A variety of glycosylphosphatidylinositol （GPI）-linked proteins are acquired on spermatozoa from epididymal luminal fluids （ELF） during sperm maturation. These proteins serve roles in immunoprotection and in key s...A variety of glycosylphosphatidylinositol （GPI）-linked proteins are acquired on spermatozoa from epididymal luminal fluids （ELF） during sperm maturation. These proteins serve roles in immunoprotection and in key steps of fertilization such as capacitation, acrosomal exocytosis and sperm-egg interactions. Their acquisition on sperm cells is mediated both by membrane vesicles （epididymosomes, EP） which were first reported to dock on the sperm surface, and by lipid carriers which facilitate the transfer of proteins associated with the membrane-free fraction of ELF. While the nonvesicular fraction is more efficient, both pathways are dependent on hydrophobic interactions between the GPI-anchor and the external lipid layer of the sperm surface. More recently proteomic and hypothesis-driven studies have shown that EP from several mammals carry transmembrane （TM） proteins, including plasma membrane Ca^2＋-ATPase 4 （PMCA4）. Synthesized in the testis, PMCA4 is an essential protein and the major Ca^2＋ efflux pump in murine spermatozoa. Delivery of PMCA4 to spermatozoa from bovine and mouse EP during epididymal maturation and in vitro suggests that the docking of EP on the sperm surface precedes fusion, and experimental evidence supports a fusogenic mechanism for TM proteins. Fusion is facilitated by CD9, which generates fusion-competent sites on membranes. On the basis of knowledge of PMCA4＇s interacting partners a number of TM and membrane-associated proteins have been identified or are predicted to be present, in the epididymosomal cargo deliverable to spermatozoa. These Ca^2＋-dependent proteins, undetected in proteomic studies, play essential roles in sperm motility and fertility, and their detection highlights the usefulness of the hypothesis-driven approach.展开更多
Streptococcus equi ssp. zooepidemicus （S. zooepidemicus） is a zoonotic pathogen with worldwide distribution. Lacking suitable vaccine and virulent maker is still bottleneck to control this infection. An immunoproteo...Streptococcus equi ssp. zooepidemicus （S. zooepidemicus） is a zoonotic pathogen with worldwide distribution. Lacking suitable vaccine and virulent maker is still bottleneck to control this infection. An immunoproteomic approach has been used to screen the membrane-associated and cell wall-associated proteins of S. zooepidemicus isolate in China CY to discover vaccine candidate antigens and therapeutic agents. Finally, 11 membrane-associated proteins, and 13 cell wall-associated proteins were successfully identified. BLAST （www.sanger.ac.uk） results also indicated that nucleotide sequences of majority identified proteins shared high homology （60%） with S. zooepidemicus, except for AC1-3, AC5, AC8, and AC13. Moreover, genes for 7 of the identified proteins were detected from CY; compared with ST171, 3 of them （AM1, AM8 and AC11） were only found in virulent strains （CY）. All of the proteins identified in this study remain not to be reported in S. zooepidemicus. Some of the proteins serve a vital role in the immune system and reproduction of host species according to available data, while the functions of the rest were seldom researched.展开更多
CARD recruited membrane associated protein 3 (CARMA3) is a novel scaffold protein. It belongs to the CARMA protein family, and is known to activate nuclear factor (NF)- κB. However, it is still unknown which receptor...CARD recruited membrane associated protein 3 (CARMA3) is a novel scaffold protein. It belongs to the CARMA protein family, and is known to activate nuclear factor (NF)- κB. However, it is still unknown which receptor functions upstream of CARMA3 to trigger NF-κB activation. Recently, several studies have demonstrated that CARMA3 serves as an indispensable adaptor protein in NF-κB signaling under some G protein-coupled receptors (GP- CRs), such as lysophosphatidic acid (LPA) receptor and angiotensin (Ang) Ⅱ receptor. Mechanistically, CARMA3 recruits its essential downstream molecules Bcl10 and MALT1 to form the CBM (CARMA3-Bcl10-MALT1) signalosome whereby it triggers NF-κB activation. GPCRs and NF-κB play pivotal roles in the regulation of various cellular functions, therefore, aberrant regulation of the GPCR/NF-κB signaling axis leads to the development of many types of diseases, such as cancer and atherogenesis. Recently, the GPCR/CARMA3/NF-κB signaling axis has been confirmed in these specific diseases and it plays crucial roles in the pathogenesis of disease progression. In ovarian cancer cell lines, knockdown of CARMA3 abolishes LPA receptor-induced NF-κB activation, and reduces LPA-induced ovarian cancer invasion. In vascular smooth cells, downregulation of CARMA3 substantially impairs Ang-Ⅱ-receptor-induced NF-κB activation, and in vivo studies have confirmed that Bcl10- deficient mice are protected from developing Ang-Ⅱ-receptor-induced atherosclerosis and aortic aneurysms. In this review, we summarize the biology of CARMA3, describe the role of the GPCR/CARMA3/NF-κB signaling axis in ovarian cancer and atherogenesis, and speculate about the potential roles of this signaling axis in other types of cancer and diseases. With a significant increase in the identification of LPA- and Ang-Ⅱ-like ligands, such as endothelin-1, which also activates NF-κB via CARMA3 and contributes to the development of many diseases, CARMA3 is emerging as a novel therapeutic target for various types of cancer an展开更多
