IL-2 promotes survival and neurite extension of cultured neurons, stimulates oligodendrocyte proliferation and maturation, affects the hypothalamic-pituitary function and produces behavioral and electrocorticogram spectrum changes. Investigations in some laboratories, including ours, have also demonstrated an analgesic effect of IL-2 in the CNS. The molecular structure of the analgesic domain of IL-2 is distinct from the immune domain mediating immunoregulatory effects. A possible mechanism of action of cytokines on the CNS and the immune system or both exists: multiple actions of cytokines could be mediated by distinct domains or functional sites of cytokines interacting with different receptors or receptor subtypes.","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 3","pages":"148-56"},"PeriodicalIF":0.0,"publicationDate":"1998-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014541","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20590063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulation of transferrin function and expression: review and update.","authors":"C N Lok,&nbsp;T T Loh","doi":"10.1159/000014542","DOIUrl":"https://doi.org/10.1159/000014542","url":null,"abstract":"<p><p>The cellular iron uptake is a precisely controlled process to fulfill the iron demand for the synthesis and functions of a variety of iron-containing proteins, and one of the main molecules involved is the transferrin receptor (TfR), which mediates the uptake process via the transferrin cycle. The TfR expression is tightly regulated by factors such as intracellular iron level, cell proliferation or erythropoiesis at levels of receptor recycling, transcriptional or posttranscriptional control. The iron-regulatory protein/iron-responsive element system has been widely used to explain changes in receptor expression during iron loading or depletion, oxidative stress and nitric oxide stimulation. On the other hand, transcriptional control of TfR expression appears to be more important in erythroid differentiation and general cell proliferation. There is also an increasing awareness of the clinical application and experimental therapeutics based on the TfR functioning and expression. In this review, we attempt to provide a concise account of the studies of TfR structure and function as well as those areas that have not been reviewed in depth, in particular, tissue-specific regulation of TfR, the molecular mechanisms of TfR expression, and the use of TfR as diagnostic and therapeutic tools. The regulation of TfR expression in various tissues is related to its specific cellular iron requirements. Hemoglobin-synthesizing cells exhibit distinct features of iron metabolism and TfR expression as compared to most non-erythroid cells which synthesize a much lower amount of heme. For most non-erythroid cells, iron can regulate the TfR expression in a reciprocal manner through modulating the stability of the receptor mRNA whereas in hemoglobin-synthesizing cells, the TfR expression is independent of the cellular iron loading. In spite of a wide heterogeneity in the way receptor redistribution is in response to various stimuli, regulation of the constitutive expression of TfR is one of the ways of regulating the cellular iron uptake. This expression operates on both transcriptional and posttranscriptional levels. In general, factors related to cell growth and differentiation operate on the gene transcription level, whereas iron regulates the fate of the mature mRNA.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 3","pages":"157-78"},"PeriodicalIF":0.0,"publicationDate":"1998-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014542","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20590065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The hair follicle: a specialised UV receptor in the human skin?","authors":"B Iyengar","doi":"10.1159/000014544","DOIUrl":"https://doi.org/10.1159/000014544","url":null,"abstract":"<p><p>Coat colour changes in polar animals are related to seasonal variation in photic inputs. The present work was performed to study the photoresponses of hair follicular melanocytes in human skin. The melanocytes, being photosensitive cells, can function as UV biosensors, since dendrites extend towards the source of UV light. Fifty-one skin biopsies from the margin of vitiligo were subjected to whole skin organ cultures. These were exposed to a pulse of UV light to study hair bulb melanocytes in vitiligo. It is observed that the melanocytes are seen within the anagen matrix. These melanocytes are poorly dendritic in control and dark-incubated cultures. On UV exposure, they become highly dendritic, the dendrites extending towards the hair shaft in 93.5%. They show prominent catechol oxidase and noradrenaline positivity, all features of UV responsiveness. The melanocytes within the hair follicle are not directly exposed to UV light. The melanocyte dendricity and the alignment of dendrites towards the shaft on UV exposure indicate that the columns of the cells in the hair shaft act as an efficient fibre-optic system, transmitting UV light. Morphologically, the keratinocytes in the hair shaft are arranged in compressed linear columns which resemble the coaxial bundles of commercial fibre-optic strands as is observed in plants. Keratinocytes in the inner and outer sheaths do not show this arrangement. Thus the hair follicle functions as a specialised UV receptor in the skin responding to nuances of photic inputs in human skin. This is reflected in coat colour changes in animals exposed to large variations in day-night cycles.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 3","pages":"188-94"},"PeriodicalIF":0.0,"publicationDate":"1998-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014544","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20590068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear calcium: transfer to and from the cytosol.","authors":"J R MacDonald","doi":"10.1159/000014540","DOIUrl":"https://doi.org/10.1159/000014540","url":null,"abstract":"<p><p>Although the cell nucleus is known to control much of cell function, little is known as to the mediator of such function. Recent evidence has suggested that Ca2+ may be responsible for the regulation of many nuclear events. Early investigations have reported that the nucleus may be able to control its calcium function independently of the adjacent cytosol. IP3 and IP4 may act as regulators of nuclear Ca2+ independently or in parallel with the cytosol. This paper examines the current state of knowledge regarding nuclear calcium regulation. Additionally, a model for this regulation is proposed.