Wnt signaling plays an important role in embryogenesis and tumorgenesis. Although the mechanism about how Wnts transduce their signaling from receptor frizzled (Fz) to cytosol has not been understood, dishevelled (Dvl...Wnt signaling plays an important role in embryogenesis and tumorgenesis. Although the mechanism about how Wnts transduce their signaling from receptor frizzled (Fz) to cytosol has not been understood, dishevelled (Dvl) protein was considered as the intersection of Wnt signal traffic. In this study, we characterized the function of three domains (DIX,PDZ and DEP) of Dvl-1 in canonical Wnt signal transduction and Dvl-1 membrane translocation. It was found both DIX and DEP domain were sufficient to block Wnt-3a-induced LEF-1 transcriptional activity and free cytosol β-catenin accumulation; whereas PDZ domain and a functional mutant form of DEP domain (DEP-KM) had no effect on canonical Wnt signaling. In addition, when cotransfected with Fz-7, DEP domain, but not DIX, PDZ or DEP-KM, translocated and co-localized with Fz-7 to the plasma membrane, which was similar to Dvl-1. Furthermore, it was DEP domain that could block Fz-7-induced membrane translocation of Dvl- 1 via a possible competitive mechanism. These results strongly suggest that DEP domain is responsible for the membrane translocation of Dvl-1 protein upon Wnt signal stimulation.展开更多
To investigate correlation of expressions of membrane-type 1, 2, and 3 matrix metalloproteinases (MT1, MT2, and MT3-MMP) to the invasion and metastases in laryngeal cancer. Methods Reverse transcription-polymerase cha...To investigate correlation of expressions of membrane-type 1, 2, and 3 matrix metalloproteinases (MT1, MT2, and MT3-MMP) to the invasion and metastases in laryngeal cancer. Methods Reverse transcription-polymerase chain reaction (RT-PCR) was used to examine the mRNA level of MT1, MT2, and MT3-MMP in 24 patients with laryngeal cancer. The relationships of these three MT-MMP expressions to clinico-pathology were analyzed by statistics. Results The expressions of MT1, MT2, and MT3-MMP were significantly higher in laryngeal cancer tissues than those in para-tumorous tissues (P < 0.01) and had a close relationship with invasive depth (P < 0.05). But no significantly different expressions of these three MT-MMPs were found in different primary location and different histological grade of laryngeal cancer (P > 0.05). The expression of MT1-MMP was obviously higher in patients with metastatic lymph nodes than that in patients without metastatic lymph nodes (P < 0.05). Conclusion MT1, MT2, and MT3-MMP play an important role in the progression of laryngeal cancer, and MT1-MMP may serve as a reliable marker in estimating invasive and metastatic potency of laryngeal cancer. Suppressing expressions of MT1, MT2, and MT3-MMP early may inhibit the invasion and metastases of laryngeal cancer.展开更多
b-1,4-galactosyltransferase (b4Gal-T) (EC 2.4.1.38) plays a multifunctional role in many aspects of normal cell physiology. By now, several dozens of b4Gal-T genes have been cloned, separated from mouse, chick, bovine...b-1,4-galactosyltransferase (b4Gal-T) (EC 2.4.1.38) plays a multifunctional role in many aspects of normal cell physiology. By now, several dozens of b4Gal-T genes have been cloned, separated from mouse, chick, bovine, human, etc. This paper presents the cloning and GST-fused expression of mouse b4Gal-T gene in Escherichia coli (E. coli). The target gene was cloned by PCR, followed by identification by DNA sequencing and expression in E.coli with isopro-pyl-b-D-thiogalactoside (IPTG) gradient concentrations, products of which were separated on SDS-PAGE showing that the target protein had the same molecular weight as that of mouse b4Gal-T. The transcriptional product of b4Gal-T gene was proved by Western hybridization analysis to be due to GST-fusion.展开更多
