BACKGROUND Colorectal cancer(CRC) is a common malignancy of the gastrointestinal tract. The worldwide mortality rate of CRC is about one half of its morbidity. Ubiquitin is a key regulatory factor in the cell cycle an...BACKGROUND Colorectal cancer(CRC) is a common malignancy of the gastrointestinal tract. The worldwide mortality rate of CRC is about one half of its morbidity. Ubiquitin is a key regulatory factor in the cell cycle and widely exists in eukaryotes. Human leukocyte antigen F-associated transcript 10(FAT10), known as diubiquitin, is an 18 kDa protein with 29% and 36% homology with the N and C termini of ubiquitin. The function of FAT10 has not been fully elucidated, and some studies have shown that it plays an important role in various cell processes.AIM To examine FAT10 expression and to analyze the relationship between FAT10 expression and the clinicopathological parameters of CRC.METHODS FAT10 expression in 61 cases of CRC and para-cancer colorectal tissues was measured by immunohistochemistry and Western blotting. The relationship between FAT10 expression and clinicopathological parameters of CRC was statistically analyzed.RESULTS Immunohistochemical analysis showed that the positive rate of FAT10 expression in CRC(63.93%) was significantly higher than that in tumor-adjacent tissues(9.84%, P < 0.05) and normal colorectal mucosal tissue(1.64%, P < 0.05). Western blotting also indicated that FAT10 expression was significantly higher in CRC than in tumor-adjacent tissue(P < 0.05). FAT10 expression was closely associated with clinical stage and lymphatic spread of CRC. FAT10 expression also positively correlated with p53 expression.CONCLUSION FAT10 expression is highly upregulated in CRC. FAT10 expression is closely associated with clinical stage and lymphatic spread of CRC.展开更多
Ubiquitin-fold modifier 1（UFM1） is one of the newly-identified ubiquitin-like proteins.Similar to ubiquitin,UFM1 is conjugated to its target proteins by a three-step enzymatic reaction.The UFM1-activating enzyme,ubi...Ubiquitin-fold modifier 1（UFM1） is one of the newly-identified ubiquitin-like proteins.Similar to ubiquitin,UFM1 is conjugated to its target proteins by a three-step enzymatic reaction.The UFM1-activating enzyme,ubiquitin-like modifier-activating enzyme 5（UBA5）,serves as the E1 to activate UFM1;UFM1-conjugating enzyme 1（UFC1） acts as the E2 to transfer the activated UFM1 to the active site of the E2;and the UFM1-specific ligase 1（UFL1） acts as the E3 to recognize its substrate,transfer,and ligate the UFM1 from E2 to the substrate.This process is called ufmylation.UFM1 chains can be cleaved from its target proteins by UFM1-specific proteases（Uf SPs）,suggesting that the ufmylation modification is reversible.UFM1 cascade is conserved among nearly all of the eukaryotic organisms,but not in yeast,and associated with several cellular activities including the endoplasmic reticulum stress response and hematopoiesis.Furthermore,the UFM1 cascade is closely related to a series of human diseases.In this review,we summarize the molecular details of this reversible modification process,the recent progress of its functional studies,as well as its implication in tumorigenesis and potential therapeutic targets for cancer.展开更多
We identified a novel ubiquitin-like molecule DULP from human dendritic cells. DULP contains a domain that shares 26% identity and 34% similarity with ubiquitin, and it possesses the corresponding Ile-44 hydrophobic p...We identified a novel ubiquitin-like molecule DULP from human dendritic cells. DULP contains a domain that shares 26% identity and 34% similarity with ubiquitin, and it possesses the corresponding Ile-44 hydrophobic patch used by mono- or poly-ubiquitin to interact with a ubiquitin-interaction motif （UIM） or ubiquitin-associated domain （UBA）. Lysine residue corresponding to 6 of ubiquitin, which is involved in the formation of a multi-ubiquitin chain that can bind proteasomal subunit Rpn10/S5a, is also conserved in its ubiquitin-homology domain. However, DULP does not possess the highly conserved C-terminus Gly-Gly required for ubiquitin conjugation or the Lys-48 required for the formation of polyubiquitin chain to target substrates for degradation, suggesting it might be a novel ubiquitin-domain protein （UDP）. DULP was found widely expressed in many cells and the ubiquitin-homology domain was not cleaved. We also confirmed that DULP expression was enriched in the nucleus and much weaker in the cytosol. Besides, we found that overexpression of DULP in 293T cells induced apoptosis, which might not be associated with the mitochondrial or proteasome pathway, with the specific mechanism remain unclear. Further investigations are needed to identify the precise biological functions of DULP. Cellular ＆ Molecular Immunology.展开更多