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 3","pages":"137-47"},"PeriodicalIF":0.0,"publicationDate":"1998-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014540","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20590689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exposure to different spectra of light, continuous light and treatment with melatonin affect reproduction in the Indian desert gerbil Meriones hurrianae (Jerdon).","authors":"S V Sinhasane,&nbsp;B N Joshi","doi":"10.1159/000014543","DOIUrl":"https://doi.org/10.1159/000014543","url":null,"abstract":"<p><p>In two separate experiments, the gonadal response to melatonin treatment and exposure to continuous white light (LL) and different spectra of light (blue, green, yellow and red) was investigated in the Indian desert gerbil Meriones hurrianae. In experiment 1, exposure to green light for 8 weeks increased (p < 0.01) the gonadosomatic index (GSI) and sperm count, whereas exposure to red light decreased (p < 0.01) the GSI and sperm count. The response of accessory organs to the treatment varied. In experiment 2, exposure to LL for 5 weeks decreased the GSI and sperm count, and treatment with melatonin (in the late-light period) not only increased the GSI and sperm count, but also counteracted the inhibitory action of LL and red light. Melatonin treatment stimulated accessory sex organs and the scent gland surface area. The inhibition or stimulation of the reproductive parameters correlated with an increase or decrease in pinealocytes and pinealocyte nuclear diameters. Therefore, the influence of light and its spectra on reproduction may be mediated by the pineal gland, though extrapineal mechanisms cannot be ruled out.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 3","pages":"179-87"},"PeriodicalIF":0.0,"publicationDate":"1998-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014543","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20590067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The evidence for G-protein-coupled receptors and heterotrimeric G proteins in protozoa and ancestral metazoa.","authors":"D C New,&nbsp;J T Wong","doi":"10.1159/000014535","DOIUrl":"https://doi.org/10.1159/000014535","url":null,"abstract":"<p><p>In higher eukaryotes G-protein-coupled signal transduction pathways are a common mechanism used to detect an extracellular message and transmit a signal, via a membrane-bound receptor and a heterotrimeric G protein, to second messenger producing enzymes and effector proteins. The techniques used to identify components of these pathways are increasingly being applied to protozoa and ancestral metazoa. Many of the organisms studied do seem to express functional homologues of those found in higher eukaryotes and increasingly genes encoding these proteins are being cloned. Sequence analysis of the isolated alpha-subunits of heterotrimeric G proteins shows that these proteins have extensive homology to their mammalian counterparts, and often show absolute sequence identity in functionally significant regions. The receptor clones isolated clearly establish that protozoa and early metazoa express proteins with seven transmembrane spanning domains. Comparisons with mammalian receptors indicate that these proteins are likely to be regulated by phosphorylation and dephosphorylation events, although the pathways which control these are yet to be identified. The postulated regulatory mechanisms and the number of homologous clones isolated from some protozoa suggest that a highly regulated system of transmembrane signalling appeared at a relatively early stage in evolution.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 2","pages":"98-108"},"PeriodicalIF":0.0,"publicationDate":"1998-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014535","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20548848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lipid modifications and membrane targeting of G alpha.","authors":"P B Wedegaertner","doi":"10.1159/000014538","DOIUrl":"https://doi.org/10.1159/000014538","url":null,"abstract":"<p><p>G protein alpha-subunits (G alpha) undergo palmitoylation and/or myristoylation. This review will focus on new insights into the function and regulation of these fatty acid modifications of G alpha. Most importantly, I will examine lipid modifications of G alpha in the context of a two-signal model for membrane attachment, discuss recent advances in the identification of palmitoyl transferases, and highlight several controversial issues in this field.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 2","pages":"125-35"},"PeriodicalIF":0.0,"publicationDate":"1998-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014538","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20548154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"G-protein-coupled receptors in vascular smooth muscle cells.","authors":"C D Demoliou-Mason","doi":"10.1159/000014534","DOIUrl":"https://doi.org/10.1159/000014534","url":null,"abstract":"<p><p>Vasoactive peptides like thrombin, angiotensin II and endothelin induce vascular smooth muscle cell (VSMC) contraction via activation of G-protein-coupled receptors. Recent studies have shown that they also induce VSMC migration and proliferation, processes which are important in the remodelling of the vasculature during embryogenesis and in the response to vascular injury. G-protein-coupled receptor-mediated mitogenic signals appear to be transmitted via a number of intracellular mechanisms which include proto-oncogene gene expression, G-protein-mediated protein translocation and tyrosine phosphorylation of growth factor receptor proteins, and activation of autocrine growth factor pathways. The ability of vasoactive peptides to have an impact on signalling cascades mediated by growth factor tyrosine kinase receptors may be important in the pathogenesis of diseases in the vasculature.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"7 2","pages":"90-7"},"PeriodicalIF":0.0,"publicationDate":"1998-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014534","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20548846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}