Hereditary spherocytosis （HS）, the most common cause of congenital hemolytic anemia, is caused by deficiency of the ery- throcyte membrane proteins. Five causative genes （ANK1, SPTB, SPTA1, SLC4AI, and EPB42） have...Hereditary spherocytosis （HS）, the most common cause of congenital hemolytic anemia, is caused by deficiency of the ery- throcyte membrane proteins. Five causative genes （ANK1, SPTB, SPTA1, SLC4AI, and EPB42） have been identified. To date, molecular genetic studies have been performed in different populations, including the American, European, Brazilian, Japanese and Korean populations, whereas only a few studies have been described in the Chinese population. Here, by reanalysis of the exome data, we revealed causative mutations and established a definitive diagnosis of HS in all 38 Chinese families. We found 34 novel mutations and four reported mutations in three known HS-causing genes--17 in ANK1, 17 in SPTB and four in SLC4A1, suggesting that ANK1 and SPTB are the major genes in Chinese patients with HS. All of the ANK1 or SPTB mutations, scattered throughout the entire genes, are non-recurrent; and most of them are null mutations, which might cause HS via a hap-loinsufficiency mechanism. De novo mutations in ANK1 or SPTB often occur with an unexpected high frequency （87.5% and 64.2%, respectively）. Our study updates our knowledge about the genetic profile of HS in Chinese and shows that family-based, especially parent-offspring trio, sequencing analysis can help to increase the diagnostic power and improve diagnostic efficiency.展开更多
Halophilic archaea (haloarchaea) inhabit hypersaline environments,tolerating extreme salinity,low oxygen and nutrient availability,and in some cases,high pH (soda lakes) and irradiation (saltern ponds).Membrane-associ...Halophilic archaea (haloarchaea) inhabit hypersaline environments,tolerating extreme salinity,low oxygen and nutrient availability,and in some cases,high pH (soda lakes) and irradiation (saltern ponds).Membrane-associated proteins of haloarchaea,such as surface layer (S-layer) proteins,transporters,retinal proteins,and internal organellar membrane proteins including intracellular gas vesicle proteins and those associated with polyhydroxyalkanoate (PHA) granules,contribute greatly to their environmental adaptations.This review focuses on these haloarchaeal cellular and organellar membrane-associated proteins,and provides insight into their physiological significance and biotechnological potential.展开更多
文摘Wnt signaling plays an important role in embryogenesis and tumorgenesis. Although the mechanism about how Wnts transduce their signaling from receptor frizzled (Fz) to cytosol has not been understood, dishevelled (Dvl) protein was considered as the intersection of Wnt signal traffic. In this study, we characterized the function of three domains (DIX,PDZ and DEP) of Dvl-1 in canonical Wnt signal transduction and Dvl-1 membrane translocation. It was found both DIX and DEP domain were sufficient to block Wnt-3a-induced LEF-1 transcriptional activity and free cytosol β-catenin accumulation; whereas PDZ domain and a functional mutant form of DEP domain (DEP-KM) had no effect on canonical Wnt signaling. In addition, when cotransfected with Fz-7, DEP domain, but not DIX, PDZ or DEP-KM, translocated and co-localized with Fz-7 to the plasma membrane, which was similar to Dvl-1. Furthermore, it was DEP domain that could block Fz-7-induced membrane translocation of Dvl- 1 via a possible competitive mechanism. These results strongly suggest that DEP domain is responsible for the membrane translocation of Dvl-1 protein upon Wnt signal stimulation.
文摘To investigate correlation of expressions of membrane-type 1, 2, and 3 matrix metalloproteinases (MT1, MT2, and MT3-MMP) to the invasion and metastases in laryngeal cancer. Methods Reverse transcription-polymerase chain reaction (RT-PCR) was used to examine the mRNA level of MT1, MT2, and MT3-MMP in 24 patients with laryngeal cancer. The relationships of these three MT-MMP expressions to clinico-pathology were analyzed by statistics. Results The expressions of MT1, MT2, and MT3-MMP were significantly higher in laryngeal cancer tissues than those in para-tumorous tissues (P < 0.01) and had a close relationship with invasive depth (P < 0.05). But no significantly different expressions of these three MT-MMPs were found in different primary location and different histological grade of laryngeal cancer (P > 0.05). The expression of MT1-MMP was obviously higher in patients with metastatic lymph nodes than that in patients without metastatic lymph nodes (P < 0.05). Conclusion MT1, MT2, and MT3-MMP play an important role in the progression of laryngeal cancer, and MT1-MMP may serve as a reliable marker in estimating invasive and metastatic potency of laryngeal cancer. Suppressing expressions of MT1, MT2, and MT3-MMP early may inhibit the invasion and metastases of laryngeal cancer.
