In insects,the sense of smell is mainly mediated by olfactory receptors（Ors）.Olfactory co-receptor（Orco）,which is coexpressed with the Ors in almost all olfactory receptor neurons（ORNs）,is demonstrated to be an ...In insects,the sense of smell is mainly mediated by olfactory receptors（Ors）.Olfactory co-receptor（Orco）,which is coexpressed with the Ors in almost all olfactory receptor neurons（ORNs）,is demonstrated to be an essential component in the insect olfactory system.It can be potential target for developing novel olfactory-disruption strategy to control insect pests.In this study,two full-length cDNA sequences encoding Orcos（CmedOrco and ChsupOrco） were cloned from two Lepidopteran rice pests,the rice leaffolder,Cnaphalocrocis medinalis and the rice striped stem borer,Chilo suppressalis.The amino acid sequences of CmedOrco and ChsupOrco showed high similarity to the previously identified Orcos from other insect species. Bioinformatic prediction and cellular immunofluorescence indicated that CmedOrco and ChsupOrco were both seven-transmembrane proteins with intracellular N-termini and extracellular C-termini.mRNA expression levels of the two Orcos were much higher in male and female antennae than those in non-olfactory tissues,and the ChsupOrco transcripts reached a peak level in adults compared to other life stages.Our results provide a foundation from which it will be possible to elucidate the roles of Orco in moth olfaction and for the development of environment-friendly management strategies of these two rice insect pests.展开更多
In Arabidopsis, the CLAVATA3/EMBRYO SURROUNDING REGION-RELATED （CLE） peptides play important roles in regulating proliferation and differentiation of plant-specific stem cells. Although receptors of CLEs are reporte...In Arabidopsis, the CLAVATA3/EMBRYO SURROUNDING REGION-RELATED （CLE） peptides play important roles in regulating proliferation and differentiation of plant-specific stem cells. Although receptors of CLEs are reported to be leucine-rich repeat receptor kinases, the mechanisms underlying CLE-induced receptor activation remain largely unknown. Here we show that SOMATIC EMBRYOGENESIS RECEPTOR KINASEs （SERKs） serve as co-receptors in CLE41/TDIF-PXY signaling to regulate plant vascular development. TDIF induces interaction of its receptor PXY with SERKs in vitro and in vivo. Furthermore, the serk1-1 serk2-1 bakl-5 mutant plants are less sensitive to TDIF, phenocopying the pxy mutant with a compromised promotion of procambial cell proliferation. Crystal structure of the PXY-TDIF-SERK2 complex reveals that the last amino acid of TDIF conserved among CLEs and other evolutionary-related peptides is important for the interaction between SERK2 and PXY. Taken together, our current study identifies SERKs as signaling components of the TDIF-PXY pathway and suggests a conserved activation mechanism of CLE receptors.展开更多
The function and usage of vMIPα encoded by K6 gene of herpesvirus 8 (HHV8) which has homology with human macrophage protein (MIP) have not been clearly known. In the present note the K6 gene of HHV8 was cloned and tr...The function and usage of vMIPα encoded by K6 gene of herpesvirus 8 (HHV8) which has homology with human macrophage protein (MIP) have not been clearly known. In the present note the K6 gene of HHV8 was cloned and transfected into NIH3T3 cells and E. coli cells. Conditional media from the 3T3-transfected cells and K6 product vMIPa from E. coli. Cells were used to perform the experiments of ligand-receptor binding and cellular adhesion with peripheral blood macrophages. The conditional media and the purified vMIPa from E. coli could compete to bind to CCR5 located on macrophages from peripheral blood with I125-hMIP-1α chemokine of human. Cellular adhesion showed that the conditional media from transfected cells and the purified vMIPa did not induce the adhesion of macrophages from peripheral blood to ICAM-1. In conclusion, vMIPα encoded by K6 gene of HHV8 can bind to CCR5 of peripheral blood macrophage cells and does not induce their adhesion. This suggests that vMIPa enclosed CCR5, also known as HIV展开更多