文摘BACKGROUND Colorectal cancer(CRC) is a common malignancy of the gastrointestinal tract. The worldwide mortality rate of CRC is about one half of its morbidity. Ubiquitin is a key regulatory factor in the cell cycle and widely exists in eukaryotes. Human leukocyte antigen F-associated transcript 10(FAT10), known as diubiquitin, is an 18 kDa protein with 29% and 36% homology with the N and C termini of ubiquitin. The function of FAT10 has not been fully elucidated, and some studies have shown that it plays an important role in various cell processes.AIM To examine FAT10 expression and to analyze the relationship between FAT10 expression and the clinicopathological parameters of CRC.METHODS FAT10 expression in 61 cases of CRC and para-cancer colorectal tissues was measured by immunohistochemistry and Western blotting. The relationship between FAT10 expression and clinicopathological parameters of CRC was statistically analyzed.RESULTS Immunohistochemical analysis showed that the positive rate of FAT10 expression in CRC(63.93%) was significantly higher than that in tumor-adjacent tissues(9.84%, P < 0.05) and normal colorectal mucosal tissue(1.64%, P < 0.05). Western blotting also indicated that FAT10 expression was significantly higher in CRC than in tumor-adjacent tissue(P < 0.05). FAT10 expression was closely associated with clinical stage and lymphatic spread of CRC. FAT10 expression also positively correlated with p53 expression.CONCLUSION FAT10 expression is highly upregulated in CRC. FAT10 expression is closely associated with clinical stage and lymphatic spread of CRC.
基金supported by the National Natural Science Foundation of China (NSFCGrant Nos.31530016 and 31461143012)+2 种基金the National Basic Research Program of China (973 ProgramGrant Nos.2013CB911002 and 2015CB910601)the Scientific Research Base Development Program of the Beijing Municipal Commission of Education,China to XX
文摘Ubiquitin-fold modifier 1（UFM1） is one of the newly-identified ubiquitin-like proteins.Similar to ubiquitin,UFM1 is conjugated to its target proteins by a three-step enzymatic reaction.The UFM1-activating enzyme,ubiquitin-like modifier-activating enzyme 5（UBA5）,serves as the E1 to activate UFM1;UFM1-conjugating enzyme 1（UFC1） acts as the E2 to transfer the activated UFM1 to the active site of the E2;and the UFM1-specific ligase 1（UFL1） acts as the E3 to recognize its substrate,transfer,and ligate the UFM1 from E2 to the substrate.This process is called ufmylation.UFM1 chains can be cleaved from its target proteins by UFM1-specific proteases（Uf SPs）,suggesting that the ufmylation modification is reversible.UFM1 cascade is conserved among nearly all of the eukaryotic organisms,but not in yeast,and associated with several cellular activities including the endoplasmic reticulum stress response and hematopoiesis.Furthermore,the UFM1 cascade is closely related to a series of human diseases.In this review,we summarize the molecular details of this reversible modification process,the recent progress of its functional studies,as well as its implication in tumorigenesis and potential therapeutic targets for cancer.
基金supported by grants from the National Key Basic Research Program of China (2004CB518807, 2007CB512403)the National Natural Science Foundation of China (30772004, 30121002, 30600539)the Natural Science Foundation of Shanghai (06QA14069).
文摘We identified a novel ubiquitin-like molecule DULP from human dendritic cells. DULP contains a domain that shares 26% identity and 34% similarity with ubiquitin, and it possesses the corresponding Ile-44 hydrophobic patch used by mono- or poly-ubiquitin to interact with a ubiquitin-interaction motif （UIM） or ubiquitin-associated domain （UBA）. Lysine residue corresponding to 6 of ubiquitin, which is involved in the formation of a multi-ubiquitin chain that can bind proteasomal subunit Rpn10/S5a, is also conserved in its ubiquitin-homology domain. However, DULP does not possess the highly conserved C-terminus Gly-Gly required for ubiquitin conjugation or the Lys-48 required for the formation of polyubiquitin chain to target substrates for degradation, suggesting it might be a novel ubiquitin-domain protein （UDP）. DULP was found widely expressed in many cells and the ubiquitin-homology domain was not cleaved. We also confirmed that DULP expression was enriched in the nucleus and much weaker in the cytosol. Besides, we found that overexpression of DULP in 293T cells induced apoptosis, which might not be associated with the mitochondrial or proteasome pathway, with the specific mechanism remain unclear. Further investigations are needed to identify the precise biological functions of DULP. Cellular ＆ Molecular Immunology.
