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Copyright of Cirugía Pediátrica (English Edition) is the property of Sociedad Espanola de Cirurgia Pediatrica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Psoriasin has been identified as a gene that is highly expressed in pre-invasive breast cancer, but is often downregulated with breast cancer progression. It is currently unknown whether psoriasin influences epithelial cell malignancy directly or by affecting the surrounding environment. However the protein is found in the nucleus, cytoplasm as well as extracellularly. In the present study we have sought to identify potential psoriasin-binding proteins and to describe their expression profile in breast tumors. Methods: The yeast two-hybrid method was used to identify potential binding partners for psoriasin. The interaction of psoriasin with RanBPM was confirmed in-vitro by co-immunoprecipitation. The expression of RanBPM and psoriasin was measured by RT-PCR in a series of breast cell lines, breast tumors and primary lymphocytes. Results: We have identified RanBPM as an interacting protein by the yeast two-hybrid assay and confirmed this interaction in-vitro by co-immunoprecipitation. RT-PCR analysis of RanBPM mRNA expression in cell lines (n = 13) shows that RanBPM is widely expressed in different cell types and that expression is higher in tumor than in normal breast epithelial cell lines. RanBPM expression can also be induced in peripheral blood mononuclear cells by treatment with PHA. RanBPM mRNA is also frequently expressed in invasive breast carcinomas (n = 64) and a higher psoriasin/RanBPM ratio is associated with both ER negative (p < 0.0001) and PR negative status (p < 0.001), and inflammatory cell infiltrates (p < 0.0001) within the tumor. Conclusions: These findings support the hypothesis that psoriasin may interact with RanBPM and this may influence both epithelial and stromal cells and thus contribute to breast tumor progression. [ABSTRACT FROM AUTHOR]

Copyright of Biochemistry & Cell Biology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We have studied ceBNIP3, the orthologue of BNIP3 in C. elegans. Sequence analysis reveals that the different domains of BNIP3 have been conserved throughout evolution. ceBNIP3 contains a C-terminal transmembrane (TM) domain, a conserved domain (CD) of 19 amino acids, a BCL-2 homology-3 (BH3)-like domain and a PEST sequence. ceBNIP3 is expressed primarily as a 25 kDa monomer and a 50 kDa homodimer. After transfection, ceBNIP3 protein is rapidly degraded through a ubiquitin-dependent pathway by the proteasome. Like BNIP3, the TM domain of ceBNIP3 mediates the localization of the protein to mitochondria and is also necessary for homodimerization and cell death in mammalian cells. Neither the putative BH3 domain nor conserved domain is necessary for killing. ceBNIP3 protein interacts with CED-9 and BCL-XL, but unlike other pro-apoptotic BCL-2 family members, the BH3-like domain does not participate in dimerization. The ceBNIP3 TM domain mediates interaction with both CED-9 and BCL-XL. ceBNIP3 interacts with CED-3 but co-expression of CED-3 and ceBNIP3 does not significantly enhance induction of cell death in the presence or absence of CED-4. ceBNIP3 kills mammalian cells by a caspase-independent mechanism. In conclusion, we find that although ceBNIP3 interacts with CED-9 and CED-3 it kills by a BH3- and caspase-independent mechanism. Oncogene (2000) 19, 5453–5463. [ABSTRACT FROM AUTHOR]

The yeast two-hybrid system is a molecular genetic test for protein interaction. Here we describe a step by step procedure to screen for proteins that interact with a protein of interest using the two-hybrid system. This process includes, construction and testing of the bait plasmid, screening a plasmid library for interacting fusion proteins, elimination of false positives and deletion analysis of true positives. This procedure is designed to allow investigators to identify proteins and their encoding cDNAs that have a biologically significant interaction with your protein of interest. [ABSTRACT FROM AUTHOR]

A method, using LiAc to yield competent cells, is described that increased the efficiency of genetic transformation of intact cells of Saccharomyces cerevisiae to more than 1 × 10 transformants per microgram of vector DNA and to 1.5% transformants per viable cell. The use of single stranded, or heat denaturated double stranded, nucleic acids as carrier resulted in about a 100 fold higher frequency of transformation with plasmids containing the 2μm origin of replication. Single stranded DNA seems to be responsible for the effect since M13 single stranded DNA, as well as RNA, was effective. Boiled carrier DNA did not yield any increased transformation efficiency using spheroplast formation to induce DNA uptake, indicating a difference in the mechanism of transformation with the two methods. [ABSTRACT FROM AUTHOR]

To identify environmental carcinogens there is a need for inexpensive and reliable short-term tests that can be used to predict the carcinogenic potential of any given substance with high accuracy. The Ames assay, which is based on the induction of mutations in , is the most extensively used short-term test but certain human or animal carcinogens exist that are persistently undetectable as mutagens with the Ames assay or with other short-term tests. There is a need for a short-term test to detect those carcinogens that are missed by the Ames assay. Carcinogenesis is in many cases associated with genome rearrangement. Because of this association a system screening for intra-chromosomal recombination that results in genome rearrangement has been constructed for potential use as a short-term test in the yeast . Evaluation of this recombination system shows that it is readily inducible by a variety of mutagenic as well as non-mutagenic carcinogens, including carcinogens that are not detectable by the Ames assay or by various other short-term tests, such as safrole, urethane, ethionine, auramine, methylene chloride, carbon tetrachloride, cadmium sulfate, aniline, dimethylhydrazine, aminotriazole, acetamide, thiourea and DDE. The present report shows the data for these as well as for additional agents, their response profiles with different concentrations of the agents and the protocol for the DEL system. [ABSTRACT FROM PUBLISHER]