HIV-1 co-receptor tropism is central for understanding the transmission and pathogenesis of HIV-1 infection. We performed a genome-wide comparison between the adaptive evolution of R5 and X4 variants from HIV-1 subtyp...HIV-1 co-receptor tropism is central for understanding the transmission and pathogenesis of HIV-1 infection. We performed a genome-wide comparison between the adaptive evolution of R5 and X4 variants from HIV-1 subtypes B and C. The results showed that R5 and X4 variants experienced differential evolutionary patterns and different HIV-1 genes encountered various positive selection pressures, suggesting that complex selection pressures are driving HIV-1 evolution. Compared with other hypervariable regions of Gp120, significantly more positively selected sites were detected in the V3 region of subtype B X4 variants, V2 region of subtype B R5 variants, and V1 and V4 regions of subtype C X4 variants, indicating an association of positive selection with co-receptor recognition/binding. Intriguingly, a significantly higher proportion (33.3% and 55.6%, P【0.05) of positively selected sites were identified in the C3 region than other conserved regions of Gp120 in all the analyzed HIV-1 variants, indicating that the C3 region might be more important to HIV-1 adaptation than previously thought. Approximately half of the positively selected sites identified in the env gene were identical between R5 and X4 variants. There were three common positively selected sites (96, 113 and 281) identified in Gp41 of all X4 and R5 variants from subtypes B and C. These sites might not only suggest a functional importance in viral survival and adaptation, but also imply a potential cross-immunogenicity between HIV-1 R5 and X4 variants, which has important implications for AIDS vaccine development.展开更多
CD8 is a cell surface glycoprotein found in cytotoxic T lymphocytes,which are important components in cellular immunity,esp.in the immune response to cancer and chronic infections.There are two forms of CD8, either as...CD8 is a cell surface glycoprotein found in cytotoxic T lymphocytes,which are important components in cellular immunity,esp.in the immune response to cancer and chronic infections.There are two forms of CD8, either as an αα homodimer or αβ heterodimer.It acts as an“assistant”or co-receptor in the function of cytotoxic T cells where specific immunity is mediated by interaction of specific T cell receptor(αβTCR)and its ligand peptide major histocompatibility complex(pMHC).CD8 also binds to pMHC but away from the interface of pMHC and TCR contact,thereof no influence on the specificity of this interaction.If the TCR and CD8 bind to the same pMHC at the same time,CD8 is defined as a co-receptor,functioning through its signalling via its cytoplasmic tyrosine phosphorylation pathway;if CD8 binds to pMHC independently of the TCR,it is defined as an adhesion molecule.At present,the co-receptor function theory is dominated in the field. Recent study has also shown that murine CD8αα binds to TL antigen,an MHC homologue,therefore acts as an immuno-modulator.In this review,we discuss these current understandings of the three aspects of the CD8 functions and their structural basis.Cellular & Molecular Immunology.2004;1(2):81-88.展开更多
In order to explore the functions of retinol binding protein (RBP4) in regulation of gene expression, yeast two hybrid assay and transient co-transforming were used to detect the interactions between RBP4 and nuclear ...In order to explore the functions of retinol binding protein (RBP4) in regulation of gene expression, yeast two hybrid assay and transient co-transforming were used to detect the interactions between RBP4 and nuclear receptors and the effects of over-expressed RBP4 on trans-activation functions of human estrogen receptor related receptor 1 (hERR1) and human estrogen (hER). The requirement of activation function domain-2 (AF-2) for hER to interact with RBP4 was also detected by the yeast two hybrid assay. The results show that RBP4 could interact with many nuclear receptors including mouse estrogen receptor related receptor 3 (mERR3), retinoid X receptor (RXR), glucocorticoid receptor (GR), progestin receptor (PR), and androgen receptor (AR) in yeast cells. Over-expressed RBP4 could strongly enhance the trans-activation functions of hERR1 and hER in a dose-dependent manner, respectively. RBP4 could also interact with hER in an AF-2-dependent manner.展开更多