文摘b-1,4-galactosyltransferase (b4Gal-T) (EC 2.4.1.38) plays a multifunctional role in many aspects of normal cell physiology. By now, several dozens of b4Gal-T genes have been cloned, separated from mouse, chick, bovine, human, etc. This paper presents the cloning and GST-fused expression of mouse b4Gal-T gene in Escherichia coli (E. coli). The target gene was cloned by PCR, followed by identification by DNA sequencing and expression in E.coli with isopro-pyl-b-D-thiogalactoside (IPTG) gradient concentrations, products of which were separated on SDS-PAGE showing that the target protein had the same molecular weight as that of mouse b4Gal-T. The transcriptional product of b4Gal-T gene was proved by Western hybridization analysis to be due to GST-fusion.
基金supported by the National Key Research and Development Program of China (2016YFC0905100)the CAMS Innovation Fund for Medical Sciences (2016-I2M-1-002)+3 种基金the National Natural Science Foundation of China (NSFC) (81230015)the Beijing Municipal Science and Technology Commission (Z151100003915078)the Medical Science and Technology Research Projects of Henan Provincial Health Bureau (201601019)the Scientific and Technological Projects of the Technology Bureau of Henan Provincial Technology (172102410010)
文摘Hereditary spherocytosis （HS）, the most common cause of congenital hemolytic anemia, is caused by deficiency of the ery- throcyte membrane proteins. Five causative genes （ANK1, SPTB, SPTA1, SLC4AI, and EPB42） have been identified. To date, molecular genetic studies have been performed in different populations, including the American, European, Brazilian, Japanese and Korean populations, whereas only a few studies have been described in the Chinese population. Here, by reanalysis of the exome data, we revealed causative mutations and established a definitive diagnosis of HS in all 38 Chinese families. We found 34 novel mutations and four reported mutations in three known HS-causing genes--17 in ANK1, 17 in SPTB and four in SLC4A1, suggesting that ANK1 and SPTB are the major genes in Chinese patients with HS. All of the ANK1 or SPTB mutations, scattered throughout the entire genes, are non-recurrent; and most of them are null mutations, which might cause HS via a hap-loinsufficiency mechanism. De novo mutations in ANK1 or SPTB often occur with an unexpected high frequency （87.5% and 64.2%, respectively）. Our study updates our knowledge about the genetic profile of HS in Chinese and shows that family-based, especially parent-offspring trio, sequencing analysis can help to increase the diagnostic power and improve diagnostic efficiency.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2010AA09Z401)National Natural Science Foundation of China (Grant Nos.30621005,30830004, and 30925001)+1 种基金Chinese Academy of Sciences (KSCXZEW-G-2-4)supported by the US National Aeronautics and Space Administration (Grant No.NNX10AP47G awarded to S. DasSarma)
文摘Halophilic archaea (haloarchaea) inhabit hypersaline environments,tolerating extreme salinity,low oxygen and nutrient availability,and in some cases,high pH (soda lakes) and irradiation (saltern ponds).Membrane-associated proteins of haloarchaea,such as surface layer (S-layer) proteins,transporters,retinal proteins,and internal organellar membrane proteins including intracellular gas vesicle proteins and those associated with polyhydroxyalkanoate (PHA) granules,contribute greatly to their environmental adaptations.This review focuses on these haloarchaeal cellular and organellar membrane-associated proteins,and provides insight into their physiological significance and biotechnological potential.
