Objective: To construct mammalian cell expression vectors for Mac-1 with CFP and YFP and apply FRET to study the dimerization and function of CD11 b( Mac-1 α subunit) and CD18(Mac-1 β subunit). Methods: The mammalia...Objective: To construct mammalian cell expression vectors for Mac-1 with CFP and YFP and apply FRET to study the dimerization and function of CD11 b( Mac-1 α subunit) and CD18(Mac-1 β subunit). Methods: The mammalian cell expression vector for CD11b fused with CFP at the carboxyl terminal was constructed to create recombinant plasmid of pCD11b-CFP. Then pCD11b-CFP was co-transfected with pYFP-CD18 into CHO cell, a fibroblast like cell line, as a target cell within which there are some signal pathways involved in inflammatory stimulation but without endogenous Mac-1. Then CHO cells stably expressing both CD11b-CFP and YFP-CD18 fusion proteins were selected by Western blot and laser scanning confocal microscope. Results: The cyan and yellow fluorescence in co-transfected positive CHO cells were observed under a fluorescence microscope. CHO-Mac-1-FP cells stably expressing both CD11b-CFP and YFP-CD18 fusion proteins were obtained as demonstrated by Western blot successfully. The adhesive activity of CHO-Mac-1-FP cells with CHO-1CAM-1 cells was increased markedly by treatment with PMA, suggesting the translocation of GD11b-CFP and YFP-CD18 to the plasma membrane in CHO-Mac-1-FP cells and dimerization of CD11b-CFP and YFP-CD18 just as the function of the wild type Mac-1. Conclusion: CHO-Mac-1-FP cells with adhesive activity are established successfully, thus CHO-Mac-1-FP cells may be useful for the study of Mac-1 by FRET and for other purposes.展开更多
The function of the herpes simplex virus type 1 （HSV-1） UL4 protein is still elusive. Our objective is to investigate the subcellular transport mechanism of the UL4 protein. In this study, fluorescence microscopy wa...The function of the herpes simplex virus type 1 （HSV-1） UL4 protein is still elusive. Our objective is to investigate the subcellular transport mechanism of the UL4 protein. In this study, fluorescence microscopy was employed to investigate the subcellular localization of UL4 and characterize the transport mechanism in living cells. By constructing a series of deletion mutants fused with enhanced yellow fluorescent protein （EYFP）, the nuclear export signals （NES） of UL4 were for the first time mapped to amino acid residues 178 to 186. In addition, the N-terminal 19 amino acids are identified to be required for the granule-like cytoplasmic pattem of UL4. Furthermore, the UL4 protein was demonstrated to be exported to the cytoplasm through the NES in a chromosomal region maintenance 1 （CRM1）-dependent manner involving RanGTP hydrolysis展开更多
基金Supported by National Natural Science Foundation of China (No.30000068, 39730210)
文摘Objective: To construct mammalian cell expression vectors for Mac-1 with CFP and YFP and apply FRET to study the dimerization and function of CD11 b( Mac-1 α subunit) and CD18(Mac-1 β subunit). Methods: The mammalian cell expression vector for CD11b fused with CFP at the carboxyl terminal was constructed to create recombinant plasmid of pCD11b-CFP. Then pCD11b-CFP was co-transfected with pYFP-CD18 into CHO cell, a fibroblast like cell line, as a target cell within which there are some signal pathways involved in inflammatory stimulation but without endogenous Mac-1. Then CHO cells stably expressing both CD11b-CFP and YFP-CD18 fusion proteins were selected by Western blot and laser scanning confocal microscope. Results: The cyan and yellow fluorescence in co-transfected positive CHO cells were observed under a fluorescence microscope. CHO-Mac-1-FP cells stably expressing both CD11b-CFP and YFP-CD18 fusion proteins were obtained as demonstrated by Western blot successfully. The adhesive activity of CHO-Mac-1-FP cells with CHO-1CAM-1 cells was increased markedly by treatment with PMA, suggesting the translocation of GD11b-CFP and YFP-CD18 to the plasma membrane in CHO-Mac-1-FP cells and dimerization of CD11b-CFP and YFP-CD18 just as the function of the wild type Mac-1. Conclusion: CHO-Mac-1-FP cells with adhesive activity are established successfully, thus CHO-Mac-1-FP cells may be useful for the study of Mac-1 by FRET and for other purposes.
基金the Major State Basic Research Development Program of China(2010CB530105 and 2011CB504802)the National Natural Science Foundation of China(30900059,30870120 and 81000736)the Start-up Fund of the Hundred Talents Program of the Chinese Academy of Sciences(20071010-141)
文摘The function of the herpes simplex virus type 1 （HSV-1） UL4 protein is still elusive. Our objective is to investigate the subcellular transport mechanism of the UL4 protein. In this study, fluorescence microscopy was employed to investigate the subcellular localization of UL4 and characterize the transport mechanism in living cells. By constructing a series of deletion mutants fused with enhanced yellow fluorescent protein （EYFP）, the nuclear export signals （NES） of UL4 were for the first time mapped to amino acid residues 178 to 186. In addition, the N-terminal 19 amino acids are identified to be required for the granule-like cytoplasmic pattem of UL4. Furthermore, the UL4 protein was demonstrated to be exported to the cytoplasm through the NES in a chromosomal region maintenance 1 （CRM1）-dependent manner involving RanGTP hydrolysis