基金funded by the Industry Project of Ministry of Agriculture of China(200903051)the National Natural Science Foundation of China(30900149)
文摘In insects,the sense of smell is mainly mediated by olfactory receptors（Ors）.Olfactory co-receptor（Orco）,which is coexpressed with the Ors in almost all olfactory receptor neurons（ORNs）,is demonstrated to be an essential component in the insect olfactory system.It can be potential target for developing novel olfactory-disruption strategy to control insect pests.In this study,two full-length cDNA sequences encoding Orcos（CmedOrco and ChsupOrco） were cloned from two Lepidopteran rice pests,the rice leaffolder,Cnaphalocrocis medinalis and the rice striped stem borer,Chilo suppressalis.The amino acid sequences of CmedOrco and ChsupOrco showed high similarity to the previously identified Orcos from other insect species. Bioinformatic prediction and cellular immunofluorescence indicated that CmedOrco and ChsupOrco were both seven-transmembrane proteins with intracellular N-termini and extracellular C-termini.mRNA expression levels of the two Orcos were much higher in male and female antennae than those in non-olfactory tissues,and the ChsupOrco transcripts reached a peak level in adults compared to other life stages.Our results provide a foundation from which it will be possible to elucidate the roles of Orco in moth olfaction and for the development of environment-friendly management strategies of these two rice insect pests.
基金This research was funded by Projects of International Cooperation and Exchanges NSFC （31420103906）, the National Science Foundation of China （31130063 and 31421001） and the Chinese Ministry of Science and Technology （2015CB910200） to J.C and the National Science Foun- dation of China （31370173） to L.Q.ACKNOWLEDGEMENTS We thank Jianhua He at Shanghai Synchrotron Radiation Facility （SSRF） for assistance with X-ray data collection, Dr. Hiroo Fukuda （Tokyo University, Japan） for the pxy-5 single mutant seeds, Dr. Libo Shah （Texas A＆M University） for serk1-1 serk2-1^＋/- bakl-5 mutant seeds, and Dr. Jia Li for other serk mutant seeds, SERK1, SERK2 entry vectors, and pSERKI： SERK1-GFP vector. No conflict of interest declared.
文摘In Arabidopsis, the CLAVATA3/EMBRYO SURROUNDING REGION-RELATED （CLE） peptides play important roles in regulating proliferation and differentiation of plant-specific stem cells. Although receptors of CLEs are reported to be leucine-rich repeat receptor kinases, the mechanisms underlying CLE-induced receptor activation remain largely unknown. Here we show that SOMATIC EMBRYOGENESIS RECEPTOR KINASEs （SERKs） serve as co-receptors in CLE41/TDIF-PXY signaling to regulate plant vascular development. TDIF induces interaction of its receptor PXY with SERKs in vitro and in vivo. Furthermore, the serk1-1 serk2-1 bakl-5 mutant plants are less sensitive to TDIF, phenocopying the pxy mutant with a compromised promotion of procambial cell proliferation. Crystal structure of the PXY-TDIF-SERK2 complex reveals that the last amino acid of TDIF conserved among CLEs and other evolutionary-related peptides is important for the interaction between SERK2 and PXY. Taken together, our current study identifies SERKs as signaling components of the TDIF-PXY pathway and suggests a conserved activation mechanism of CLE receptors.
基金This work was supported by the National "863" Program (Grant No. G0208070599) the Guangdong Provincial Natural Science Foundation (Grant No. 990470) and the National Natural Science Foundation of China (Grant No. 30070697).