文摘A variety of glycosylphosphatidylinositol （GPI）-linked proteins are acquired on spermatozoa from epididymal luminal fluids （ELF） during sperm maturation. These proteins serve roles in immunoprotection and in key steps of fertilization such as capacitation, acrosomal exocytosis and sperm-egg interactions. Their acquisition on sperm cells is mediated both by membrane vesicles （epididymosomes, EP） which were first reported to dock on the sperm surface, and by lipid carriers which facilitate the transfer of proteins associated with the membrane-free fraction of ELF. While the nonvesicular fraction is more efficient, both pathways are dependent on hydrophobic interactions between the GPI-anchor and the external lipid layer of the sperm surface. More recently proteomic and hypothesis-driven studies have shown that EP from several mammals carry transmembrane （TM） proteins, including plasma membrane Ca^2＋-ATPase 4 （PMCA4）. Synthesized in the testis, PMCA4 is an essential protein and the major Ca^2＋ efflux pump in murine spermatozoa. Delivery of PMCA4 to spermatozoa from bovine and mouse EP during epididymal maturation and in vitro suggests that the docking of EP on the sperm surface precedes fusion, and experimental evidence supports a fusogenic mechanism for TM proteins. Fusion is facilitated by CD9, which generates fusion-competent sites on membranes. On the basis of knowledge of PMCA4＇s interacting partners a number of TM and membrane-associated proteins have been identified or are predicted to be present, in the epididymosomal cargo deliverable to spermatozoa. These Ca^2＋-dependent proteins, undetected in proteomic studies, play essential roles in sperm motility and fertility, and their detection highlights the usefulness of the hypothesis-driven approach.
基金supported by the Program for New Century Excellent Talents (NCET) at the University of China (NCET-08-0794)the Key Technology R&D Program of Jiansu Province, China (BE2009388)+1 种基金the Fundamental Research Funds for the Central Universities, China (KYT 201003)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China
文摘Streptococcus equi ssp. zooepidemicus （S. zooepidemicus） is a zoonotic pathogen with worldwide distribution. Lacking suitable vaccine and virulent maker is still bottleneck to control this infection. An immunoproteomic approach has been used to screen the membrane-associated and cell wall-associated proteins of S. zooepidemicus isolate in China CY to discover vaccine candidate antigens and therapeutic agents. Finally, 11 membrane-associated proteins, and 13 cell wall-associated proteins were successfully identified. BLAST （www.sanger.ac.uk） results also indicated that nucleotide sequences of majority identified proteins shared high homology （60%） with S. zooepidemicus, except for AC1-3, AC5, AC8, and AC13. Moreover, genes for 7 of the identified proteins were detected from CY; compared with ST171, 3 of them （AM1, AM8 and AC11） were only found in virulent strains （CY）. All of the proteins identified in this study remain not to be reported in S. zooepidemicus. Some of the proteins serve a vital role in the immune system and reproduction of host species according to available data, while the functions of the rest were seldom researched.
基金Supported by The National Institutes of Health through MD Anderson's Cancer Center Support Grant, No. CA016672
文摘CARD recruited membrane associated protein 3 (CARMA3) is a novel scaffold protein. It belongs to the CARMA protein family, and is known to activate nuclear factor (NF)- κB. However, it is still unknown which receptor functions upstream of CARMA3 to trigger NF-κB activation. Recently, several studies have demonstrated that CARMA3 serves as an indispensable adaptor protein in NF-κB signaling under some G protein-coupled receptors (GP- CRs), such as lysophosphatidic acid (LPA) receptor and angiotensin (Ang) Ⅱ receptor. Mechanistically, CARMA3 recruits its essential downstream molecules Bcl10 and MALT1 to form the CBM (CARMA3-Bcl10-MALT1) signalosome whereby it triggers NF-κB activation. GPCRs and NF-κB play pivotal roles in the regulation of various cellular functions, therefore, aberrant regulation of the GPCR/NF-κB signaling axis leads to the development of many types of diseases, such as cancer and atherogenesis. Recently, the GPCR/CARMA3/NF-κB signaling axis has been confirmed in these specific diseases and it plays crucial roles in the pathogenesis of disease progression. In ovarian cancer cell lines, knockdown of CARMA3 abolishes LPA receptor-induced NF-κB activation, and reduces LPA-induced ovarian cancer invasion. In vascular smooth cells, downregulation of CARMA3 substantially impairs Ang-Ⅱ-receptor-induced NF-κB activation, and in vivo studies have confirmed that Bcl10- deficient mice are protected from developing Ang-Ⅱ-receptor-induced atherosclerosis and aortic aneurysms. In this review, we summarize the biology of CARMA3, describe the role of the GPCR/CARMA3/NF-κB signaling axis in ovarian cancer and atherogenesis, and speculate about the potential roles of this signaling axis in other types of cancer and diseases. With a significant increase in the identification of LPA- and Ang-Ⅱ-like ligands, such as endothelin-1, which also activates NF-κB via CARMA3 and contributes to the development of many diseases, CARMA3 is emerging as a novel therapeutic target for various types of cancer an
