Non-ionic Detergent (non-ionic + detergent)

Distribution by Scientific Domains


Selected Abstracts


Hypoxia induces expression of a GPI-anchorless splice variant of the prion protein

FEBS JOURNAL, Issue 11 2008
Yutaka Kikuchi
The human prion protein (PrP) is a glycoprotein with a glycosylphosphatidylinositol (GPI) anchor at its C-terminus. Here we report alternative splicing within exon 2 of the PrP gene (PRNP) in the human glioblastoma cell line T98G. The open reading frame of the alternatively spliced mRNA lacked the GPI anchor signal sequence and encoded a 230 amino acid polypeptide. Its product, GPI-anchorless PrP (GPI, PrPSV), was unglycosylated and soluble in non-ionic detergent, and was found in the cytosolic fraction. We also detected low levels of alternatively spliced mRNA in human brain and non-neuronal tissues. When long-term passaged T98G cells were placed in a low-oxygen environment, alternatively spliced mRNA expression increased and expression of normally spliced PrP mRNA decreased. These findings imply that oxygen tension regulates GPI, PrPSV expression in T98G cells. [source]


ISOLATION AND CHARACTERIZATION OF A CELL WALL-DEFECTIVE MUTANT OF CHLAMYDOMONAS MONOICA (CHLOROPHYTA),

JOURNAL OF PHYCOLOGY, Issue 6 2003
Cesar Fuentes
Cell wall,defective strains of Chlamydomonas have played an important role in the development of transformation protocols for introducing exogenous DNA (foreign genes or cloned Chlamydomonas genes) into C. reinhardtii. To promote the development of similar protocols for transformation of the distantly related homothallic species, C. monoica, we used UV mutagenesis to obtain a mutant strain with a defective cell wall. The mutant, cw-1, was first identified on the basis of irregular colony shape and was subsequently shown to have reduced plating efficiency and increased sensitivity to lysis by a non-ionic detergent as compared with wild-type cells. Tetrad analysis of crosses involving the cw-1 mutant confirmed 2:2 segregation of the cw:cw+ phenotypes, indicating that the wall defect resulted from mutation of a single nuclear gene. The phenotype showed incomplete penetrance and variable expressivity. Although some cells had apparently normal cell walls as viewed by TEM, many cells of the cw-1 strain had broken cell walls and others were protoplasts completely devoid of a cell wall. Several cw-1 isolates obtained from crosses involving the original mutant strain showed a marked enhancement of the mutant phenotype and may prove especially useful for future work involving somatic cell fusions or development of transformation protocols. [source]


Evaluation of spore extraction and purification methods for selective recovery of viable Bacillus anthracis spores

LETTERS IN APPLIED MICROBIOLOGY, Issue 2 2001
D.C. Dragon
Aims: To investigate methods of improving anthrax spore detection with PLET. Methods and Results: Comparisons were made of PLET and blood-supplemented PLET to recover and distinguish spores of a variety of Bacillus species. Heat and ethanol purification of spores, and spore extraction from soil with water and high specific gravity sucrose plus non-ionic detergent, were also carried out. Conclusions: PLET was more selective and suitable than blood-supplemented PLET for detection of anthrax spores in the environmental specimens. However, PLET is not an optimal spore recovery medium. Purification of spores with ethanol was as effective as heat purification. High specific gravity sucrose plus detergent extraction solutions may be more sensitive than extraction with water. Significance and Impact of the Study: This study highlights shortcomings with the standard PLET isolation of anthrax spores and describes ways in which the procedure may be improved. [source]


Characterization of Xenopus egg membrane microdomains containing uroplakin Ib/III complex: roles of their molecular interactions for subcellular localization and signal transduction

GENES TO CELLS, Issue 2 2007
A.K.M. Mahbub Hasan
A single-transmembrane protein uroplakin III (UPIII) and its tetraspanin binding-partner uroplakin Ib (UPIb) are members of the UP proteins that were originally identified in mammalian urothelium. In Xenopus laevis eggs, these proteins: xUPIII and xUPIb, are components of the cholesterol-enriched membrane microdomains or "rafts" and involved in the sperm,egg membrane interaction and subsequent egg activation signaling via Src tyrosine kinase at fertilization. Here, we investigate whether the xUPIII-xUPIb complex is in close proximity to CD9, a tetraspanin that has been implicated in the sperm,egg fusion in the mouse and GM1, a ganglioside typically enriched in egg rafts. Preparation of the egg membrane microdomains using different non-ionic detergents (Brij 98 and Triton X-100), chemical cross-linking, co-immunoprecipitation, in vitro kinase assay and in vitro fertilization experiments demonstrated that GM1, but not CD9, is in association with the xUPIII-xUPIb complex and contributes to the sperm-dependent egg activation. Transfection experiments using HEK293 cells demonstrated that xUPIII and xUPIb localized efficiently to the cholesterol-dependent membrane microdomains when they were co-expressed, whereas co-expression of xUPIII and CD9, instead of xUPIb, did not show this effect. Furthermore, xUPIII and xUPIb were shown to suppress kinase activity of the wild type, but not a constitutively active form of, Xenopus Src protein co-expressed in HEK293 cells. These results provide novel insight into the molecular architecture of the egg membrane microdomains containing xUPIII, xUPIb and Src, which may contribute to the understanding of sperm,egg interaction and signaling during Xenopus fertilization. [source]