文摘The function and usage of vMIPα encoded by K6 gene of herpesvirus 8 (HHV8) which has homology with human macrophage protein (MIP) have not been clearly known. In the present note the K6 gene of HHV8 was cloned and transfected into NIH3T3 cells and E. coli cells. Conditional media from the 3T3-transfected cells and K6 product vMIPa from E. coli. Cells were used to perform the experiments of ligand-receptor binding and cellular adhesion with peripheral blood macrophages. The conditional media and the purified vMIPa from E. coli could compete to bind to CCR5 located on macrophages from peripheral blood with I125-hMIP-1α chemokine of human. Cellular adhesion showed that the conditional media from transfected cells and the purified vMIPa did not induce the adhesion of macrophages from peripheral blood to ICAM-1. In conclusion, vMIPα encoded by K6 gene of HHV8 can bind to CCR5 of peripheral blood macrophage cells and does not induce their adhesion. This suggests that vMIPa enclosed CCR5, also known as HIV
基金supported by the National Natural Science Foundation of China (Grant No. 30600352)the "Top-notch Personnel" Project of Ji-angsu University, the National Basic Research Program of China (Grant No. 2006CB504200)the Open Research Fund Program of the State Key Laboratory of Virology of China (Grant No. 2009008)
文摘HIV-1 co-receptor tropism is central for understanding the transmission and pathogenesis of HIV-1 infection. We performed a genome-wide comparison between the adaptive evolution of R5 and X4 variants from HIV-1 subtypes B and C. The results showed that R5 and X4 variants experienced differential evolutionary patterns and different HIV-1 genes encountered various positive selection pressures, suggesting that complex selection pressures are driving HIV-1 evolution. Compared with other hypervariable regions of Gp120, significantly more positively selected sites were detected in the V3 region of subtype B X4 variants, V2 region of subtype B R5 variants, and V1 and V4 regions of subtype C X4 variants, indicating an association of positive selection with co-receptor recognition/binding. Intriguingly, a significantly higher proportion (33.3% and 55.6%, P【0.05) of positively selected sites were identified in the C3 region than other conserved regions of Gp120 in all the analyzed HIV-1 variants, indicating that the C3 region might be more important to HIV-1 adaptation than previously thought. Approximately half of the positively selected sites identified in the env gene were identical between R5 and X4 variants. There were three common positively selected sites (96, 113 and 281) identified in Gp41 of all X4 and R5 variants from subtypes B and C. These sites might not only suggest a functional importance in viral survival and adaptation, but also imply a potential cross-immunogenicity between HIV-1 R5 and X4 variants, which has important implications for AIDS vaccine development.
文摘CD8 is a cell surface glycoprotein found in cytotoxic T lymphocytes,which are important components in cellular immunity,esp.in the immune response to cancer and chronic infections.There are two forms of CD8, either as an αα homodimer or αβ heterodimer.It acts as an“assistant”or co-receptor in the function of cytotoxic T cells where specific immunity is mediated by interaction of specific T cell receptor(αβTCR)and its ligand peptide major histocompatibility complex(pMHC).CD8 also binds to pMHC but away from the interface of pMHC and TCR contact,thereof no influence on the specificity of this interaction.If the TCR and CD8 bind to the same pMHC at the same time,CD8 is defined as a co-receptor,functioning through its signalling via its cytoplasmic tyrosine phosphorylation pathway;if CD8 binds to pMHC independently of the TCR,it is defined as an adhesion molecule.At present,the co-receptor function theory is dominated in the field. Recent study has also shown that murine CD8αα binds to TL antigen,an MHC homologue,therefore acts as an immuno-modulator.In this review,we discuss these current understandings of the three aspects of the CD8 functions and their structural basis.Cellular & Molecular Immunology.2004;1(2):81-88.
文摘In order to explore the functions of retinol binding protein (RBP4) in regulation of gene expression, yeast two hybrid assay and transient co-transforming were used to detect the interactions between RBP4 and nuclear receptors and the effects of over-expressed RBP4 on trans-activation functions of human estrogen receptor related receptor 1 (hERR1) and human estrogen (hER). The requirement of activation function domain-2 (AF-2) for hER to interact with RBP4 was also detected by the yeast two hybrid assay. The results show that RBP4 could interact with many nuclear receptors including mouse estrogen receptor related receptor 3 (mERR3), retinoid X receptor (RXR), glucocorticoid receptor (GR), progestin receptor (PR), and androgen receptor (AR) in yeast cells. Over-expressed RBP4 could strongly enhance the trans-activation functions of hERR1 and hER in a dose-dependent manner, respectively. RBP4 could also interact with hER in an AF-2-dependent manner.
